Final ATMS

Solar power: photovoltaics:

"Photovoltaic" solar cells. Growing rapidly in Europe, Japan, China. Expense is an issue: uses pricey raw materials. -Subsidies have been key to make it economically viable. -Prices are plunging though. Especially good for developing countries (can be installed one house at a time). Photovoltaic farms.

Mitigation

(prevent climate change; deal with cause): Reduce emissions of GHGs in order to reduce the amount of climate change that takes place, for example -Energy conservation -Carbon-free energy (wind, solar, nuclear) -Carbon sequestration

Overall target:

32% reduction of electricity emissions by 2030 Compared to 2005 levels Would save over 150 TgC/yr by 2030 (on pace for half a wedge within those 15 years) Different targets for each state

Fuel efficiency:

All of the alternative energies that we have talked about so far have been about generating electricity (or reducing emissions from the generation of electricity, for CCS) But a lot of CO2 is emitted from nonpoint sources- cars, trains, airplanes. -Is there an alternative to the fuel that runs our transit?

Useful facts about CO2:

CO2 per unit energy emitted: -Coal emits 67% more CO2 than natural gas. -Coal emits 30% more CO2 than oil. -Coal is a 'dirty fuel'. US CO2 emissions by energy sources (2017): -Oil 45% -Coal 26% -Natural gas 29% -Renewables and nuclear ~0

Why consider cap and trade?

Cap and trade provided the solution to the acid rain problem in the US (Under George HW Bush, 1990) In general there is broad bipartisan support for these type of market-based solutions Today considered one of the most successful pieces of environmental legislation: 50% reduction in SO2 by 2000 as a direct result

Air Scrubbers:

Chemically remove CO2 by passing air through a scrubber. First plants are just becoming operational. Require millions of these scrubbers (and a lot of money). Phase 1: ambient air is drawn in (a lot). CO2 is bound to the filter. Some systems use a potassium hydroxide solution instead. CO2 free air. Phase 2: once filter is saturated, it is heated. Collected and concentrated.

How are fossil fuels formed? Coal

Coal is formed from plant material that grow in swamps. Covered by sediment and water, then began to decay. Increased pressure and temperature forces water out and creates coal. Process began over 300 million years ago. When it is burned, the carbon is released.

What would regulation of GHG emissions look like?

Economists prefer mechanisms that use market forces to enact changes -Cap and trade -Carbon taxes

Biofuels: What is ethanol:

Ethyl alcohol (the drinkable kind of alcohol). Produced from carbohydrates and yeast. Can be produced from cane sugar, corn, switchgrass.

Weather forecasting:

Getting the timing/location/intensity of a single storm.

Solar Radiation Management:

Goal of solar radiation management: reduce shortwave radiation that gets to the surface -Increases in CO2 emissions have increased the radiative forcing to the surface of the Earth. -SOlar radiation management wants to decrease the sunlight in (shortwave radiative forcing) to balance out the increased greenhouse effect. -If they equal out, the global temperature change should be zero.

Growing wind power capacity:

Growing exponentially. In 2017, there was 23 times the amount that there was in 2001.

Paleoclimate: proxies: ice core data

Ice at the bottom of the Greenland/Antarctic ice sheets are over 100,000 years old.

Local Policies: Seattle:

In 2011, Seattle adopted a goal to become carbon neutral by 2050. 2013 Climate Action Plan provided strategy for reducing GHG emissions. 2017 US withdrew from Paris Agreement, so Seattle responded by affirming commitment to goals established by the agreement (goal is to limit to 1.5C change). GHG are not declining quickly enough to meet goals, but total emissions have declined 6% since 2008, while population increased 13%.

The emissions stabilization triangle:

In order to stabilize concentrations, need to then ramp down emissions. Stabilizing at 500 ppm requires that global emissions are 1.5 Gt/yr by 2100; when this work was published, emissions were ~7Gt/yr (presently ~10 Gt/yr). Should we settle for double (560) or triple (840) pre-industrial CO2? Or more? If we delay the flatlining of emissions, the final Co2 concentrations will be much higher (even if emissions are not much higher). How do we meet the increase in energy demand (projected to increase by 70% by 2050 and 200+% by 2100) without increasing emissions of CO2?

Two immensely valuable consequences:

Isotopes in ocean sediments record glacia ice volume (how much meltwater came off of the ice sheet). Isotopes in ice cores indicates local temperature (how much heavy-isotope snow was able to be deposited on the ice sheet).

Why should we consider it?

Many see slow progress in mitigation efforts. -This could be the only way we avoid serious harm. The potential for unanticipated climate catastrophes. -Example: what if the West Antarctic Ice Sheet started to collapse? Could be a cheaper solution than mitigation. Hard to rule out high climate sensitivities.

The Green New Deal - Goals

Meeting 100% of power demand in the US through clean, renewable and zero-emission energy sources Upgrading all existing buildings for energy efficiency Working with farmers to eliminate agriculture GHG emissions Overhauling transit systems A guaranteed job for every American High quality health care for every American Not yet up for a vote in either the House or the Senate.

For example:

Mitigation is trying to reduce emissions (ex: so temperature changes are lower and flatter) Adaptation is action to avoid harm for a given warming

Nuclear power problems:

New plant construction is rather expensive ($9 million). Waste disposal remains an issue: -Highly radioactive material is produced that must be kept away from people. -Short term storage on-site, but long term storage? -Reprocessing can help but this produces plutonium (can be used in weapons).

Carbon capture and storage:

Not an alternative energy supply, but a way to reduce/eliminate emissions at power plants.

Nuclear electricity:

Nuclear power generation has decreased slightly since 2004. Effort needed by 2055 for 1 wedge: 700 GW displacing coal power (tripling current capacity).

Introducing the idea of global warming:

Observed warming between 1973 and 2000 was between 0.51 and 0.56.

Solar power: passive:

Passive solar: doesn't use mechanical or electrical equipment. -Uses sunlight to reduce heating/lighting/ventilation costs. -E.g., south facing windows (in Northern Hemisphere) for more winter sunlight.

Two types of carbon sequestration:

Processes that remove carbon from the atmosphere (increased forestation). Processes that capture carbon dioxide at its source and it is subsequently stored in non-atmospheric reservoirs- Carbon Capture and Storage (CCS). -CCS can capture up to 90% of the emissions produced by burning fossil fuels at power plants/industrial factories. Capture technologies.

Geoengineering: approaches: Capturing carbon from the air:

Removing CO2 from the atmosphere after it has been emitted. Lots of excitement and research about this right now. -But $$$- currently tech is being funded by philanthropists like Bill Gates.

International agreements

Rio Kyoto Copenhagen Paris

How should regulations be apportioned?

Should regulations be based on how much has already been put out? How much is used? Produced? A country's population? A country's wealth? What if those things change?

The wedge strategy - Interim goal:

Stabilize emissions immediately (yet increase energy by ~70$ in 2054) and invest in technology to have much more energy with reduced emissions after that. Need to make up the difference between projected energy needs and flat path with a "stabilization triangle". Stabilization triangle: between currently projected path and flat path. This is where all of the technology will come from to keep civilization thriving.

Over billions of years:

Sun and earth were born 4.6 billion years ago. In the future, we expect it to heat up to a point that life on earth is impossible, then shrink and fade.

Disinformation/ framing tactics:

The approach to creating disinformation is actually rather systematic! -Lots of focus groups are tested for which messages they respond to. -Most effective messaging strategy is selected, without regard for truthfulness.

What's appealing about wedges:

The stabilization triangle: -Does not concede doubling CO2 is inevitable. -Shortens the time frame t within business horizons. The wedge: -Decomposes a heroic challenge (the stabilizatioon triangle) into a limited set of monumental tasks. -Establishes a unit of action that permits quantitative discussion of cost, pace, risk, trade-offs, etc. The wedge strategy: -Does not change the fact there are winners (alternative energies) and losers (coal and oil become more espensive sources of energy), but brings many options to the table.

Fill the Stabilization Triangle with Seven Wedges:

There are 14 different options for this! Each challenging but feasible.

Summary of the Debate:

There is consensus among climate scientists that the climate is changing, and that anthropogenic emissions will continue to alter the climate system. Climate science follow rigorous scientific rules and peer review. There is disinformation spread that aims to redirect the debate or add uncertainty. Went through examples of some typical arguments of climate deniers/skeptics- but there are plenty more. The representation of climate in the media + people's belief systems have led to "Six Americas" in terms of climate change.

In order to stabilize concentrations:

To stabilize at 450 ppm drastic and immediate emissions cuts are necessary. -Emissions must plummet and we probably have to take some CO2 out of the atmosphere. 350.org: -Worldwide climate action group started by Bill McKibben (wrote the end of nature, first major book on global warming).

Wind power: US:

US could be the world leader in wind. Could provide 9 times US electricity usage just in lower 48 states.

Climate policy: international policy: a very brief history

United nations conference on the environment and development (UNCED) "Earth summit" -Rio de janeiro, brazil, june 1992 Resulted in a treaty known as the UN framework Convention on Climate Change (UNFCCC) Annual meetings of the UNFCCC parties are called conferences of the parties (COP) -Kyoto protocol was negotiated at COP 3 in 1997 -Copenhagen was COP 15 in 2009 -Paris was COP 21 in 2015

Solar power: solar power towers:

Use mirrors to concentrate the sun's rays onto a tower or series of pipes that hold fluid. Boi fluid → steam → spin turbine. Produces steam for electricity, or hot water/warm air for homes, industry.

Paleoclimate: volcanoes:

Volcanoes cause a cooling on short timescales. Remember that we talked about Pinatubo and aerosols? Over very long timescales, can add significant CO2 to the atmosphere. Volcanoes release aerosols that block solar radiation

Effect of volcanoes on land precipitation:

Volcanoes have been shown to reduce the amount of land precipitation and disrupt monsoons.

Alternative energy sources:

We already have effective ways at generating CO2 - free electricity. -Renewable energy: generated from natural sources such as solar, wind, tidal, geothermal, and hydroelectric. -Nuclear is not renewable, but it also doesn't emit CO2.

