Chapter 18- Global Climate Change

negative feedback loop

A feedback loop that causes a system to change in the opposite direction from which it is moving -more atmospheric water vapor could enhance cloudiness, reflecting sunlight back into space and slow warming

Albedo

Ability of a surface to reflect light -Light surface, snow, ice, glacier - High albedo -dark surface, Soil,- low albedo

carbon tax

An alternative to carbon trading is the_______ on the emission of carbon dioxide or the carbon content of fossil fuels -Can be charged to producers, utilities, or motor vehicle users -A downside is that these fees often get directly passed along to the customers

social cost of carbon

An estimate of the total economic cost of damages resulting from the emission of carbon dioxide (from fossil fuel burning, deforestation, etc.) and resulting global climate change, on a per-ton basis. - is estimated to be somewhere between $10-350 per ton Economically, climate change is expected to widen the gap between the rich and poor, as people with less wealth rely more heavily on resources likely to be disrupted • In the Arctic, ice sheets are melting, sea ice is thinning, storms are increasing, and native people and animals are having more difficulty hunting The Stern Review on the Economics of Climate Change concluded that climate change could cost the world 5-20% of GDP by the year 2200 • Investing just 1% of GDP starting now could help to avoid many of these costs

carbon footprint

Everyone has a _________ that expresses the amount of carbon we are responsible for emitting • Individual decisions that reduce carbon footprints will play a major role in addressing climate change -Choosing energy-efficient appliances -Eating less meat -Living near your work to reduce commuting times

Ozone concentration

Ozone concentration in the troposphere has also grown, the result of photochemical smog

Both adaptation and mitigation

are needed to deal with climate change, because even if we halted all emissions now, pollution already in the atmosphere would continue driving global warming until equilibrium was reached

Future changes in temperature

are predicted to vary from region to region • Polar regions, for example, are expected to experience the most severe warming A warmer atmosphere speeds evaporation and holds more water vapor, and precipitation has increased worldwide by 2% over the past century • Overall,some regions are receiving above average amounts of rain and snow, while others receive less

Climate models

are programs that combine what is known about atmospheric circulation, ocean circulation, atmosphere-ocean interactions, and feedback cycles to simulate climate dynamics -model efficiency is tested by entering past climate data and running the model toward the present -models are imperfect because the Earth's climate system is complex, and many feedback systems are not known

Carbon offsets

are voluntary payments paid by a producer that is unable to reduce its emissions, and given to another institution that can • For example, a coal plant could buy offsets that would fund a reforestation project

Greenhouse gases

atmospheric gases having three or more atoms in their molecules -tend to absorb infrared radiation given off by the Earth's surface then re-emit it back downward -include water vapor (H2O), ozone (O3), carbon dioxide (CO2), nitrous oxide(N2O), methane(CH4), and halocarbons In the United States, temperatures in most areas have risen by more than 1 full degree Fahrenheit in just the past two decades • This trend will continue because we are still emitting greenhouse gases, and the ones already in the atmosphere will continue warming the globe for decades to come

Carbon capture and storage

refers to technologies or approaches that remove carbon dioxide from emissions and then store it belowground under pressure in deep salt mines, depleted oil and gas deposits, or other underground reservoirs • These technologies and spaces are not yet adequate for sequestering enough carbon to impact global atmospheric levels

A warmer atmosphere

speeds evaporation and holds more water vapor, and precipitation has increased worldwide by 2% over the past century • Overall, some regions are receiving above average amounts of rain and snow, while others receive less

Carbon pricing

strategies are designed to compensate the public for the external costs we all suffer from climate change resulting from greenhouse gas emissions • Carbon pricing removes the burden of paying for these impacts from the public and shifts it to the entities responsible for emissions • In theory, if producers are charged a price for emissions, they will have a strong economic incentive to devise ways to reduce emissions

Climate change impacts

the physical properties of our planet, on organisms and ecosystems, and on human well- being -The average surface temp has risen 1.60F since the 1900 and will raise 1.8 to 6.7F by 2100 - Ice sheet and glaciers will continue to melt contributing to sea levels rising - precipitation has increased. It will continue to vary by region making wet areas wetter and dry ones drier -Heavy precipitation events and flooding will continue to increase -Heatwaves and droughts will longer, more frequent and more severe in many places -The Arctic has warmed faster than many regions and will continue to do so -The Arctic will soon be ice-free in the summer -Oceans have warmed and circulation may be affected as it get warmer -Oceans are becoming more acid - Sea levels are rising

