Climate Change Chapter 19

An Enormous Cloud of Air Pollutants and Ash from Mt. Pinatubo  June 1991: Mount Pinatubo (Philippines) exploded  Airborne pollutants, deaths, and damage  Affected climate temperature  James Hansen(NASA) cooled the temp of the earth by )0.5* over a 19 th month period. Then the earth would warm

Earth’s Future Temperature and Climate Change The overwhelming scientific consensus is that the earth’s atmosphere is warming rapidly, mostly because of human activities, and that this will lead to significant climate change during this century.

Global Warming and Global Cooling Are Not New Over the past 4.7 billion years the climate has been altered by Volcanic emissions Changes in solar input Movement of the continents Impacts by meteors Over the past 900,000 years Glacial and interglacial periods

Global Warming and Global Cooling Are Not New  Over the past 10,000 years ◦ Interglacial period, fairly stable climate and steady average global surface temperature  Over the past 1,000 years ◦ Temperature stable but began to rise during the last century when forests cleared, fossil fuel burned  Over the past 100 years ◦ Temperature changes mostly since 1975

Different techniques……..  Analysis of radioisotopes in rocks and fossils  Plankton and radioisotopes in ocean sediments  Tiny bubbles of ancient air found in ice cores from glaciers  Temperature measurements taken at different depths from bore holes drilled deep into the earth’s surface  Pollen from lake/bog bottoms  Tree rings  Historical records

Estimated Changes in the Average Global Temperature of the Atmosphere

Our Climate, Lives, Economies Depend on the Natural Greenhouse Effect ( Arrhenius) W ithout the natural greenhouse effect, warms the earth’s lower atmosphere and surface. Solar energy absorbed by the earth radiates into the atmosphere as infrared radiation(heat) 1% of earth’s lower atmosphere is compressed of greenhouse gases- water vapor, carbon dioxide, methane, and nitrous oxide Cold, uninhabitable earth

Human Activities Emit Large Quantities of Greenhouses Gases Since the Industrial Revolution (275 years ago) CO 2, CH 4, and N 2 O emissions higher Main sources: agriculture, deforestation, and burning of fossil fuels Correlation of rising CO 2 and CH 4 with rising global temperatures, during past 400,000 years Countries with the largest CO 2 emissions- US, China, EU-27 contries, Indonesia, Russia, Japan, India

Human Activities Emit Large Quantities of Greenhouses Gases  Per capita emissions of CO 2 Scientific and economic studies ◦ 2007: Field and Marland 560 ppm by 2050 – 1390 by 2100 Tipping point 450 ppm ◦ 2008: Aufhammer and Carson  China’s CO 2 emission growth may be underestimated  Ice core analysis – 60% of methane emissions ◦ human impact – landfills, raising live stock, extracting fossil fuels ◦ Nitrous oxide – nitrogen fertilizers

Atmospheric Levels of CO 2 and CH 4, Global Temperatures, and Sea Levels

The Atmosphere Is Warming Mostly Because of Human Activities Intergovernmental Panel on Climate Change (IPCC) 90–99% likely that lower atmosphere is warming 1906–2005: Ave. temp increased about 0.74˚C 1970–2005: Annual greenhouse emissions up 70% Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth Melting of glaciers and floating sea ice Prolonged droughts: increasing Last 100 years: sea levels rose 10–20 cm

Alaska’s Muir Glacier Al Gore and the IPCC : Nobel Peace Prize Natural and human- influenced factors could have an effect on temperature changes

The Big Melt: Some of the Floating Sea Ice in the Arctic Sea Drop in average cover of summer arctic ice

Scientific Consensus about Future Temperature Change? Mathematical models used for predictions Global warming: rapid rate Human factors are the major cause of temperature rise since 1950 Human factors will become a greater risk factor

Model of Some Major Processes That Interact to Determine Climate

Comparison of Measured Temperature from 1860– 2007 and Projected Changes

Is a Hotter Sun the Culprit? Since satellite and balloon measurements Troposphere has warmed Stratosphere has cooled Scientists have concluded that the rapid rise in global mean temperature could not be the result of increased solar output