2017: I-732 in Washington State:

We had a revenue-neutral carbon tax on the ballot in WA in 2017- returns all revenue as tax cuts, leaving none for govt. To spend. -It did not pass but got around 40% of the vote. I-732 would have actually lowered sales tax by a percentage point. -Tax would have come from gas and utility use. -Also credits for businesses and low income families. Opposed by many green groups- felt it was incomplete and insufficient. -Developed their own initiative, I-1631.

How should regulations be doled out?

What is fair for per-capita increases? -IPAT -World population increases -Contract and converge -Emissions in developing countries

Profound and unaddressed issues associated with geoengineering:

Who decides if it should be deployed, and at what level? Who decides if it should be stopped? -What if one country decides to do it on its own, even though it harms another country? There are important cultura, legal, political, and economic implications of geoengineering. How will they be balanced? Moral hazard: -If we have a possible solution to global warming, will we be less inclined to reduce carbon emissions? We can't rule out unanticipated harmful and perhaps irreversible consequences.

What kind of info can you get from an ice core?

Bubbles trapped in ice tell you about atmospheric composition over time. Thickness of layers in the ice tell you about precipitation rates over time. Isotopes of hydrogen and oxygen in the ice tell you about temperature.

Hot climates of last 250 million years:

CO2 levels were several times higher than present. -Estimates between 500 ppm and 3,000 ppm. -We know this from many lines of evidence: isotopes in rocks/fossils, examination of plant fossils, carbon cycle models. Why was there an excess of CO2? -Increased undersea volcanic activity was likely important for releasing more CO2. -Plates were separating quickly back then, causing more volcanoes.

Cloud parameterizations:

Cloud interactions are the most uncertain process in GCMs. -Lead to the largest differences among models. -Therefore contribute uncertainty to future climate.

Summary of Paleoclimate:

Earth's climate is set by: Sunlight, Earth's orbit, location and movement of continents, and volcanoes. We can estimate past climate from proxy records. There have been really extreme climates in the past. -Snowball Earth. -Hothouse climates The quaternary ice ages are caused by variation in relationship between the Earth and the sun. -CO2 is a feedback during ice ages, not a forcing (like in the present) -The signature of the ice ages is well preserved in ice core and ocean sediment core records. Emerging from the most recent ice age was bumpy but the last 10,000 years have been a time of relative quiet in the climate. -Still plenty of variability in space and time, but not as extreme. -Previously identified warm and cold periods in the last few thousand years probably weren't global but were still important to the populations that lived there.

Isotopic evidence:

Evaporation leaves heavier isotopes in the ocean. Evaporation prefers the ones who are easier to pick up, thus, O16. It picks up some of the heavier isotopes but will be enriched by lighter ones. Winds transfer precipitation closer to the poles. It is colder closer to the poles so it condenses and starts to rain out. Rain drops the heavier isotopes. Rains out extra O18 -Rain prefers to drop the heavier isotopes. In colder climates, most of the heavy precipitation falls out over the ocean (to cold to hold moisture over the ice sheets). -Therefore there are a lot of heavy isotopes in the ocean. Evaporation favors light. Rain favors heavy. Cloud above ice is enriched in light isotopes.

Scientific assessments:

For important societal issues (energy, stem cells, wetlands, etc), there are assessments of the state of the science. -Intergovernmental panel on climate change (IPCC) does this for climate change. IPCC summarizes the current climate research every 5-7 years. -Like peer review of the whole state of the science. -Tends to be pretty conservative in terms of scientific claims. -1000s of pages of reports. -Most recent was 2018. -Next report coming out in 2021. -Several contributions are from UW. Many scientific societies have put out consensus statements agreeing that humans cause climate change and global warming will get worse. And at least 200 other international scientific organizations have also agreed.

More components of GCMs:

Heat sources: -Shortwave and longwave radiation. -Condensation. -Surface fluxes. Have to parameterize (approximate) small-scale processes. -Clouds. -Moist convection.

Components - the grid:

Horizontal grid: latitude- longitude. Vertical grid: height or pressure. Climate models chop up the earth into grid cells. Close up of europe: -The current horizontal size of an atmosphere, land, ocean or sea ice grid cell is about 100kmx100km. -The vertical extent of a box is typically: atmosphere/ocean: 80-500m, sea ice: 50cm, land: 10cm. Model resolution evolution: -Changes in resolution over time. -AR: assessment report of IPCC. -FAR: first IPCC assessment report . -Model resolutions improve as computing power gets cheaper.

Snowball Earth:

Imagine a runaway ice-albedo feedback. Less incoming solar radiation for some reason (say a super volcano). Earth cools down. Ice area expands and more sunlight reflected away. Earth cools some more. Repeat until most incoming sunlight is reflected away instead of being absorbed. Snowball Earth occurred several times in the last billion years when ice-albedo feedback spiraled out of control.

Post-Snowball "Hothouse" Climate:

Immediately after Snowball Earth thaws, CO2 concentrations would have been tremendously high. Was likely the hottest period in Earth's history right after the coldest. Temperatures jumped from -50C to 50C in only 1000 years Massive weathering would gradually bring down CO2 and temperatures

Isotopic data:

Many of the previously mentioned datasets can be dated using carbon dating or other radiometric dating techniques. Also, isotopes can tell us about precipitation and temperature. Isotopes of an element have the same number of protons but different numbers of neutrons in their nuclei. Carbon can have 12, 13, 14 neutrons. Have a good idea of the proportion of each found in nature. Carbon-14 is radioactive. Produced continuously in the Earth's uppe. Becomes mixed with the nonradioactive carbon in the carbon dioxide of the air, and it eventually finds its way into all living plants and animals. After the organism dies, Carbon-14 begins to radioactively decay at a known rate. By measuring the amount of radioactivity remaining in organic materials, the time of death can be determined.

Paleoclimate: previous warm climates:

Mesozoic (250-65 million years): -Triassic, jurassic, cretaceous -Time of the dinosaurs: -2-6 deg C warmer globally -Poles were especially warm Warm-adapted animals found at high latitudes Warm-adapted evergreen vegetation found above Arctic circle -Leaves of breadfruit tree found in Southern Greenland -Today breadfruit found in tropical to subtropical environments Coral reef evidence indicative of warm tropical waters found within 40 degrees of equator

Other successful predictions of climate models:

More warming at night than day. Most warming in arctic than anywhere else )especially during winter). Least warming around antarctica. Wet regions get wetter, subtropical regions dry. Expansions of deserts. Tropopause (top of weather layer) moves upward. Large scale tropical circulations weaken.

Isotopic evidence from ice cores

Most often measured isotopes are oxygen isotopes. -0-16 is lighter and evaporates more easily. -0-18 is heavier thus more likely to fall out and rain out more easily. (it has two extra neutrons) -Both are stable isotopes (don't decay over time) The relative amount of 0-16 to 0-18 frozen in the ice is related to temperature, so we can use the ratio of 0-16 to 0-18 as a proxy record.

The role of continental drift:

Movement of Antarctica over the South Pole. Allowed an ice sheet to form - higher planetary albedo. Decline in atmospheric CO2 starting 60 million years ago. -Coincides with the rise of the Himalayas and Rockies. --More weathering as fresh rock exposed. -Also there was a concurrent slowdown in continental drift. --Less volcanism, less CO2. Closing of the isthmus of Panama was the last major change to the land distribution (about 4 million years ago). Last 35 million years (since end of early cenozoic): -Earth slowly cooling down. -Life retreats from poles. -Polar ice caps established. -Most recent ice-age cycles begin ~3 million years ago.

Other uncertainties and limitations:

Oceans can be tricky to model: -Small scale mixing at the surface, and exchange between the surface and deeper waters - hard to observe hard to model. Ice sheets are tricky too. -Ice dynamics are also difficult to observe and to model. -Particularly difficult to couple to the ocean.

Why is it difficult to galvanize action?

Requires personal sacrifice. Requires political cooperation. Requires corporate cooperation. The scope of the problem is huge. Political polarization. Fear based rhetoric makes people defensive/resistant. misinformation /confusion.

Forecast with filtering:

Short-range forecast of sea-level pressure, from filtered data. The contour interval is 4 hPa. Single forward time step of size t=3600s.

Self proclaimed "think tanks":

Some think tanks instead exist to help achieve a desired social, financial or political outcome, based on a perceived threat or opportunity. These think tanks may use disinformation and/or scare tactics to achieve their ends. -Both liberal and conservative examples of this! -Financing is often provided by the entities they serve. -Examples in climate arena: --Heartland institute --Competitive enterprise institute --Cato institute --Marshall institute

Over hundreds of years:

Some variability over the past 1000 years. Warming due to anthropogenic forcings begin 1850. Unclear how human behavior and feedbacks will change the climate in the geologically near future.

What causes ice age cycles?

Temperature goes up before CO2 goes up. We think CO2 is making temp rise, but it isn't driving ice ages. Is carbon dioxide the driver of ice ages? NO. In this case, CO2 was acting as a feedback not a forcing. Don't tip us in and out of ice ages. Once we start warming, then more CO2 is released, further amplifying the warming. Strong feedback. -CO2 changed due to temperature changes, and amplified the changes (positive feedback). The driver is changes in solar radiation due to changes in Earth's orbit around the sun.

Medieval warm period (1000-1300 AD):

Temperatures in some parts of the world were close to modern day (Europe, North Atlantic).

Paleoclimate: location of the continents:

The continents have shifted with time (tectonic plate movement). Mountain ranges appear. Ocean and atmospheric circulations change with the shifting continents. Need continents near the poles to grow ice sheets.

10 million years ago:

The earth experienced a gradual and jumpy cooling over the last 55 million years. In the past 2.7 million years, glacial and interglacial periods fluctuated.

Quaternary period

The ice ages -The ice ages lasted 2.7 million years before present to about 10,000 yrs ago --Large ice sheets covered northwestern europe and northern north america What does an ice age look like? -Reconstruction of land and sea ice 21,000 years ago The last glacial maximum (LGM) occurred around 20,000 years ago Sea level was lower by ~120 m at the time of the LGM because of the storage of water in the continental ice sheets. What did it look like in North America? Present day ice sheets provide excellent records of the past! Ice cores have been taken from Greenland and Antarctica -Up to 800,000 year old ice! -Up to 3700m deep! Glacial striations: marks left by the glaciers

Paleoclimate: orbital variations:

The orbit of the Earth around the Sun. If the solar system was just the Earth and Sun, the orbit would be a perfect ellipse that never changed. However, other planets/moons in the solar system cause the orbits to change with time. Also the Earth's orientation toward the sun changes over time.

