Environmental Science 14

At the end of the 21st century, temperatures will be

1.8 to 4.0C higher than today's

Regional Greenhouse Gas Initiative (RGGI) (2007)

10 northeastern states, Set up a cap-and-trade program

Measuring ocean and atmospheric chemistry began in

1958

CO2 has increased from

280 ppm (1700s) to 389 ppm, The highest in 800,000 (possibly 20 million) years

Transportation

2nd largest source of U.S. greenhouse gases, Cars are extremely inefficient

Hourly air samples from Mauna Loa Observatory in Hawaii show that

Atmospheric CO2 concentrations have increased from 315 ppm to 389 ppm since 1958

Trapped bubbles in ice cores provide a timescale of

Atmospheric composition, greenhouse gas concentrations, temperature, snowfall, solar activity, Frequency of fires and volcanic eruptions

Why have CO2 levels risen so rapidly?

Burning fossil fuels transfers CO2 from underground deposits into the atmosphere , Deforestation contributes to rising atmospheric CO2

To reduce fossil fuel use

Conservation, efficiency, cleaner or renewable energy, Cogeneration, more efficient appliances

Climate change affects economics

Costs will outweigh benefits of climate change, It will widen the gap between rich and poor

Areas that will be most affected include

Densely populated, poor regions (e.g., Bangladesh), Storm-prone regions (e.g., Florida), Coastal cities (e.g., Houston), Areas with land subsidence (e.g., U.S. Gulf Coast), Pacific Islands will have to be evacuated

Responsibility for emissions now goes to the

EPA

The Regional Greenhouse Gas Initiative

Each state decides which polluting sources participate, Each state sets a cap on total CO2 emissions it allows, Each emissions source gets one permit for each ton it emits, up to the amount of the cap, Each state lowers its cap over time, Sources with too few permits must reduce emissions, buy permits from others, or pay for carbon offsets, Sources with too many permits may sell them, Any source emitting more than permitted will be penalized

Current and future trends and impacts

Evidence that climate has changed is everywhere, Fishermen in the Maldives, ranchers in Texas, homeowners in Florida, etc.

In December's 2011 meeting in Durban (South Africa)

Getting consensus among 200 nations will be difficult, Political steps are not enough to stop climate change

"Climategate"

In 2009, a hacker illegally broke into a university's computer in the U.K., Private e-mails seemed to show questionable behavior by a few scientists in using data, Climate deniers accused the entire scientific establishment of wrongdoing and conspiracy, Investigations showed no evidence of wrongdoing, Media accounts misrepresented the e-mail contents

If a model accurately reconstructs current climate

It may accurately predict future climate

To reduce emissions, should the government

Mandate change through laws and regulations, Impose no policies and hope for solutions, Give private entities incentives to reduce emissions?

Despite overwhelming evidence for climate change

Many in the U.S. deny what is happening, People debate if it is real and if humans are to blame, Think tanks and a few scientists question it, The news media present both sides, despite the evidence of climate change

Melting of snow and ice has severe effects

Mountaintop glaciers are disappearing

Organisms are adapted to their environments

Species will move toward the poles or up in elevation

Success will come from

Technology, Carbon trading markets, National, regional and local acts, Business efforts, Policy makers helping the private sector find solutions

The U.S. Global Change Research Program reported and predicted

Temperature increases (2.2 - 6.1C higher), Worse droughts and flooding, Decreased crop yields, Water shortages, Health problems and diseases, Higher sea levels, beach erosion, destroyed wetlands, Drought, fire, and pests will change forests, More grasslands and deserts, fewer forests, Undermined Alaskan buildings and roads

The European Union Emission Trading Scheme (2005)

The world's largest cap-and-trade program, Governments had allocated too many permits, Industries had little incentive to cut emissions, Permits lost 90% of their value, The EU is trying to fix these problems

The Kyoto Protocol tried to limit emissions

This treaty took effect in 2005, After Russia became the 127th nation to ratify it, The United States will not ratify the Kyoto Protocol, It requires industrialized nations to reduce emissions, But it does not require industrializing nations (China and India) to reduce theirs

The Mayors Climate Protection Agreement

Will meet or beat Kyoto's guidelines

U.N. Framework Convention on Climate Change

a plan to voluntarily reduce greenhouse gas emissions, To 1990 levels by 2000, This voluntary approach did not succeed, Signatory nations created a binding international treaty requiring emission reductions

Adaptation

accept that climate change is happening, Pursue strategies to minimize its impacts on us, Seawalls, coping with drought and less water, etc.