Can the Oceans Save Us? Solubility of CO 2 in ocean water – removes 25-30% of the carbon dioxide pumped into the lower atmosphere by human activities. Some of it converted to insoluble carbonate salts that are buried in the bottom sediments Warmer oceans Solubility decreases increases atmospheric CO 2 Coral reefs destroyed Increased acidity –less carbon dioxide absorbed, increases growth of some algae drop in populations of phytoplankton, Antarctica’s Southern Ocean and the North Atlantic Ocean –decrease in carbon dioxide uptake

There Is Uncertainty about the Effects of Cloud Cover on Global Warming Warmer temperatures create more clouds by increased evaporation of surface water Thick, light-colored low altitude clouds: decrease surface temperature Thin, cirrus clouds at high altitudes: increase surface temperature Effect of jet contrails on climate temperature – they expand and turn into cirrus clouds that release heat into the upper troposphere

Outdoor Air Pollution Can Temporarily Slow Global Warming Aerosol and soot pollutants light colored sulfate particles, reflect sunlight and cool atmosphere sulfate particles also cool the lower atmosphere by forming condensation nuclei that form cooling clouds

Some Possible Effects of a Warmer Atmosphere…………… The projected rapid change in the atmosphere's temperature during this century is very likely to Increase drought and flooding, shift areas where food can be grown, raise sea levels, result in intense heat waves, cause the premature extinction of many species.

Enhanced Global Warming Could Have Severe Consequences Very rapid, global change in climate – projected rapid increase in average temperature in the lower atmosphere Worst-case scenarios Ecosystems collapsing Low-lying cities flooded Wildfires in forests Prolonged droughts: grasslands become dust bowls More destructive storms Glaciers shrinking; rivers drying up

Fig. 19-7, p. 507 Stepped Art

Severe Drought Is Increasing from 15-30% less moisture in the soil – NPP will decrease stream flows and available water will decline Biodiversity will decrease growth of plants/trees will slow forest and grassland fires will increase some lakes/seas will shrink and disappear, rivers will fail to reach the sea 1-3 billion people will face water shortage dry climate biomes will increase – savannas, chapparal,deserts

Ice and Snow Are Melting global warming be worse in the polar regions – exposure of darker land, absorb more solar radiation floating sea ice disappearing – could affect the average rate of precipitation in certain areas Mountain glaciers affected by Average snowfall, adds to mass in winter Average warm temperatures- apur their melting during the summer

Ice and Snow Are Melting Europe’s Alps Glaciers are disappearing South America Glaciers are disappearing Greenland Warmer temperatures Areas of Glacial Ice Melting in Greenland

Melting Ice in Greenland Largest island: 80% composed of glaciers 10% of the world’s fresh water 1996–2007: net loss of ice doubled Effect on sea level if melting continues

Sea Levels Are Rising – 90-99% certainity Expansion of warm water and melting of land based ice– Water will rise cm ( feet) during this century storm surges of 6 meters (20 feet) accompanying tropical cyclones and tsunamis

Sea Levels Rising Degradation and loss of 1/3 of coastal estuaries, wetlands, and coral reefs Disruption of coastal fisheries Flooding of Low-lying barrier islands and coastal areas Agricultural lowlands and deltas Contamination of freshwater aquifers Submergence of low-lying islands in the Pacific and Indian Oceans and the Caribbean Maldives- Indian Ocean

Projected Decline in Arctic Tundra in Portions of Russia from Melting of permafrost in tundra soils releases methane and carbon di oxide Loss of arctic tundra-reduce grazing lands for caribou Boreal vegetation would replace tundra

Ocean Currents Are Changing but the Threat Is Unknown Melting glaciers, particularly in Greenland Increased rain in the North Atlantic Could add enough fresh water to disrupt the flow of deep and shallow ocean currents Could climate of Northern Europe. N. America and Japan Not thought to be an immediate problem on the ocean currents

Extreme Weather Will Increase in Some Areas Heat waves and droughts in some areas- kill people, reduce crop production, expand deserts Prolonged rains and flooding(flash floods) from heavy and prolonged precipitation Will storms get worse? More studies needed – Saunders and Lea (2008) Hurricanes Katrina and Rita – lost 320 million big trees

Global Warming Is a Major Threat to Biodiversity Most susceptible ecosystems Coral reefs Polar seas Coastal wetland High-elevation mountaintops Alpine and arctic tundra Changes in water temperature, relative to coral bleaching threshold

Global Warming Is a Major Threat to Biodiversity 30% of land –based plants and animals will disappear (temp change *C) What about Migratory animals Forests Some organisms will increase Insects, Fungi, Microbes Exploding populations of mountain pine beetles Destroy lodge pole pine forests