Drawbacks:

The people who have collected and processed the data usually want to get published before sharing (so their work doesn't get scooped up by someone else). Who will pay for publication costs?

Why are we confident that scientific studies are right and unbiased?

The rules of science: -In any study, you are required to: --Describe your methods exactly. Well enough so that anyone else can repeat your work. --Mention all assumptions you made and why. -Further, most data/models are publicly available so it's not that hard to check methods/procedures yourself. --Exceptions are proprietary datasets that are used to make money.

Climate modeling: climate sensitivity:

The sensitivity of a global model is usually defined as the amount of temperature change that the model produces in response to a doubling of CO2 from pre-industrial levels. -Convenient target with which to compare models. -Could also ask how it would respond to a tripling or halving of CO2. -Other researchers try to estimate the sensitivity using paleoclimate information. Most major coupled models put the sensitivity around 3.0 degrees C. -The uncertainty for what the sensitivity truly is comes from uncertainty in feedbacks. -There is a small chance that the sensitivity is higher (8.0 degrees C).

Eccentricity:

The shape of Earth's orbit changes about 3 degrees from more elliptical to more circular over 100,000 year cycle. Every 100,000 we go from an almost perfect circle to more of an ellipse. Ellipse= close to the sun. Round= far from the sun. When the orbit is highly elliptical, the amount of insolation received at Earth's closest approach to the sun would be 20-30% greater than at furthest departure.

Paleoclimate: the sun!

The sun It has changed in magnitude over its lifespan. Over the last billion years, its radiation increase 10%. Initially 75% as strong as it is now. Faint Young Sun Paradox: Raised by Carl Sagan in 1972. Earth was warm most of the time when the sun was weak. We know about the warmth from geologic evidence: rounded pebbles, mud cracks, ripple marks indicate water-driven erosion, microfossil algae indicate presence of early life. High greenhouse gas concentrations are likely the key to have kept it warm.

During ice ages:

The water in the ocean has a relatively high amount of heavy oxygen. The snow that is deposited in the ice sheets has a relatively high amount of light oxygen.

Richardson's experiment:

Used data from May 20, 1910, when Halley's Comet was passing through the atmosphere. Used surface temp and pressure, upper atmosphere and temp. Tabulated values from these charts by hand.

Performing an experiment that is not reproducible:

We want information beyond when the data was collected. Can get answers with climate models.

Previous warm climates

65 million years ago dinosaurs went extinct. -Due to meteorite impact. Warm climates persisted for a while after though. Huge and rapid warming event: paleocene-eocene thermal maximum. (this was the Eocene Optimum, there is the PETM here, has a huge spike in temp).

Nuclear power Yucca Mountain Nevada:

US has been looking for a potential deep geological storage facility for spent nuclear fuel. ~80 miles NW of Las Vegas. Approved in 2002 because it is geologically boring and there is little chance of earthquake/ any other natural disaster; but lots of debate in the courts and with different administrations since then because people who live nearby aren't happy about this. No long-term storage site for material in the US. Seismic hazard: nuclear reactors in places with a probability of an earthquake could cause an explosion.

Geothermal power worldwide:

US is top producer (2.5 GW) in terms of total capacity. Over 15% of the electricity generation for the countries of Iceland, Philippines, El Salvador, Costa Rica, and Kenya. California is #1, Nevada is #2, Utah is #3, Hawaii is #4. We can also use geothermal heat directly (no power plant or heat pump, just a road heating system which melts ice instead of having to plow).

Hydropower requires damming rivers:

Unfortunately, the dams that are constructed to provide hydropower also interrupt natural ecosystems. If you block river's natural flow, there are effects: -Sediment that would normally be washed down by the river is trapped behind the dams (instead of moving downstream). -Salmon are impeded from moving upstream. Recently dams along the Elwha river on the Olympic Peninsula (of WA state) were removed because of the problem it had been causing to the ecosystems.

Biochar:

Burning biomass without oxygen (pyrolysis) creates biochar. -Stable form of carbon that cannot escape easily to the atmosphere. -Can be made in biomass synfuel plants (half the carbon goes into fuel, half into char). Can be buried in the ground to sequester carbon. -Also improves soil quality: nutrients, water holding quality, buffering. Could help developing countries slow deforestation, improve food security, provide renewable energy, and sequester carbon. Taking CO2 out of the atmosphere at a large scale with biochar may be possible. -Currently projects are extremely small but all technology is there. Why not take forest mass killed by bark beetles to make sunfuel and biochar? This is a rarely mentioned, possibly very important element of solutions to global warming. -Could draw down 100 gt C in the next 50 years.

Other potential problem with wind power: harms birds:

But all human structures harm bird life. -Wind farms are a small fraction of the human harm to birdlife (shiny buildings are the worst for this). Careful placement away from migration patterns can help prevent harm.

California Cap and Trade:

California has a history of leading the way on environmental reforms. -Air pollution, standards, efficiency of appliances/vehicles, etc. Passed in 2006, began in 2012. -Ballot initiative in 2010 tried to repeal, handily defeated (61%-39%). -Some allocations to industry, and auctions to utilities/transport. -Efficiency programs, support for renewables, agriculture, transportation, industry, forests, waste/recycling are all included.

Biofuels: What is biodiesel?

Can be burned in diesel engines. Derived from plant oils and animal fats. -Soybean oil, canola oil, restaurant grease.

Why is there a lot of debate?

Carbon dioxide and other GHG are invisible. The worst effects may occur: -Far away. -In the future. We all produce GHG emissions in our day-to-day lives (instead of a few "bad guys"). Some powerful industries have a lot of $$$ at stake.

I-1631 in Washington State:

Carbon emissions fee and revenue allocation on ballot in November 2018. Fees are invested in programs to support clean energy, efficiency, forests. Relatively low price on carbon compared with I-732. -Cuts in carbon would be facilitated by investments with the revenue in addition to the fee. Failed to pass, 56%-44%.

Weather prediction:

Climate models are closely related to weather prediction models. Let's discuss some history of weather prediction: -1904: Vilhelm Bjerknes from the University of Stockholm showed the interaction between fluid dynamics and thermal dynamics - suggested that it would be possible to forecast the weather by solving equations. How winds move and how heat moves. -The first attempt at numerical weather forecasting by Lewis Fry Richardson.

GCMs components - clouds:

Clouds are much smaller than a 100km pixel. Clouds and other small-scale processes must be approximated or "parameterized". For instance, clouds may be made a function of humidity.

British Columbia Carbon Tax:

Enacted in 2008, places a cost on carbon emissions from coal, oil, natural gas. -Works out to about 25 cents per gallon of gas. It's "revenue neutral" meaning all the proceeds are given back to consumers. -3B dollars to business tax cuts, 1B dollars to personal tax breaks, 1B dollars to low income tax breaks. -Income tax rates in BC are now lowest in Canada b/c of this. Has worked pretty well. -Reduced emissions 15% compared to what they would have been. Fuel usage dropped compared to rest of Canada. Generally strong support for this program (55%-65% approval, a lot for a tax).

Emissions in developing countries

Encouraging sustainable, low carbon development will be an important aspect of the future fight against global warming -This can be done in ways that also have benefits for human health, quality of life, reduction of poverty, etc

Competitive Enterprise Institute (CEI):

Founded in 1984. Historically, mainly funded by Exxon Mobile. -Also, the American Petroleum Institute, Koch Family Foundations, Cigna Corporation, Dow Chemical, EBCO Corp, General Motors and IBM. CEI mission statement: "CEI is a non-profit public policy organization dedicated to advancing the principles of free enterprise and limited government. We believe that individuals are best helped not by government intervention, but by making their own choices in a free marketplace".

Alternative energy geothermal power:

-Comes from heat within the Earth. --Heat is continuously produced within the Earth by the slow decay of naturally occurring radioactive particles (+ some heat from when planet was formed and friction from the core sinking). -When magma comes near the surface of the Earth (often near tectonic plate boundaries), it heats groundwater trapped in porous rock. -Very steady source (no problems with intermittency).

Fuel efficiency in the US:

Fuel efficiency up since 2005, after a long plateau. US fuel economy (35 mpg) is much less than Europe and Japan (45 mpg). GW Bush in 2007: 35 mpg by 2020. Obama in 2011: 35.5 mpg by 2016, 54.5 mpg by 2025.

Ways to validate climate models:

How much cooling after volcano? Can we reproduce the last ice age conditions given CO2, solar radiation, etc conditions? Can the climate of the 20th century be reproduced given greenhouse gas, solar, volcanoes and aerosols activity. How about forecasts for the future of the climate? Look at old climate models and see how good they were at predicting the future.

What's a fair rate of emissions for a given country?

How to find a way that allows economic growth in developing countries without cutting into wealthy nation's economies so much that they opt out? -A path to get there: --Contraction: reducing overall global emissions to reach a target CO2 level --Convergence: global per capita emissions should converge toward a common amount --This would mean US emissions would have to drop an especially large amount -Not a perfect strategy but a possible framework

Biofuels: Where in the world?

Huge in Brazil (25% of their fuel is from sugar cane). We make more in the US, but from corn. -Much less efficient than sugar cane- high carbon footprint.

Nuclear power production:

Huge proportion in France (80% of electricity there). 99 nuclear plants in the US. -No new constructions between 1979 and 2013. -Currently 2 reactors under construction (others recently cancelled). Many foresee a "nuclear renaissance" to help move towards carbon zero energy.

Hybrid electric vehicles:

Hybrid vehicles run off of two propulsion systems: internal combustion and electric. -Ex: toyota prius (Creates its own electricity), Chevy Volt (plug in hybrid). Environmental concerns: -Requires large battery packs, which have toxic materials in them. -Some rare materials used are becoming more scarce, harder to obtain. 100% electric vehicles use only electricity for propulsion. -Example: Nissan Leaf. Does not emit CO2 from the tailpipe, but the electricity source when you plug it in needs o be carbon free too.