Global warming potential

the relative ability of a greenhouse gas molecule to contribute to warming • values are expressed in relation to carbon dioxide, which is assigned a value of 1

Proxy indicators

types of indirect measurements that serve as substitutes for direct measurement • Climate scientists drill into ice caps, ice sheets, and glaciers to analyze the tiny bubbles of atmosphere that collected as the ice formed • Glaciers in Antarctica have provided information dating back 800,000 years • Other proxy measurements include sediment cores drilled below bodies of water, tree rings, packrat middens in arid regions, and the isotope concentration of samples from coral reefs

positive forcing

warms the surface

Intergovernmental Panel on Climate Change (IPCC)

was established in 1988 by the United Nations to review and summarize all available data in climate studies for policymakers and the general public

fee-and-dividend

where the government transfers the carbon tax, or "fee," a tax refund, or "dividend," given to taxpayers • The fee-and-dividend approach is a type of revenue-neutral carbon tax, because there is no net transfer of revenue from taxpayers to the government

tropospheric temperatures increase

, more water should evaporate and enter the atmosphere There are two different scenarios for how this can affect climate change: more atmospheric water vapor could lead to more warming, causing more evaporation in a positive feedback loop more atmospheric water vapor could enhance cloudiness, reflecting sunlight back into space and slow warming in a negative feedback loop

Summary

- Earth has a dynamic climate system that is based on the sun, atmosphere and oceans - Greenhouse gases, such as water vapor, ozone, carbon dioxide, nitrous oxide, methane, and halocarbons, accumulate in the atmosphere and inducing a warming effect by trapping infrared energy back to the surface of the Earth called the Greenhouse Effect - Since the industrial revolution almost 200 years ago, human influences on the atmosphere and on climate have greatly exacerbated the amount of greenhouse gases emitted into the atmosphere artificially inducing global warming and climate change - Climate is studies many ways where scientists can study the oceans, paleoclimate, and proxy indicators to create climate models that explain Earth's current climate conditions and predict future climate conditions - There are documented and scientifically-based impacts and trends of Earth's current and changing climate in the United States and around the world - There are several ways humans around the world are addressing current climate change impacts, but everyone must take responsibility for their own carbon footprint and realistically address their personal impacts on Earth's climate

Climate change can contribute to humanitarian, geopolitical, and national security problems

-Economies and infrastructure may be weakened -Oil and gas flows can be disrupted -People in some affected regions may become refugees or turn to terrorism

A warmer climate exposes us to many potential health hazards

-More frequent heatwaves= heat stroke, heartattacts -Respiratory ailments due to more -photochemical smog -Expansion of tropical diseases, such as malaria, into temperate latitudes -Disease and sanitation problems from flooding of sewage treatment plants -Injuries and drowning from worsened storms

U.S. National Climate Assessment

2018 predicted many future impacts of climate change on the United States • Temperatures in the United States are predicted to rise by another 1.7-5.6°C by the end of this century, depending on how quickly emissions are reduced In the United States, temperatures in most areas have risen by more than 1 full degree Fahrenheit in just the past two decades

Jet streams

A 2012 study revealed a potential explanation for the increase in extreme weather Warming has been greatest in the Arctic, weakening the intensity of the Northern Hemisphere's polar jet stream • The jet stream is a high-altitude air current that blows west to east in a curving pattern that wanders north and south As the jet stream slows down, it's north and south loops become longer, forming an atmospheric blocking pattern because it blocks the eastward movement of weather patterns • This causes all weather patterns to be held in place for longer periods of time

ocean acidification

As carbon dioxide concentrations in the atmosphere rise, the oceans absorb more CO2 • sea water becomes acidic, a phenomenon referred to as ocean acidification • As seawater becomes more acidic, carbonate ions become less available and calcium carbonate dissolves, jeopardizing marine animals that produce shells • Globally, ocean chemistry has already decreased by 0.1 pH unit

carbon- neutrality

Carbon offsets are one way for producers to achieve ________, a condition where no net carbon is emitted

Carbon

Combustion of fossil fuels transfer carbon from one reservoir (underground deposits) to another (the atmosphere) • Forests,another reservoir,have been cleared, reducing the biosphere's ability to remove/store carbon dioxide