The ocean's thermohaline circulation system

affects regional climates, Moving warm tropical water north, etc., Greenland's melting ice sheet will affect this flow

Climate

an area's long-term atmospheric conditions, Temperature, precipitation, wind, humidity, etc.

Global warming

an increase in Earth's average temperature, Only one aspect of climate change

We are concerned with the

anthropogenic (human-caused) intensification of the greenhouse effect

Greenhouse gases

are not all equal, differ in their ability to warm the trophosphere and surface

Global warming and climate change

are not the same

Greenhouse gas concentrations

are rising, have always been in the atmosphere

Greenhouse gases

atmospheric gases that absorb infrared radiation, Water vapor, ozone, carbon dioxide, nitrous oxide, methane, halocarbons (chlorofluorocarbons [CFCs]), re-emit infrared energy

Ocean acidification

caused by increased CO2, Organisms can't build their exoskeletons

Soot (black carbon aerosols)

causes warming by absorbing solar energy

El Niño and La Niña events

change regional weather, Dry areas get wetter, while wet areas get dryer

Modeling is hard because

climate and feedback loops are so complex

Glaciation

cold temperatures and ice sheets

Climate models

combine data from atmospheric and ocean circulation and interactions, To simulate climate processes

We have increased the

concentration of these gases beyond what we have ever experienced

Temperatures

continue to increase, The future will be even hotter

Carbon dioxide

contributes most to the greenhouse effect, less potent, but far more abundant, than other gases, the major type of human-caused emissions

tropospheric aerosols

cool the atmosphere by reflecting the sun's rays

Negative forcing

cools the surface

Global climate change

describes modifications in Earth's climate, Temperature, precipitation, storm frequency

The 2009 House of Representatives' cap-and-trade system

did not pass the Senate, Industries would compete to reduce emissions for financial gain

Geoengineering

drastic, assertive steps to change Earth's climate, Suck carbon out of the air by planting trees, fertilizing the ocean with iron, Block sunlight with dust, seeding clouds, installing mirrors on land, on sea, and in space

Solutions to transportation

drive fuel-efficient, hybrid, or electric cars, Drive less and use public transportation, Live near your job, so you can bike or walk

The 2009 Copenhagen conference

ended in discord, China wouldn't allow international monitoring, Obama would not promise more than Congress had agreed to

Nitrous oxide

feedlots, chemical manufacturing plants, auto emissions, and synthetic nitrogen fertilizers, Risen 18% since 1750

Methane

fossil fuels, livestock, landfills, crops (rice), Levels have increased 2.5 times since 1750

Sulfate aerosols

from fossil fuel combustion may slow global warming, at least in the short term

Fee-and-dividend

funds from the carbon tax (fee) are passed to taxpayers as refunds (dividends)

Carbon tax

governments charge polluters a fee for each unit of greenhouse gases they emit, Polluters have a financial incentive to reduce emissions

Variation in solar energy (e.g., solar flares)

has not been great enough to change Earth's temperature

The Montreal Protocol

has reduced halocarbons (CFCs)

Earth's climate

has varied naturally through time, Today's is happening at an extremely rapid rate, due to human fossil fuel combustion and deforestation

Ozone levels

have risen 36% due to photochemical smog,

Health

heat waves and stress can cause death, Respiratory ailments, expansion of tropical diseases, Disease and sanitation problems from flooding, Drowning from storms

Ice caps, ice sheets, and glaciers

hold clues to Earth's climate history

Signatory nations have

increased emissions 7.9%

Forestry

increased fires, invasive species, Insect and disease outbreaks

Proxy indicators

indirect evidence that serve as substitutes for direct measurements of past climate

Radiative forcing

is 0.12 watts/m2 —less than any human causes

Nitrous oxide

is 298 times as potent as carbon dioxide

The U.S. federal government

is not acting, So state and local governments are

Permafrost (permanently frozen ground)

is thawing, Destabilizing soil, buildings, etc., and releasing methane

Climate change

is the fastest-developing area of environmental science

Aerosols

microscopic droplets and particles, They have either a warming or a cooling effect