Numerical weather prediction:

Improvements in weather prediction over the last 60 years are among the most impressive accomplishments of society. Some extreme events have been predicted with accuracy. -Hurricane sandy's path and intensification was predicted 8 days ahead . -The 2010 russian heat wave were forecast with 1-2 weeks lead time. Weather models and climate models are similar in a lot of ways: -Use very similar mathematical equations. But weather forecasting and climate forecasting have very different goals: -How can we predict the climate in 50 years if we can't predict the weather 2 weeks from now?

Paleoclimate: proxies: ice core data:

In the bubbles, as they transition from snow to ice- the atmosphere is trapped at the moment the bubbles are sealed off. So can get what the composition of the atmosphere was. In the ice- can look at the chemistry of the ice to tell us about the temperature when it was deposited. In the ice- can look at the thickness of annual layers in the ice to get information about precipitation rates. Geologic data: rocks, sediment, shape of the land.

Clean power plan repealed by EPA Admin Scott Pruitt in October 2017

Instead give individual states more authority to make their own GHG emissions plans Lawsuits frmo states (including WA) have so far been unsuccessful Supreme court rules 5-4 that no further appeals of the repeal would be allowed

Since MA vs EPA, EPA has enacted

New regulations for light duty vehicles (2010) Rules for construction of new power plants (2012-2014) -Less than 1100 lb of CO2 per kWh (hard for coal) Clean power plan (2015)

Why were sea levels so high?

No ice sheets at all. Thermal expansion of seawater. Ocean was less deep (tectonic activity). These factors led to 200 meter higher sea levels.

Can dimming the skies perfectly cancel CO2?

No! Solar radiation and greenhouse gases have different effects. Greenhouse gases have a different signature than solar forcing. -This is used in attribution studies that show we caused the warming. Greenhouse gases warm nights more. -Geoengineering would cool days more.

Nuclear power growth/decline:

Nuclear power grew rapidly in 1970s-1980s, but has not grown since ~2000. Went down in mid 2000s.

Nuclear power: how is it generated?

Nucleus on an atom splits to form 2 or more smaller nuclei. Some of the mass is converted to electromagnetic radiation and kinetic energy - and a chain reaction continues the process. Nuclear power plants induce this reaction . This energy is captured to: -Heat water. -Which makes steam. -Which can turn a turbine.

Capturing carbon in the emission stream:

1. Capture- separate CO2 from other gases produced at large scale facilities. 2. Transport- the CO2 is compressed and transported via pipeline or trucks/ships to a suitable site for... 3. Storage- CO2 is injected deep into underground rock or salt formations. Pumping CO2 below ground is already a strategy used to extract more oil/natural gas- so energy companies like this technology. Requires large amount of energy. -Increases the fuel needs of plants by 25%-40%. Makes energy from coal expensive compared to many other sources, including renewables. -Could double the cost of energy from coal. Works from CO2 emitted from power plant facilities, but no applicable to non-point sources (CO2 emitted from tailpipes). Risky if CO2 escapes from storage.

Geothermal power: how?

1. Hot water (or steam) is pumped up from under the surface of the Earth. 2. When the water reaches the surface, the pressure is lower, so it turns into steam. 3. Steam spins a turbine, connected to a generator - makes electricity. 4. Steam cools and condenses. 5. Water is pumped back into the earth to begin process again.

Two main strategies to geoengineering:

1. Solar radiation management - a. Blocking out the sun to cool the Earth back down. This is what most people are talking about when they refer to geoengineering. - b. taking CO2 out of the atmosphere.

How are fossil fuels formed? oil

1. plants and animals die and sink to the bottom of the sea 2. plant and animal layer gets covered with mud 3. over time, more sediment creates pressure compressing the dead plants and animals into oil 4. oil moves up through porous rocks and eventually forms a reservoir

The original new deal

1933-1935- Franklin D Roosevelt created jobs through the Tennessee Valley Authority (building dams for hydropower) and Works Progress Administration (building post offices, bridges, schools, etc). Also signed the Social Security Act.

Geoengineering: history:

1974: Mikhail Budyko (russian climatologist; one of the first scientists in the field of the physics of climate) proposed injecting sulfur dioxide in the stratosphere to cool the earth (like volcanoes). Early 1990s: Edward Teller and collaborators proposed putting designer (nanotech) particles into the stratosphere to deflect sunlight. -Teller was father of the H-bomb, principal architect of "Star Wars" defense initiative, and inspiration for Dr. Strangelove. 1992: The National Academy of Sciences issues a detailed study of geoengineering options, including a cost-benefit analysis for each option. 2006: Paul Crutzen (Nobel Prize winner for ozone hole) says we should consider it.

What do people think? The debate:

2018 poll from Yale on global warming: -70% of americans believe global warming is happening. -But 28% believe there is a lot of disagreement among scientists about whether global warming is occuring. --There is actually very little disagreement among scientists about whether global warming is occuring (even some of the strongest skeptics like Lindzen, Christie, etc). --97% of climate scientists agree

What is a wedge?

A "wedge" is a strategy to reduce carbon emissions that grows in 50 years from zero to 1.0 GtC/yr. Cumulatively a wedge redirects the flow of 25 GtC in its first 50 years. The interim goal (no further increase in emissions) is within reach. Reasons for optimism that global emissions in 2055 need not exceed today's emissions. The world today has a terribly inefficient energy system. Carbon emissions have just begun to be priced. Most of the power plants of 2055 have not yet been built.

Cap and trade

A cap (or limit) is set on the amount of a pollutant Polluters are given or auctioned permits that allow a certain number of pollution allowances. The total allowances cannot exceed the cap Polluters may trade allowances -Buyers pay to pollute, and sellers get a reward for reducing emissions more than they were allowed to

Local Policies: Policy changes to get there:

A few that have already been done: -Transit investments (light rail, bike infrastructure, electric vehicle charging pilot program). -Owners of non-residential and multi-family buildings must track energy performance and report to the city. -Incentives to convert your house from oil to heating. A few plans for the future: -Tolling/road pricing → revenues goes to expanded transit. -Developed recommendations for making all new taxi/ride share cars to be electric. -Improve municipal building energy efficiency.

The "Wedge Strategy" to stabilize CO2:

A strategy proposed to drastically reduce emissions without decreasing economic growth. -In fact, it assumes large increases in energy usage. All options are on the table: -Even some that are clearly less efficient or more expensive than others. Stabilizing atmospheric CO2 at ~500 ppm: -In 2004, Pacala and Socolow proposed a plan to achieve this goal: --Phase 1: no further increase in emissions until 2054, with energy production still increasing rapidly. Ramping up existing technologies to do this. --Phase 2: After 2054, rapid reductions in global emissions. Final emissions of all GHG must level off by ~2100 to ~1.5 Gt/yr or ~20% of present global emissions.

Kyoto Protocol, 1997

A treaty with mandatory emissions reductions Goal: to prevent dangerous anthropogenic interference with the climate system Annex 1 countries: developed nations that agreed to take the lead in reducing GHG emissions Emission targets: -Reduce emissions by 5.2% on average from 1990 emissions -To be achieved by 2012 Complementary actions to promote sustainable development, share, technology, ease economic impacts

Motivation:

Alternative to "costly" inorganic polycrystalline Si: organic polymer solar cells (OSCs). -Synthetic variability. -Lightweight, clean, flexible. -Low-cost fabrication. >10% efficiency required for market relevance. -Difficult to achieve in OSCs.

Motivation::

Alternative to costly inorganic polycrystalline Si: organic polymer solar cells. -Synthetic variability. -Light wright clean and flexible. -Low cost fabrication. >10% efficiency required for market relevance. -Difficult to achieve.

Local Policies: University of Washington:

At UW our emissions come from: -Electricity generation (4.5%). -Commuting (40%). -The power plants (55%). -Goals toward reduction are laid out in the university's Climate Action Plan. 2020 target: 171,000 mtCO2 equivalent (15% below 2005 level). 2035 target: 129,000 mtCO2 equivalent (36% below 2005 level).

Other effects of Dimming the Skies:

Ocean acidification would continue. -Remember this just depends on atmospheric CO2 levels. -Large effects on marine life would not be prevented. Effects on plant growth? -They need sunlight. -Solar radiation management decreases yields by reducing available sunlight for photosynthesis. -Solar radiation management increases yields by reducing heat stress. -Pros are on par with the cons (globally there will be local winners/losers). -Model inferences based on how crop yields responded to large volcanic events. Precipitation has a different sensitivity to solar vs greenhouse gases. -Geoengineering should dry out the climate more (solar radiation helps evaporate more water vapor from the surface).

Pros vs cons:

Pros: -Reduces CO2 emissions from existing power plants. -Can be implemented in a way that does not lead to a wholesale change of how we get electricity/produce goods now. -Can help act as a bridge as other clean energy technology is implemented. Cons: -Expensive to build facilities, pipelines. -Requires a lot of energy, so it would increase the costs of generating electricity through fossil fuels. -Pumping CO2 in the ground can lead to a seismic activity.

Biofuels pros and cons:

Pros: -Reduces NET CO2 emissions. --CO2 is emitted but it came from plants which recently took that CO2 from the air. -Better for human health. --Reduced carbon monoxide and particulate emissions. -Less unburned hydrocarbon emissions. -Reduced acid rain potential: no sulfate emissions. -Energy independence. Cons: -Not actually carbon neutral. --Need energy to grow, ship, process. Demand removes forested land. -May be worse for human health in some ways via NOx emissions (a key bad ozone creator). -Expensive. -Less land for food production: people compete with machines for food. pure/high ethanol is not approved for most cars okay as an additive.

Geothermal power pros and cons:

Pros: -Reliable supply. -Relatively simple facilities. -Inexpensive. -Small land footprint compared to wind and solar. Cons: -Regionally limited. -Releases a little CO2 and other more harmful gases from ground (only 1-4% of the amount emitted by coal plants). -Enhanced geothermal systems have caused seismic activity during construction.

What are the goals?