Climate Change Will Shift Areas Where Crops Can Be Grown Regions of farming may shift Decrease in tropical and subtropical areas Increase in northern latitudes Overall food productivity would decrease because of less productivity soil Decrease in food production in farm regions dependent on rivers fed by snow melt Genetically engineered crops more tolerant to drought

Climate Change Will Threaten the Health of Many People Deaths from heat waves will increase Deaths from cold weather will decrease Higher temperatures can cause Increased flooding Increase in some forms of air pollution, more O 3 More insects, microbes, toxic molds, and fungi Norman Myers – 150 to 200 million environmental refugees in this century

What Can We Do to Slow Climate Change…………….. To slow the rate of global warming and climate change, we can increase energy efficiency, sharply reduce greenhouse gas emissions, rely more on renewable energy resources slow population growth.

What Can We Do to Slow Climate Change? Governments can subsidize energy efficiency and renewable energy use, tax greenhouse gas emissions, set up cap-and-trade emission reduction systems, help to slow population growth.

Dealing with Climate Change Is Difficult  Global problem  Long-lasting effects  Long-term political problem  Harmful and beneficial impacts of climate change unevenly spread  Many proposed actions disrupt economies and lifestyles

What Are Our Options? Two approaches Drastically reduce the amount of greenhouse gas emissions Recognize that some warming is unavoidable and devise strategies to reduce the harmful effects of global warming Will we reach a political tipping point before we reach irreversible climate change tipping points?

We Can Reduce the Threat of Climate Change Input or prevention strategies Improve energy efficiency to reduce fossil fuel use Shift from non-renewable carbon-based fossil fuels to a mix of carbon-free renewable energy resources Stop cutting down tropical forests Output strategy Capture and store CO 2 -

Avoiding Catastrophe: We Can Reduce the Threat of Climate Change Socolow and Pacala Climate stabilization wedges Keep CO 2 emissions to 2007 levels by 2057 Brown: need to do more Cut CO 2 emissions by 80% by book: Plan B 3.0: Mobilizing to Save Civilization

We Can Reduce the Threat of Climate Change Output solutions Massive global tree planting – 4 billion need to be planted Wangari Maathai Great Wall of Trees: China and Africa Plant fast-growing perennials such as switch grass on degraded land which takes carbon dioxide from the air and stores it in the soil. Can be used to produce ethanol

Fig , p. 515 SOLUTIONS Global Warming Prevention Cleanup Cut fossil fuel use (especially coal) Remove CO 2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO 2 by planting trees Improve energy efficiency Sequester CO 2 deep underground (with no leaks allowed) Shift to renewable energy resources Transfer energy efficiency and renewable energy technologies to developing countries Sequester CO 2 in soil by using no-till cultivation and taking cropland out of production Reduce deforestation Sequester CO 2 in the deep ocean (with no leaks allowed) Use more sustainable agriculture and forestry Repair leaky natural gas pipelines and facilities Limit urban sprawl Reduce poverty Use animal feeds that reduce CH 4 emissions from cows (belching) Slow population growth

Fifteen Ways to Cut CO 2 Emissions

Fig , p. 515 Stepped Art

Fig , p. 516 Oil rig Tanker delivers CO 2 from plant to rig Coal power plant Tree plantation CO 2 is pumped down from rig for disposal in deep ocean or under seafloor sediments Abandoned oil field Switchgrass Crop field CO 2 is pumped underground Spent oil or natural gas reservoir Spent coal bed cavern Deep, saltwater-filled cavern = CO 2 pumping = CO 2 deposit Some Output Methods for Removing CO 2 from the Atmosphere and storing it

Is Capturing and Storing CO 2 the Answer? Carbon capture and storage (CCS) – involves removing carbon dioxide from the smoke stacks of coal- burning power and industrial plants and storing them somewhere Several problems with this approach Power plants using CCS More expensive to build None exist Unproven technology Large inputs of energy to work promotes continued use of coal Effect of government subsidies and tax breaks Stored CO 2 would have to remain sealed forever: no leaking

Use Geo-Engineering Schemes to Help Slow Climate Change…….. CCS – large scale geo engineering scheme opposed by scientists because long term effects on earth’s energy flow, chemical cycling processes and vital biodiversity are unknown Injection of sulfate particles into the stratosphere by balloons, large jet planes, giant cannons Huge amounts of sulfur dioxide injected into the atmosphere every 2 years Would it have a cooling effect? Would it accelerate O 3 depletion?