Ocean circulation

ocean water exchanges heat with the atmosphere, Currents move energy from place to place

Ocean absorption

oceans hold 50 times more carbon than the atmosphere, Slows global warming but does not prevent it, As oceans warm, they absorb less CO2, accelerating warming

Carbon offset

payment to another entity to reduce the greenhouse emissions that one is unable to reduce oneself, The payment offsets one's own emissions

Milankovitch cycles

periodic changes in Earth's rotation and orbit around the sun, Alter the way solar radiation is distributed over Earth, modify patterns of atmospheric heating, triggering climate variation

Other indicators include

pollen preserved in sediment, tree rings, pack-rat middens, coral reefs

The Stern Review on the Economics of Climate Change

predicts it will cost 5-20% of GDP by 2200

Mitigation

pursue actions that reduce greenhouse gas emissions to lessen the severity of climate change, Energy efficiency, renewable energy, protecting soil, preventing deforestation

Volcanic eruptions

reduce sunlight reaching Earth's surface and cool the Earth

Forestry

reforest cleared land, preserve existing forests, Sustainable forestry practices

Carbon capture

removes CO2 from power plant emissions

The oceans

shape climate by storing and transporting heat and moisture

Weather

short-term conditions at localized sites

Climate change affects Agriculture

shortened growing seasons, decreased production, crops more susceptible to droughts, Increasing hunger in many developing nations

The Kyoto Protocol (1997)

signatory nations must reduce emissions of six greenhouse gases, To levels below those of 1990 (by 2008-2012)

Carbon sequestration (storage)

storing carbon underground (old oil deposits, salt mines, etc.), We can't store enough CO2 to make a difference

The IPCC's Fourth Assessment Report (2007)

summarized thousands of studies, It documented observed trends in- Surface temperature, precipitation patterns, snow and ice cover, sea levels, storm intensity, etc., It predicted future changes on wildlife, ecosystems, and human societies, It discussed strategies to pursue in response to climate change, The authors assigned statistical probabilities to its conclusions and released conservative estimates

Three factors influence Earth's climate

sun atmosphere oceans

Agriculture solutions

sustainable land management lets soil store more carbon, Reduce methane emissions from rice and cattle, Grow renewable biofuels

Direct measurements

tell us about the present

Storm surge

temporary, localized rise in sea level, Caused by the high tides and winds of storms

In 2007 the U.S. Supreme Court ruled that

the EPA could regulate CO2 as a pollutant

Carbon footprint

the amount of carbon we are responsible for emitting

Radiative forcing

the amount of change in thermal energy that a given factor causes

Greenhouse effect

the energy that travels downward warms the atmosphere and the planet's surface

Electrical generation

the largest source of U.S. CO2, 70% of electricity is from fossil fuels, especially coal

Water vapor

the most abundant greenhouse gas, Contributes most to the natural greenhouse effect, But concentrations have not changed

Global warming potential

the relative ability of one molecule of a greenhouse gas to contribute to warming, Expressed in relation to carbon dioxide (potential = 1)

Solar output

the sun varies in the radiation it emits

As Earth's surface absorbs solar radiation

the surface temperature increases and emits infrared radiation

Waste management

treating wastewater, Generating electricity by incinerating waste, Recovering methane from landfills, Individuals can recycle, compost, reduce, or reuse goods

Understanding climate change requires

understanding how our planet's climate works

Greenhouse gases

warm the lower atmosphere

Positive forcing

warms the surface

The Intergovernmental Panel on Climate Change (IPCC)

was established in 1988, Composed of hundreds of international scientists and government representatives

Cancun's 2010 meeting

was more productive, Developed nations will help developing nations with technology and with mitigation and adaptation, Nations that reduce deforestation will be rewarded, China and India will reduce emissions (in principle)

Carbon-neutrality

where no net carbon is emitted

Cap-and-trade programs

will be self-sustaining, Permit prices fluctuate in the market

California's Global Warming Solutions Act

will cut emissions 25% by 2020

Rising sea levels

will devastate coasts, will displace millions of people from coastal areas

The sun

without it, Earth would be dark and frozen, It supplies most of Earth's energy

The atmosphere

without it, Earth's temperature would be much colder, Clouds, land, ice, and water absorb 70% of incoming solar radiation, The remaining 30% is reflected back into space