RCP- representative concentration pathways. Projected scenarios for the future. Numbers are the radiative forcing it ends up at by 2100. Selected and defined by their total radiative pathway and level by 2100. RCP 2.6 (green)- represents scenarios that lead to very low GHG concentration levels. Small peak and then decline. RCP 4.5 (red) - total radiative forcing is stabilized shortly after 2100. RCP 6 (black) - total radiative forcing is stabilized shortly after 2100, but different strategies. RCP 8.5 (blue) - increasing greenhouse gas emissions over time.

Regional Greenhouse Gas Initiative (RGGI):

RGGI: Cap and trade program already happening in the US. -Started in 2008. -States sell carbon allowances during quarterly auctions. -Proceeds invested in energy efficiency projects and renewable energy. -Virginia planning to join, NJ to re-join.

Sea ice projections:

Sea ice went down faster than predicted by any of the models (also from 2000-2010).

Recent WA legislative bills- passed on Earth Day 2019:

Senate Bill 5116: phase out use of fossil fuels in power generation by 2025. House bill 1112: phase out use of HFCs. Still to be voted on: -New energy standards for buildings and availability for electric vehicle charging in new buildings. -Efficiency standards for some appliances. -Clean fuels standard.

Building an ice sheet:

Snow falls. More snow falls, exerting pressure on the underlying snow. The partially deformed snow is called firn. Eventually, the snow is compressed enough to become ice. Thee ice has lots of bubbles trapped inside of it. The ice gets thicker and begins to flow under its own weight. Take a core near the middle to get information about precipitation, temperature and atmospheric composition in the past.

Myth: Albedo effect of solar panels causes global warming:

Solar panels are dark: do they affect planetary albedo? For putting dark panels on surface, will that increase amount of energy absorbed? -Wrong! The albedo change is small and results in a negligible amount of heating. This is not a problem. All the electricity in the world could be generated by solar panels covering an area of the black box below. -Total extra absorbed radiation if panels are above desert: 0.01 W/m2 (compare with 4 W/m2 for doubling CO2). -Solar panels can also be installed on dark roofs. Those already have a low albedo.

Transportation emissions in WA:

Because we have clean electricity, a large percentage of WA's GHG emissions are from transportation (45%). Huge improvements in our footprint can be made by switching cars to hybrid/electric cars.

Basic strategy:

Block enough sunlight to cancel radiative forcing due to increasing CO2. Giant space-based sunshade placed in outer space at a point where the gravitational field from the earth cancels that from the sun. Mirrors orbiting the earth to reflect sunlight. Make more clouds or more reflective clouds. place/shot tiny particles in the stratosphere that reflect sunlight.

Geoengineering: other ideas:

Block warm water from reaching Greenland/Antarctica. "Enhanced alkalization" of the ocean: pumping lime into the ocean. Increase the albedo of the desert by putting mirrors out. Put a blanket on a glacier.

Lewis Fry Richardson:

British mathematician, physicist, atmospheric scientist. Scientific career very influenced by his Quaker beliefs (pacifism). Felt that his work could bring peace to earth. Made the first numerical weather prediction in 1922. Also had a dream of the future of weather prediction.

What drives the Ice Age cycles?

Solar radiation in the Northern hemisphere summer is key for growth/melt of ice sheets. -It's always cold enough for snow in the winter at high latitudes, so winter temperature don't matter. -But a colder summer means snow doesn't melt and can accumulate. -Less sunlight in the summer means colder summers and expansion of high latitude ice sheets and vice versa. -If there's more sunlight, it can melt these away. -The small changes in the amount of radiation that the Northern Hemisphere experiences in the summertime are the forcings that kick of a series of feedbacks (including ice-albedo and CO2 feedbacks) that push us into or pull us out of an ice age.

What are the goals??

Stabilize emissions - is stabilizing emissions enough? -No. Flattening out CO2 emissions still leads to large increases in CO2 concentrations. --Imagining blowing air into a balloon: you have to stop blowing into it to stop it from getting bigger. (the real system is less extreme because the ocean can take up a small amount of emissions). -Flat emissions lead to concentrations that increase.

Court rules 5-4 in favor of the states

States could be injured by EPAs decision "The harms associated with climate change are serious and well-recognized" The 1971 Clean Air Act gave the EPA authority to regulate greenhouse gases The EPA must consider its decision not to regulate them

Little ice age (1400-1800 AD):

Temperatures in some parts of the world were colder (europe, North Atlantic). There is evidence of a lot of snowy wintery scenes in Europe during this time. IPCC report from 1990: Note that there are no numbers on the temperature scales. People didn't have a good idea of temperature and spatial scales. We have learned a lot about paleoclimate in the intervening years. Proxy records suggest that the little ice age and medieval warm period were more localized events. I.e: some parts of the world were warmer during the little ice age. Even though this was a time of relative quiet, these swings in temp affected agriculture and ecosystems a lot.

In 2003, the EPA made two determinations

The EPA lacked authority under the Clean Air Act to regulate carbon dioxide and other greenhouse gases Even if the EPA did have such authority, it would decline to exercise it This determination was challenged and brought to the Supreme Court bu 15 states including MA, CA and WA

Obliquity:

The tilt of Earth's axis changes between 22.1 and 24.5 degrees (currently 23.5) 40,000 year cycle of steeper and less steep, more and less tilted. When the axis is strongly tilted, the seasons become more exaggerated- warmer summers and colder winters.

Electricity numbers:

Watt is a unit of power- rate of energy transfer. 100 watts: relatively bright incandescent light bulb (the non-efficient kind). 1000 Watts: average household demand (averaged over the day). 1 MW= 1 million Watts: average wind turbine has capacity of 2-3 MW (powers 1500 households for a year). 1 GW= 1 billion Watts (1,000 MW): average coal/nuclear power plant (powers 1 million households for a year).

Climate engineering is not necessary:

We have the technology and innovation (but not the commitment of government incentives) to halt the increase emissions of CO2, reasonably fast and even reduce emissions greatly. However, progress has been (still is) too slow to stem the tide: -Lack of public resolve. -Lack of leadership and commitment in business and government.

Little bits of data from the past, stitched together:

We want information beyond where the data was collected.

Problems with dimming the skies:

We would have to do it forever. -If somehow we weren't able to continue the scheme, Earth would experience very rapid warming. --Estimates suggest 2-4 C warming within 10 years. -Even after emissions go to zero (once we run out of fossil fuels) we'll have o continue to do this until CO2 returned to a safe level (1000 years?).

So what can we do about it?

We'll discuss ways to take out CO2 out of the atmosphere later. By "scrubbing" from the air chemically, or by promoting photosynthesis. Later we'll also discuss geoengineering solutions to cool the Earth even if CO2 levels are high. By blocking out the Sun. But let's first discuss how to emit less Co2. It's possible.

But science can be wrong/debatable:

With any study, there is some interpretation of results, which often reasonable people can disagree with. Common missteps: -"Correlation is not causation". Just because two things are happening together doesn't mean one causes the other. -Apparent trends that don't have a physical justification. Another informal rule: don't claim your study says more than it actually does, -Not always followed.

Projected world population

World population is rising rapidly -Historically, this is a major reason for our growing influence on the environment -Especially rising in developing nations -If developing countries gain significant affluence, they can add to emissions tremendously

Remember:

the warming itself is often not a problem. It is the impacts that matter. For example. Sea level rise, droughts, floods, food production, species loss, etc

Temperature through time:

Deep (distant) past was mostly warmer than today.

Milankovitch cycles:

Developed a mathematical theory connecting the radiation received by Earth from the sun to the ice ages (and he did it by hand)

Summary: climate models:

Differ from weather models because the initial conditions are mostly unimportant. Only their statistics are relevant. Use the equations of fluid motion and heating from radiation, condensation, etc. Have parameterizations of small scale processes involving clouds, plants processing moisture. Are strenuously tested and have been shown to give reliable forecasts. Are not perfect.

Paleoclimate: proxies: proxy

"Agency of one who acts instead of another". From latin, similar to the word proctor. In terms of climate, proxy data are collected from natural recorders for climate variability in contrast to thermometers, rain gages, satellite gravity information or other direct measurements. Tell us about temperature, precipitation, wind, etc. through indicators left in the environmental record.

What kind of context has paleoclimate given us?

Times have been much warmer and much cooler. Seen that there is a lot of variability in time and space.

Paleocene-Eocene Thermal Maximum ((PETM) lasted ~200,000 years):

55 million years ago there was a quick jump in temperature Same time as pockmarks formed on the ocean floor, suggesting release of methane hydrate (crystals that hold methane in their molecular structure). Ocean was warming and released all of these hydrates all at once, which caused this spike in temperature.

Tactic #1: reframe the debate:

A few CEI-sponsored ads aired in 14 US cities in May 2006.

Global temperature trends:

Around 0.8 C of warming since 1880.

Previous warm climates cretaceous

During the cretaceous period (at the end of the Mesozoic era) sea levels were 200 m higher than today. The entire middle of N. America was a giant seaway. Lots of chalk deposits from shells in the inland seas.

How would the ice ever melt?

Extremely high greenhouse gas concentrations would be required to deglaciate.

Future of climate models:

Higher resolution. -Or coupling to regional climate models. Ensembles (more runs) because it is less expensive. Decadal predictions. Model intercomparisons.

Climate models:

Predicting the climate using computers. -Important tool for understanding possible future climates.

Control on CO2 over time:

Release by volcanoes is a relatively efficient way of getting CO2 into the atmosphere. -Remember this is small as compared to current human emissions. -Volcanoes are very important over hundred thousand year timescales. When we're considering long timescales, have to think about how CO2 is removed as well. How does CO2 get removed from the atmosphere over long times? -Land masses are key in a process called chemical weathering.

Snowball Earth

Steve warren (UW atmos sci/earth and space sciences) studies snowball earth

How did life survive?

We know life existed before snowball events How would it have survived the ice-covered surface And actually, after the snowball earth events ended, the Cambrian explosion happened (multicellular creatures evolved). We went from single celled life to multicellular creatures.

Two questions to consider and discuss:

Why do you think that there is a lot of debate about the cause or effects of global warming? If it is accepted that global warming is happening, why is it still difficult to take action on it?

in warmer climates

the ice melts, and adds the stored up light isotopes back into the ocean. Also, more of the precipitation can make it to fall out over the ice sheets and the heavy oxygen isotopes get trapped in the ice. -Cloud above ice has more heavy isotopes. -Evaporation favors light.