US population sea rise effect

Currently more than half of the U.S. population lives in coastal counties, and 3.7 million Americans live within 1 vertical meter of the high tide line • South Florida is judged to be the most at-risk, with 2.8 million people and 1.8 million acres vulnerable

Charles Keeling

In 1958, he began analyzing hourly air samples from a monitoring station at Hawaii's Mauna Loa Observatory • CO2 concentrations have increased from 315 ppm in 1958 to over 400 ppm today

Fifth Assessment Report

In 2013 and 2014, the IPCC released its Fifth Assessment Report, summarizing trends in surface temperature, precipitation patterns, snow and ice cover, sea levels, storm intensity, and other factors -The Sixth Assessment Report will be publish in 2022 Average surface temperatures (both land and ocean) have risen by about 1.1°C in the past 100 years • Most of this increase has occurred since the 1970s

Plant and animal changes

Many biological phenomena that rely on temperature have been modified due to global warming • In the spring, plants are leafing, insects are hatching, birds are migrating, and animals are breeding earlier • Many animals are expanding their ranges toward cooler areas (higher in elevation or latitude) Rainbow trout and cutthroat trout into bull trout Moderate warming may increase agricultural output in some temperate areas, but increased droughts will diminish yields for many others Increased CO2 may spur higher timber growth, but warming temperatures also increase the rates of invasive species, fires, and disease outbreaks

Meltwater

Many tropical mountaintop glaciers have disappeared, and the few that remain are shrinking • One out of six people worldwide live in regions that depend on mountain meltwater as a source of freshwater • Sandpoint, ID relies on mountain snowfall meltwaters as a source of freshwater • The Purcell Trench lies between the Selkirk Mountains (west of Sandpoint) an the Bitterroot Mountains (east of Sandpoint) and the only access to groundwater is near LPO and the Clark Fork and Pend Oreille Rivers

U.S. Mayors Climate Protection Agreement

Mayors from more than 1,000 cities have signed on to the U.S. Mayors Climate Protection Agreement, committing to policies that "meet or beat" Kyoto Protocol guidelines • The most aggressive is California, which has a goal to cut greenhouse gas emissions 25% by 2020, and has established a cap-and-trade program • States in the Regional Greenhouse Gas Initiative, including Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont run a joint cap-and-trade program

Milankovitch cycles

Over thousands of years, the Earth wobbles on its axis, varies in its tilt, and experiences changes in the shape of its orbit in regular long-term cycles • These changes all naturally vary the Earth's climate

Three factors exert the most influence on the Earth's climate

Sun • provides light and warmth Atmosphere • prevents major temperature shifts from night to day Oceans • stores and transport heat and moisture The sun supplies most of our planet's energy, which the atmosphere absorbs or reflects most of it before it even reaches the surface

Big problem many solutions

There is not a single "magic bullet" for mitigating climate change; rather, environmental scientists advocate breaking the problem up into smaller, more manageable strategies Many people disagree on what role the government should play • Shoulditmandatechangethrough laws and regulations? • Should no policies be implemented and private enterprise be allowed to develop their own solutions? Since the U.S. has high resource use and per capita emissions, policymakers often assume that restrictions on emissions will harm the economy Renewable energy has actually been an economic boom for countries like China and Germany

Sea level rise

Worldwide, average sea levels have risen 24.1 cm in the past 135 years • This leads to more beach erosion, coastal flooding, saltwater intrusion, and a greater impact by localized rises in sea level called storm surges • Along the U.S. coast, sea level is rising at varying rates Small island countries like the Maldives, most of which are less than 1 m above sea level, may become climate refugees as sea level rises • In 2009, the Maldives held an "underwater cabinet meeting" to bring attention to the plight of their country

positive feedback loop

a feedback loop in which change in a system is amplified more atmospheric water vapor could lead to more warming, causing more evaporation

Mitigation

aims to alleviate or reducethe severity of climate change by: Improving energy efficiency Switching to clean and renewable energy sources Preserving forests Recovering landfill gases Protecting soil quality

Climate

an area's long-term atmospheric conditions • Temperature • Precipitation • Wind • Humidity • Barometric pressure • Solar radiation Climate influences virtually everything around us, and climate change looks to be the phenomenon that mostly shapes the near future for young people