Use Geo-Engineering Schemes to Help Slow Climate Change…… Remove HCl from seawater – reduce ocean acidity. How would it affect the ecology ? Pump up nutrient-rich deep ocean water and cause algal blooms, remove carbon dioxide and emit dimethyl sulfide which will contribute to the formation of low clouds that would reflect sunlight Re-ice the Arctic – 8,000 ice making barges Wrap large areas of the glaciers with insulating blankets

Cost to Slow Climate Change…. Short-term costs lower Local and global economies may be boosted Provide jobs because of new technology associated with alternative energy Less expenses for remediation

Governments Can Help Reduce the Threat of Climate Change Strictly regulate CO 2 and CH 4 as pollutants Cap-and-trade approach-political advantage carbon taxes - levy energy taxes on each unit of fossil fuel that is burned – tax pollution, not payrolls Increase subsidies to encourage use of energy-efficient technology Technology transfer-fund the transfer of green technologies to phase out older, energy wasting technologies

Governments Can Enter into International Climate Negotiations: The Kyoto Protocol 1997: Treaty to slow climate change delegates from161 nations 1 st phase – 174 of the world’s 194 countries (but not US) ratifying the agreement by mid The Kyoto Protocol Reduce emissions of CO 2, CH 4, and N 2 O by 2012 to levels of 1990 Trading greenhouse gas emissions among countries Not signed by theUS.(2001) 67% of ppublic upset President G.W. Bush’s reasons-would harm US economy Cap and Trade systems need to have the caps set low to increase value of the tradable allowances

Move Beyond the Kyoto Protocol  2004: Stewart and Wiener ◦ New treaty needed  Should be led by the U.S.  Include China, India, Brazil and other developing countries that are getting industrialized and will be soon emitting the more than 50% of the world’s greenhouse gases  Cap-and-trade emissions program  Set up achievable 10 year goals – to reduce greenhouse gases over the next 40 years

Governments Are Leading the Way are…… Costa Rica: goal to be carbon neutral by 2030 – 78% from hydroelectric,18% from wind and geothermal Norway: aims to be carbon neutral by 2050 China and India must change energy habits U.S. cities and states (27+ DC: solar and wind) taking initiatives to reduce carbon emissions 650 cities around the world, including 453 US cities reduce greenhouse gases Portland, Oregon – greenhouse gases at 1990 levels

Reducing Greenhouse Gas Emissions in California ( 12 th largest producer of greenhouse gases ) Use of energy-efficient appliances and buildings Incentives for consumers to use less energy Has saved California from building 24 new power plants California sued the EPA so that they and 17 other states can set tougher emission standards

Some Companies and Schools Are Reducing Their Carbon Footprints Major global companies reducing greenhouse gas emissions- reduce % below 1990 levels by 2010 Alcoa DuPont IBM Toyota GE Wal-Mart $12 million /year saved by using LED’s Fluorescent light bulbs Auxiliary power units on truck fleets – no idling Carbon Disclosure Project

Some Companies and Schools Are Reducing Their Carbon Footprints Colleges and universities reducing greenhouse gas emissions Oberlin College, Ohio, U.S. 25 Colleges in Pennsylvania, U.S. Yale University, CT, U.S. Largest teach-In Feb colleges, climate change and sustainability

What Can You Do? Reducing CO 2 Emissions

Prepare for the Harmful Effects of Climate Change Reduce greenhouse gas emissions as much as possible (50-85% cut in by 2050) to prevent the planet from heating up by 2*C Move people from low-lying coastal areas Limit coastal building Remove hazardous material storage tanks away from the coast

Prepare for the Harmful Effects of Climate Change Genetically engineer crops more tolerant to drought Stockpile 1–5 years of key foods Waste less water Connect wildlife reserves with corridors

Fig , p. 522 Develop crops that need less water Waste less water Connect wildlife reserves with corridors Move people away from low-lying coastal areas Move hazardous material storage tanks away from coast Stockpile 1- to 5-year supply of key foods Prohibit new construction on low-lying coastal areas or build houses on stilts Expand existing wildlife reserves toward poles Which do you think is the most important ?