Typical arguments of the skeptics:

"It isn't warming", or the "data aren't good enough to say it is warming". -Not many in this camp anymore. -Decadal global average has remained higher than any in the history of weather observing. "The warming is real, but it is natural variability". -Natural variability does exists! --Natural climate variability superimposed upon forced climate change will result in a range of possible future trends for surface air temperature and precipitation over the next 50 years- Deser and Phillips, 2013. -Natural variability has been exceeded" --"Our results show that it is extremely likely that at least 74% (+- 12%) of the observed warming since 1950 was caused by radiative forcings, and less than 26% (+- 12%) by unforced internal variability". - Huber and Knutti, 2011. "The theory is flawed: there is no link between human activity and carbon dioxide increase in the atmosphere/warming", -Remember the greenhouse effect we talked about at the beginning of the quarter? GHG absorb longwave radiation, and re-emit in all directions. -Otherwise, Earth would be really cold. -If we add more CO2 to the atmosphere, we increase the proportion of greenhouse gases. "The models are uncertain, so we don't have to act". -Models are vigorously tested to ensure that they can capture what has already been observed (hindcasting). -The models that have been running for a while have done a good job of capturing the climate system (see modeling lecture). -Also... what level of uncertainty is tolerable for planning purposes? "But it's cold outside!" -Don't confuse the weather with long-term climate trends- need to look over a longer time period. "The projected changes are so small that it doesn't matter" or "it's not that bad". -Increased warming will affect agricultural yields in the tropics and sub-tropics. -Increased risk of heat waves. -Changes to animal habitat. -Ocean acidification. -Sea level rise + storm surges. -Kicking off feedbacks (e.g ice-albedo, releasing methane hydrates). "Too expensive to solve" -* "the future warming will happen and the projected changes will have large impacts but it will be cheaper to clean it up in the future than do something now". --A popular argument amongst skeptics (especially those who fall into the category "have a lot to lose if we do something now"). --A 2015 survey from Institute for Policy Integrity (NYU). --Asked economists with climate expertise when asked under what circumstances the USA should reduce its emissions. ---77% say regardless of the actions other countries have taken thus far.

Burying carbon in soils:

"Terra preta" ("black earth") in the Amazon basin has tons of old carbon in it. Created by humans between 450 BC and 950 AD. Adding charcoal to soil can keep carbon there for thousands of years. Extremely high quality soil too.

Tactic #2: Talk up certainty:

"Victory will be achieved when average citizens 'understand' (recognize) uncertainties in climate change". -From leaked internal memo by the American Petroleum Institute, 1998. Leaked memo by political strategist Frank Luntz: -"Voters believe that there is no consensus on global warming within the scientific community... therefore you need to continue to make the lack of scientific certainty a primary issue". I think talking about uncertainty should be encouraged. However think tanks have spread false doubt about even the most certain aspects of the science. This technique has worked successfully for many year: -Cigarette smoking. -Ozone depletion. -Strategic defense initiative. -Acid rain. Many famous global warming skeptics are the same people who argue about smoking, ozone, etc in the past.

Adaptation

(prevent harm; deal with symptoms): Alter human structures and practices in order to reduce the harmful effects of climate change for example: -Improved health care policies for heat-stress -Switch to heat-resistant crops -Build barriers to deal with sea-level rise

Cloud modification:

Controlled enhancement of the albedo and longevity of low level maritime clouds/ -Shoot a very fine spray of sea water into the air: makes cloud droplets smaller and thus more reflective of sunlight. -Works best in pristine ocean areas. Need thousands of ships. -Downside: clouds are the weakest link in understanding climate change.

How did life survive snowball earth?

Cracks in the ice? Maybe there was still liquid water underneath. Refuges of open water? Hydrothermal vents? Maybe heat from the internal part of the earth was heating the animals up.

Stratospheric sulfur injections:

Designed to imitate volcano eruptions. Inject a sulfate aerosol precursor (such as sulfur dioxide) into the stratosphere that then forms sulfuric acid solutions and eventually small particles. These aerosols increase earth's albedo by reflecting solar radiation back to space (direct effect). When injected really high up and if the particles remain small, they take a long time to fall out (months). Cheap compared to some estimates of mitigation costs (10-20 billion).

"Merchants of doubt", example: frederick Seitz:

Distinguished physicist. President of national academy, Rockefeller University. In 1979, became director of medical research for R.J Reynolds to confound link between tobacco and cancer. -Specific goal was to create reasonable doubt for court cases. Wrote the "Oregon Petition" letter asking scientists to state disagreement with Kyoto protocol.

Positive role of skeptics?

Do skeptics serve any positive role? Skepticism is good in science right? -When constructive, skepticism is always beneficial. -Usually skeptic tactics are just to criticize. Examples of skeptics making positive contributions: -Anthony Watts and followers have identified improperly positioned temperature stations. -Dick Lindzen has proposed testable hypotheses about clouds and global warming.

Why did I-1631 fail?

Dolsak (UW SMEA) and Prakash (UW center for Envt Politics). -Washingtonians (perhaps most americans) do not like new taxes, especially when they perceive benefits from the tax increase going to froups outside of their community. I-732 was revenue neutral. -Designed to return tax revenues back to citizens. -Not supported by several big envt groups (seen as too small). I-1631 was revenue positive. -Would have generated money, but would not have gone back as refunds to citizens, instead would have gone to projects like mass transit. -Dolsak and Prakash note that there was discontent around accountability for the funds that would be raised by the tax. -Was not seen as providing visible benefits to WA families. Initiative 1631's demise might have had something to do with the connection between taxing carbon and more immediate fears about one's health or one's job becomes obscured.

Renewable energy wind power: why does the wind blow?

Earth's surface is heated unevenly. Air moves from regions of high (cold air sinking) to low (warm air rising) pressure → produces wind. Warm: low pressure. Cool: high pressure. As air moves from high to low pressure, from air sinking to air rising, wind blows.

Chaos:

Ed Lorenz was running a computer model and put in slightly different inputs. -He found the predictions were similar for a while but then wildly diverged to different solutions. Chaos: when small changes make a big and unpredictable difference. The butterfly effect: "Does the flap of a butterfly's winds in Brazil set off a tornado in Texas?" [Lorenz, 1972]. -Weather forecasts depend very sensitively on the initial observations. -We can't observe every butterfly, so weather forecasts can't predict the exact path/strength of storms after 2 weeks. In contrast, climate models are all about modeling seasons.

Biofuels:

Effort needed by 2055 for 1 wedge: -2 billion 60 mpge cars running on biofuels instead of gasoline and diesel. -To produce these biofuels: 250 million hectares of high-yield (15 t/ha) crops, one sixth of world cropland. Challenge: to find ecologically responsible ways to grow biomass for power and fuel on hundreds of millions of hectares.

Efficient use of fuel:

Effort needed by 2055 for 1 wedge: -Decrease the number of miles driven per car: 5,000 instead of 10,000 miles per year. Effort needed by 2055 for 1 more wedge: -Double fuel efficiency of cars: 60 mpg instead of 30 mpg.

Fuel switching:

Effort needed by 2055 for 1 wedge: -Substitute 1400 natural gas electric plants for an equal number of coal-fired facilities. Natural gas is a lot better. -One wedge requires an amount of natural gas equal to that used for all purposes 2004.

Efficient use of electricity:

Effort needed by 2055 for 1 wedge: -Use best efficiency practices in all residential and commercial buildings. -25-50% reduction in expected 2055 electricity use in commercial and residential buildings. -Changing all light bulbs to CFL would be ⅓ of a wedge.

Conservation tillage:

Effort needed by 2055 for 1 wedge: -Use conservation tillage on all cropland (1600 Mha). -Leaves at least 30% of crop residue on the surface. -Stores more carbon within the soil. -Conservation tillage is currently practiced on less than 10% of global cropland (and 40% of US cropland).

Deforestation:

Effort needed by 2055 for 1 wedge: Eliminate all tropical deforestation.

Reforestation:

Effort needed by 2055 for 1 wedge: Plant new forests over an area the size of the continental US.

Efficient generation of electricity:

Effort needed by 2055 for 1 wedge: -Improve the efficiency of coal power plants from 40% to 60%, and double efficiency from which we take fossil fuels from the ground.

The Wedge strategy: the options: Wind electricity:

Effort needed by 2055 for 1 wedge: one million 2-MW windmills displacing coal power. In 2004 we had about 50,000 MW (1/40 of this). By the end of 2018, capacity had increased to 539,000 MW. More than ¼ of a wedge achieved in less than 15 years.

Pholtovoltaic (solar) power:

Effort needed by 2055 for one wedge: -2000 GW peak (requires 500X increase compared to 2004 capacity of 3.7 GW). -2 million hectares (about 12% the size of Washington): roofs can be used though. In 2017, capacity was 398 GW. Increase of >100 times from 2004. Now we only need a 5X increase for a wedge.

Carbon capture and storage:

Effort needed for 1 wedge by 2055: -Capture and store emissions from 800 coal plants. Effort needed for 1 wedge each by 2055: -Capture and store emissions from 1600 natural gas plants. As of 2018, 18 commercial-scale storage projects in operation. Instead of releasing CO2 into the atmosphere, store it underground

Carbon tax

Emitting carbon incurs a price charged as a tax Governments have experience with taxing (less experience for cap and trade) Monitoring, assessment and accountability are key to program success (again)

Global Climate Model (GCM)

Equations of fluid motion on a rotating sphere. Equations put simple physics principles in mathematical form. -Mass is neither created nor destroyed. -heating/cooling changes temperature. -Forces change momentum. Fluid motion on the sphere: atmospheric circulation looks like fluid motion from the global perspective. Apply the equations to physical processes within systems that determine climate. -Atmosphere - all GCMs. all early climate models start by modeling the atmosphere. -Can be coupled to physical models of the: --Ocean. --Biosphere (plants). --Cryosphere (sea ice, ice sheet). -If the coupled model includes the flow of carbon including the biological and chemical processes (not just physical), it is called an Earth System model. --Includes interactions between physical climate and the biological and chemical constituents of the ocean and atmosphere. Track changes to these systems over time as they respond to some forcing, for example. -Adding carbon dioxide to the atmosphere. -Changing the tilt of the Earth's axis.