Automobiles

are inefficient—only 14% of the fuel burned actually moves cars down the road • Alternative technologies, such as hybrid or all-electric vehicles, hydrogen fuel cells, and alternative fuels will help alleviate this problem • The increased availability of mass transit, such as buses, subways, and light rail all reduce the number of cars on the road and greenhouse gas emissions

negative forcing

cools the surface

Global climate change

describes worldwide changes in temperature, precipitation, and the frequency and intensity of storms across the world -The Earth's climate varies naturally, but disruptive changes are unfolding rapidly, with human activities accelerating them

Storm surges

high water level brought by a storms that swamps low-lying areas impact increased by rising sea levels

Oceans

hold 50 times more carbon than the atmosphere • Naturally, oceans aren't meant to absorb large amounts of carbon and absorb less CO2 than we are adding to the atmosphere • Furthermore, carbon increases ocean pH which can alter ecosystems & organisms • As oceans warm, gases like CO2 are less soluble, creating a positive feedback loop that accelerates warming

Nitrous oxide

in the atmosphere has increased, primarily due to auto emissions, feedlots, and the use of synthetic nitrogen fertilizers

2018 Storm Season

incredible floods, storm surges,tornados & high winds -one of the more damaging storm seasons in recent years -15 named storms (avg. 12); 8 were hurricanes • 7 tropical storms; 4 were active at the same time Hurricane Florence—NorthCarolina Category 1: 144mph Store Surges: 6ft Hurricane Michael—Florida Category 4: 155mph Store Surges: 14ft

Geoengineering

is a risky idea that involves taking steps to directly alter the Earth's climate

carbon trading system

is one in which permits are traded for the emission of carbon dioxide • The government sets a cap on the amount of pollution it will allow, then gives, sells, or auctions permits to emitters that allow them to emit a certain fraction of the total amount Cap and Trade

Aerosols

microscopic droplets that can have either a warming or cooling effect when present in the atmosphere -soot particles ("black carbon aerosols") cause warming by absorbing solar energy -other aerosols (such as sulfur) reflect solar energy and have a cooling effect

Scientists agree that today's global warming is a result

of the increase in greenhouse gas concentrations in our atmosphere due to: • Combustionoffossilfuelsforenergy • Loss of carbon-absorbing vegetation due to deforestation and land/soil degradation • Public debates over climate change are primarily the result of corporate interests, political think tanks, and a handful of scientists funded by fossil fuel industries

Electricity generation

produces the largest portion (40%) of U.S. carbon dioxide emissions -Energy conservation technologies, such as new generations of light bulbs, appliances, and building materials, can reduce energy use and emissions by 30% or more -Switching from higher-pollution sources of energy, such as coal, to cleaner ones, such as natural gas, nuclear, and renewables also reduces emissions

Adaptation

pursues strategies to cushion ourselves from the impacts of climate change • The pump systems installed at Miami Beach is an example of an adaptation strategy

Global warming

refers specifically to an increase in Earth's average temperature, but this is only one aspect of global climate change

Radiative forcing

the amount of change in thermal energy that a given factor exerts on the Earth's temperature -positive forcing warms the surface -negative forcing cools the surface • When all factors are considered, the Earth is experiencing net radiative forcing of 2.3 watts/m2

paleoclimate

the climate in the ancient past, - is vital for providing a baseline against which we can measure changes to the climate today

Greenhouse effect

the re-warming of the lower atmosphere by the emitting of infrared energy by these gases -The greenhouse effect has been present throughout Earth's history and has kept the planet warm enough to support life • Over the past 250 years, humans have caused a net accumulation of greenhouse gases in the atmosphere, primarily due to the release of carbon in fossil fuels during combustion • source-sink disruption in the carbon cycle

Melting snow and ice

• As snow and ice melt, less reflective surfaces (bare ground or surface water) is exposed • This reduces the Earth's albedo, or capacity to reflect light, creating a positive feedback loop Polar ice is also melting very quickly, with the entire West Antarctic ice shelf potentially on its way to an unstoppable collapse • This would create a 3 m rise in sea levels The loss of Arctic sea ice has led to the opening of new shipping lanes, and many countries jockeying for position to claim regions of the Arctic for oil and mineral extraction Arctic warming is also thawing permafrost (permanently frozen ground), causing the release of underground methane, which further intensifies warming