Biofuel use today:

Ethanol makes up roughly 10% of US fuel usage. E10 is gasoline with 10% ethanol content by volume. E15 (15% ethanol) can be run in vehicles made in 2001 or later, and is available in some states. E85 is 85% ethanol and 15% gasoline, and it is mostly sold in the Midwest. Requires "flex-fuel" vehicle (because it is harder to start E85 in cold).

Why do people believe what they do?

Extremists: come on both sides of the issue: -Often potential people with things to lose with singular priorities (direct financial interests, localized/immediate interests). --Example: coal companies that fear that their industry will become less attractive. -People with priorities not directly related to human welfare, socially or economically. --Example: those that think the world will end soon. -People with political or ethical bents that are at odds with mitigation of emissions. --Example: full free-market organizations and their followers. Extremists are almost always motivated by issues not related to the science.

Evidence of snowball earth:

Features on the tropical landscape that could have only been left by glaciers. Dropstones in the sediment. Glacial striations. During snowball earth, volcanic activity injected CO2 into the atmosphere. With the land and oceans covered by ice. There was no chemical weathering to remove CO2 from the atmosphere so it accumulated and increased greenhouse effect.

Promote photosynthesis by fertilizing oceans:

Fertilize the ocean with iron (a limiting nutrient) to promote photosynthesis and thus remove CO2 from the atmosphere. Downsides: -Studies show after the phytoplankton bloom, most carbon goes right back into the atmosphere. -Major disruption to the base of the marine food chain.

Richardson's dream: the forecast factory:

Filled with employees ("computers") doing calculations. Richardson's dream in 1922 of a global forecasting system. He estimates 64,000 "computers" (people) would be necessary to forecast over the globe.

Failure or success?

First prediction was hugely hugely wrong. Richardson himself realized that noisy wind data was likely the problem. -He suggested 5 different filtering methods to fix this. Obviously he couldn't try this experiment again . -But we can reproduce the results using today's computers.

The predicament:

First the bad news: -What has already been emitted? --And what does it mean for future climate? -What is the goal? --And what does the world look like even if we stay beneath that goal? Then the good news: -What approaches can be used to reach the goal? --The wedge strategy. -We can fix it: --And many of the changes that are used to help fix the climate problem are beneficial in other ways.

Role of the Media:

For many years, the media presented global warming as a "he said, she said" style debate. -Equal time given to someone from the skeptical side, despite their small numbers. -And often those skeptics wouldn't agree with each other at all if they debated. --Some would say Earth isn't warming, others would say warming is due to the Sun, some would say warming is good, etc.

Why should we regulate?

Harm from global warming is not the same for everyone -Inequities result from both the --Regional variability of climate responses/ vulnerability and --Wealth of the region, which affects their ability to adapt For these two reasons, adaptation costs will not be equal for all countries, regions, states, countries or cities "It turns out that the areas that are preferentially harmed by warming are also areas that tend to be poorer on the whole" "And that is just because of where they happen to be and what their climate already is" Those who are emitting the most GHG are less vulnerable to climate change

Renewable energy hydropower:

Harnesses the energy of water that is moving under the force of gravity. Historically used to run textile and saw mills. Would churn a wheel and stone inside of a textile mill would break things down. Today used primarily to generate electricity. Harness energy up high, and it turns a turbine to produce electricity. Evaporation does the work of lifting the water to higher altitudes. Hydropower takes the kinetic energy of the water flowing downhill and transforms it into mechanical or electrical energy. Water will fall down as precipitation. Store water behind a dam → release as needed → flows downhill through turbine → generates electricity. China uses the most hydropower, then Canada then Brazil, then USA.

Uncertainty in Climate sensitivity:

High sensitivity climates are hard to rule out. From 6,000 doubled CO2 simulations, randomly changing climate model parameters. Very high temperature changes (E.g: 8C) are unlikely, but hard to rule out (on the other hand, small temperature changes like 1C are essentially impossible).

Climate modeling clouds continued:

Highest resolution models can capture more details of cloud structures. This will be the resolution of the future. -A: infrared image from MTSAT satellite. -B: Outgoing longwave radiation from a model with 3.5 km grid spacing.

The science police: peer review:

How are the rules enforced? Any scientific paper is "peer reviewed". -Other scientists read it to make sure it follows good scientific practices, that arguments make sense, etc. -Authors get a chance to respond to reviewers, add info, modify conclusions, etc. -If the reviewers aren't convinced, the editor can reject the paper. -Peer review is pretty tough. -A good system, but not perfect.

Epica ice core record from the EPICA ice core in East Antarctica:

Interglacial periods are warmer Glacial periods are cooler. The temperatures are so cold because we are in Antarctica. Remember, though: CO2 is well mixed, so we can assume that these are good estimates for global CO2. What can you say about the relationship between temperature and CO2 concentration levels over time? They are following each other and are directly related. Look at the last 4-5 interglacial periods. Approximately how far apart are they in time? 100,000 years apart approximately. Huge temperature changes in ice ages: up to 10 C in Antarctica, 5 C globally. Carbon dioxide concentration (measured in air bubbles trapped in ice) show a remarkable correlation with temperature (recorded in the isotopic signature of the ice itself). For the past 2.5 million years, we have been going in and out of ice ages. Can extend records back to 5 million years ago with ocean sediment data.

Do wedge strategies get used up?

Is the second wedge easier or harder to achieve than the first? Are the first million two-megawatt wind turbines more expensive or cheaper than the second million two-megawatt wind turbines? -The first million will be built at the more favorable sites. -But the second million will benefit from the learning acquired building the first million. The question generalizes to almost all the wedge strategies: -Geological storage capacity for CO2, land for biomass, river valleys for hydropower, uranium ore for nuclear power, semiconductor materials for photovoltaic collectors.

Will climate engineering happen?

It is incredibly easy and (in the short term) inexpensive compared with reducing emissions and transitioning to a non-carbon emission economy. -Cost is maybe only 10B/yr compared to 200B/yr to reduce carbon emissions (lots of uncertainty in these estimates though). -Cost is less than 0.1 GDP for US, less than 2% for about 30 countries. Players who are currently influential and have a lot to lose if greenhouse gas emissions are reduced (oil companies, libertarians) don't lose from climate engineering. Whoever holds the contract for the solution has huge profits guaranteed for a millennium

Alternative ways countries can get credit to meet their targets:

Joint implementation: -Allows countries to collaborate in projects that reduce emissions Clean development mechanism: -Allows developed countries to get credit for projects that reduce emissions in developing countries (this aids the goal of technology transfer, essential to long-term reductions by the entire world) Emissions trading: -Allows developed countries to purchase credits from -Other developed countries. Creates a market in "carbon credits" Developing countries have no mandatory requirements. If they reduce emissions anyway, they may sell credit

Some downsides of the stratospheric aerosol sunshade solution:

Large uncertainty to how much/how often you have to inject sulfur into the stratosphere to cancel warming effect of increased CO2. Sulfate aerosols could heat the lower stratosphere. Sulfur chemicals in the stratosphere may destroy ozone in the protective ozone layer. So we might try nanotech particles (may be difficult or impossible to remove).

Using climate models to build understanding:

Often climate models are thought of as forecast told (what's the climate going to be like in 50 years?). Models are equally useful for developing understanding though. -We only have one Earth to observe. -We're only limited by our creativity in making our own computer worlds.

Passive solar home design:

Orient buildings to receive max sun. Use building materials that absorb sun.

Local Policies: Mayors Agreement:

Over 50 mayors gathered in Chicago in 2017. Signed agreement to reduce carbon emissions in their cities. -Hitting Paris Agreement targets. Has 407 US cities, representing 70 million Americans.

The predicament IPCC RCP scenarios:

Over the next two decades, global temperature increase is projected to be between 0.5F and 1.3F (0.3C-0.7C) (medium confidence). This range is primarily due to uncertainties in natural sources of variability that affect short-term trends. In some regions, this means that the trend may not be distinguishable from natural variability (high confidence). Beyond the next few decades, the magnitude of climate change depends primarily on: -Cumulative emissions of greenhouse gases and aerosols. -The sensitivity of the climate system to those emissions. -There is a lot of uncertainty because we are not sure how sensitive the climate is and how much CO2 we will emit.

Paleoclimate: what sets the climate over Earth's history?

Paleo: from the Ancient Greek for "ancient". Why may it be useful to understand the climate of the past. To get an analogue for how greenhouse gases interacted with the climate system. To better constrain feedbacks. The analogy is less than perfect. Why? Different "starting point". Different forcings (and different rate of forcing). Imperfect knowledge of the conditions of the past.

Summary: alternative energies:

Produce energy without generating CO2 (or less CO2). Many are renewable (significant exception is nuclear power). Many types are growing fast (especially solar and wind). They each have pros and cons to varying degrees.

Renewable energy hydropower pros and cons:

Pros: -No emissions of pollutants or greenhouse gases. -Relatively cheap. -Domestically sourced, don't need to have trading issues. -Flexible in meeting fluctuating demands (when to release from the dam). Can release from the dam at any time as needed. Cons: -Submerge forest, farmland communities to build reservoirs. -Alters ecosystems. --Fish migration interference. --Seasonal variability in stream flow is taken away. --Sediment distribution disturbed.

Renewable energy pros and cons:

Pros: -Produces no greenhouse gases after panel is installed. -Unlimited. -Long lasting (low maintenance cost). -Peak production in-sync with demand (we don't need as much power at night). -Decentralized production, people can put it in rural areas and produce their own energy without having to pay anyone for it. Cons: -Expensive now. -High upfront cost. -Somewhat limited by location (deserts and gold mines for solar energy, but storing/transporting the power is expensive/inefficient).

Wind power pros and cons:

Pros: -Produces no greenhouse gases after windmill is constructed. -Decentralized production. -Moderately priced in the long term compared to fossil fuel. -Can use land underneath. -Tech has improved greatly recently. Cons: -Intermittent. -Not available everywhere. -Obstructs views/noise. -Hazards to birds? (probably not if placed away from migration zones). -Requires large area.

Nuclear power pros and cons:

Pros: -Produces no greenhouse gases. -Available 24 hrs/day. Cons: -Expensive to build facilities. -Storage of extremely hazardous radioactive wastes. -Requires lots of water. Water gets heated and put back into streams. -Relationship to weapons (concerns about creating plutonium or a terrorist attack).

Another goal: minimize temperature increase:

Remember: some warming is locked in even if we keep CO2 concentration exactly at today's level. Temperature still increase by 0.6C because the ocean takes time to warm. Historically, the goal has been to stabilize global temperatures to be no more than 2C over pre industrial levels (average of 861-1880). Cumulative global CO2 emissions must stay below about 800 GtC in order to provide a two-thirds likelihood of preventing 3.6F (2C) of warming. Given estimated cumulative emissions since 1870, no more than approximately 230 GtC may be emitted in the future to remain under this temperature threshold. Assuming the RCP 4.5 scenario, this cumulative carbon threshold would be exceeded in approximately two decades (high confidence). We've already warmed about 1C. Some believe that 1.5C is a better goal than 2C. But the effects of a warmer world would still be felt with there targets. 1.5C- sea ice will remain during most summers/ 14% of world population will be exposed to heat waves like 2007 Europe/ +350 million people will be exposed to severe drought/ 31-69 million people exposed to flooding from sea level rise in 2100 (without adaptation). 2C- ice-free summers are 10x more likely/ 37% of world population will be exposed to heat waves like 2007 Europe/ +411 million people will be exposed to severe drought/ 32-80 million people exposed to flooding from sea level rise in 2100 (without adaptation).

Renewable vs non renewable energy:

Renewable energy is constantly replenished. Most sources of renewable energy are ultimately driven by the sun: -Solar power, yes, but also -Evaporation → moves water to higher elevation → hydropower. -Sun → differential heating of earth's surface → drives wind. -Sun → allows plants to grow → biofuel and biomass. Renewable energy does not mean that there are no carbon emissions. -For example, burning biomass releases carbon to the atmosphere. -But several renewable energy sources do not release CO2 to the atmosphere. 1.5 hours of sunlight striking Earth's surface contains more energy than what is consumed by all humans in an entire year. Why hasn't this been our primary source of energy in the past century? Unfamiliar/new technology (risk, investment capital). -Scale of production is small → cost of production is high. Externalized costs (govt. Subsidizes fossil fuels, cost of envt./health problems) are not included in fossil fuel pricing.

Green new deal

Resolution proposed by Rep Alexandria Ocasio-Cortez and Se. Ed Markey Aims to make remake the US economy and eliminate all US Carbon Emissions Non-binding Not yet up for a vote in either the House or the Senate -But has gotten a lot of attention from both sides of the floor -A vote could happen soon, but would not pass in the Senate Getting there will also cost A LOT of money (trillions (?)) -Would require expansive new taxes and federal programs -It is unlikely to be accomplished within the 10-year time frame that supporters say is necessary

COP 21: Paris, 2015

Resulted in Paris Agreement -Aims to keep temperature rise below 2C, endeavors to keep it below 1.5C -Each country submits their own pledge for cutting emissions --Pledges reviewed every 5 years, to scale up efforts -Developed countries provide financial assistance to developed countries for adaptation and mitigation through the Green Climate Fund --$100 billion per year by 2020 -Not legally binding Went into effect october 5, 2016 -Enough parties ratifies USA dropped out on June1, 2017 Agreement stays in effect even without our participation Some countries have taken aggressive steps -Ex: 9 countries to ban gasoline cars by 2040 Green climate fund: -Had some procedural difficulties in 2018 -Countries are still contributing though Pledges of the countries are not currently sufficient to assure <2C warming -And uncertainty in climate sensitivity is not often talked about in these discussions The "Yellow Vest" protests (Dec 2018) over a fuel tax hike in France are a reminder that countries need to be careful about where carbon emission cuts are coming from and how they are rolled out

Earth Summit, Rio de Janeiro 1992

Rio declaration on environment and development Representatives of 160 nations met to discuss: -Resources needed for development, and -Long-term protection of the environment UNFCCC treaty -"The ultimate objective of this convention... is to achieve.... Stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system" -Behavior is encouraged, but nothing is binding Signed by all 160 nations, including the US SIgned by the George HW Bush, summer of 1992 Ratified by the required ⅔ of US senate, Fall 1992, giving the force of law within this country

IPAT equation for analyzing CO2 emissions

The IPAT equation is a widely used simplification of the factors causing environmental degradation I = P x A x T -I: total impact - CO2 emissions rate -P: population -A: affluence - per capita income -T: technology - emissions per unit of income

Precession of the equinox:

The change in orientation of the axis, which way is the Earth pointing when it is at closest approach to the sun or at furthest from the sun? 26,000 year cycle. Strengthens or weakens the effect of the other two variations.

Over thousands of years:

The most recent ice age ended about 11,500 years ago. Then came a drastic warm-up. Without anthropogenic climate change would expect another ice age in several thousand years.

During interglacial warm periods:

The water in the ocean has a relatively high amount of light oxygen. The snowfall deposited in the ice sheets has a relatively high amount of heavy oxygen.

Climate forecasts

This chaotic limit to weather prediction doesn't affect climate forecasts. Chaotic limit doesn't exist. -It all averages out after a few months of storms. Climate forecasts: -Summer is hotter than winter. -After a strong volcano blows up, the Earth will cool. -The Earth will be hotter with more greenhouse gases. -Shifts in weather patterns when El Nino is present. Climate forecasting: Getting the average location/intensity of storms

Other potential problem with wind power: aesthetics:

This proposed wind farm on cape cod, MA was highly controversial due to concerns about views

PETM

This tiny horse (sifrhippus) shrank even smaller as temperatures rose. -Smaller animals can shed heat more easily, rather than being big and needing to sweat a lot, these animals shed heat easily Tapir teeth and crocodiles. Arctic ocean sea-surface temperatures as high as 23C 56 million years ago.

There is a current discussion about shifting to open source code, data and publications.

This would allow studies to be reproduced more easily and would allow for ease in checking for errors.

The Holocene:

Time since last ice age (last 15k year). Coming out of the last ice age was a bumpy ride. Post glacial sea level rise. Younger dryas (13-11.5 kyr ago). Abrupt climate change- regression back to a cold climate, and then a quick leap out, back to warm climate. Causes? -Big freshwater flux to the ocean from melting ice sheets. -Ongoing research topic. Ecosystem chaos happening at this time because it kept going from cold to warm. Sea level went up, all the ice on the land started to melt and went to the oceans, and there was a big meltwater pulse, and then another, and then sea level rise stopped rising so much. Between 10,000 and 6,000 years ago, the Sahara was covered by a dense network of rivers, lakes and inland details. Hippos lived there. Fish migrated through the area.

Why is there disinformation?

Traditionally, think tanks build knowledge, formulate policy scenarios and evaluate their implications based on scientific knowledge. Examples: -Universities. -National academy of sciences.

How to regulate?

Tragedy of the commons -Originally posed with the example of over-gazing on shared land -Optimizing behavior of individuals can produce a bad outcome for everyone -Consumer choice tends to not work so well in these situations --Most economists agree that some regulation is necessary in these situations

Paleoclimate: proxies: biological proxy data

Tree rings Pollen Corals Fossils

Paleoclimate

What determines the climate on really long timescales How do we know about the climate of the past? Extreme climates of the past -Cold cold --Snowball earth events were the result of a runaway ice-albedo feedback --Because ice covered the land surface, there was no rock exposed for chemical weathering to remove CO2 from the atmosphere ---Also assume that the hydrological cycle was pretty weak --This allowed volcanically-sourced CO2 to build up in the atmosphere, causing an intense greenhouse effect, and finally melting the ice very rapidly -Hot hot --Hot climates probably emerged as a result of increased volcanic activity --CO2 concentrations were really high, so temperatures were really high too ---Also high sea levels, warm oceans, tropical ecosystems much farther north --We transitioned from these hot climates around 35 million years ago, as the continents moved to their current configurations, and weathering increased The Ice ages The last few thousand years

Paleoclimate:

What determines the climate on really long timescales? How do we know about the climate of the past? Extreme climates of the past Cold cold -Hot hot -The ice ages The last few thousand years

Regulation of Grenhouse gases via EPA

What's happening with global warming regulation in the US? Cap and trade has been a non-starter in Congress for a while The Obama Environmental Protection Agency (EPA) took big steps in regulating greenhouse gases Scott Pruitt's and now Andrew Wheeler's EPA has been rolling these back

Chemical weathering:

When rain/snow falls on silicate rocks, it reacts and takes CO2 out of the atmosphere. is a negative feedback. When climate is hotter, it's easier for weathering to take CO2 out of the atmosphere. Likely key for stabilization of climate over millions of years. During Snowball Earth, volcanic activity injected CO2 into atmosphere. With the land and oceans covered by ice, what would happen to the CO2 in the atmosphere? With the land covered by ice, there was no weathering to remove CO2 from the atmosphere, so it accumulated, and led to an increase in the Greenhouse effect. Eventually, the greenhouse effect became so strong that the ice began to melt, despite its high albedo. Once initiated, melting would proceed very rapidly as the albedo lowers. 1. Atmospheric carbon combines with water to form a weak acid that falls to the surface as rain 2. The acid dissolves rock and releases calcium ions to the ocean. 3. In the ocean,. These ions combine with others to form calcium carbonate and make shells. 4. When the organism in the shell dies, the shell sinks to the sea-floor. 5. Over time, layers of shells and sediment are cemented together, and turn into rock. 6. The carbon is therefore stored in stone.

How is wind power generated?

Wind blows past a turbine (like a propeller). Turbine is turned → energy. Power produced is proportional to the (wind velocity)^3. Wind turbines are mounted on towers to take advantage of higher speeds farther off the ground. Rotor blade up to 50m long. Each turbine can generate enough electricity to power 1400 homes.

Wind power main problem: intermittency:

Wind doesn't always blow: -Currently this isn't a huge problem because wind doesn't provide most of the electricity anywhere. -Having a grid with sufficiently large area can help ensure that the wind is blowing somewhere. -Solar power tends to be complementary to wind in midlatitudes (windier in winter, sunnier in summer).