Climate Control and Ozone Depletion Chapter 19

Vocabulary Carbon Capture and Storage

How Might the Earth’s Temperature and Climate change in the future? Objective 1

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 cooling and global warming respectively

Over the past 10,000 years – Interglacial period Characterized by a fairly stable climate and a fairly steady average global surface temperature Over the past 1,000 years – The average temperature of the atmosphere has remained fairly stable but began to rising during the last century

Estimated Changes in the Average Global Temperature of the Atmosphere

Our Climate, Lives, and Economies Depend on the Natural Greenhouse Effect Without the natural greenhouse effect – Earth would be cold and uninhabitable Primary Greenhouse Gases – Water Vapor H 2 O – Carbon Dioxide CO 2 – Nitrous Oxide NO x – Methane CH 4

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 in lower atmosphere – Main sources: agriculture, deforestation, and burning of fossil fuels Correlation of rising CO 2 and CH 4 with rising global temperatures and sea levels Countries with the largest CO 2 emissions (in order) – US, China, the European Union (with 27 countries), Indonesia, Russia, Japan, and India

Scientific and economic studies – 2007: Field and Marland Tipping point – the irreversible estimated threshold for large scale climate changes – CO 2 levels exceeding 450 ppm – In 2007 CO 2 levels were 384 ppm Ice core analysis of air pollutants – 60% of methane emissions during the last 275 years are the result of human activity – Nitrous Oxide emissions have risen about 20%

Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers

Atmospheric Levels of CO 2 Temperatures Sea Levels Atmospheric Levels of CH 4

The Atmosphere Is Warming Mostly Because of Human Activities Intergovernmental Panel on Climate Change (IPCC) – Very likely (90–99%) that lower atmosphere is warming and that human activities are responsible for most of the recent temperature increase 2007 IPCC report – 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

Melting of Alaska’s Muir Glacier between 1948 and 2004

The Big Melt: Some of the Floating Sea Ice in the Arctic Sea

Simplified 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 1975 – Troposphere has warmed – Stratosphere has cooled – If you increase the output from the sun, you increase the amount of energy that arrives at the top of the Earth’s atmosphere and get heating throughout the atmosphere This is not what a hotter sun would do

Can the Oceans Save Us? The world’s oceans have absorbed about half of all the CO 2 released to the atmosphere since the beginning of the Industrial Revolution Warmer oceans – CO 2 levels increasing acidity by 30% CO 2 + H 2 O  H 2 CO 3 (Carbonic Acid) – Effect on atmospheric levels of CO 2 – Decrease ability of corals to make CaCO 3 shells and bodies Antarctica’s Southern Ocean & North Atlantic Ocean – Solubility of CO 2 decreases with increasing temperature

Cancun Mexico

There Is Uncertainty about the Effects of Cloud Cover on Global Warming Warmer temperatures create more clouds – Thick, light-colored low altitude clouds decrease surface temperature – Thin, cirrus clouds at high altitudes increase surface temperature Effect of jet entrails on climate temperature – NASA scientists found that jet contrails expand and turn into large cirrus clouds that tend to release heat

What Are Some Possible Effects of a Warmer Atmosphere? Objective 2

Enhanced Global Warming Could Have Severe Consequences 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

Projected Effects of Global Warming and the Resulting Changes in Global Climate

Ice and Snow Are Melting Why will global warming be worse in the polar regions? – The arctic sea ice plays an important role in the earth’s climate by affective the average amount of precipitation Important climate role of floating sea ice – Because ice is floating, it does not increase sea level when it melts – Rising sea levels will come from land-based ice that melts Mountain glaciers affected by two factors – Average snowfall – adds to their mass – Average warm temperatures – take mass away (melt)

Science Focus: Melting Ice in Greenland Largest island – 80% composed of glaciers Some up to 2 miles deep – Population = 60,000 people The glaciers contain ~10% of the world’s fresh water 1996–2007: net loss of ice doubled

Areas of Glacial Ice Melting in Greenland during Summer 1982–2007 Increased

Sea Levels Are Rising According to the 2007 IPCC report, the world’s average sea level is very likely (90-99% certainty) to rise centimeters (0.6 – 1.9 feet) during this century. – Expansion of warm water About 2/3rds of the increase will result from the expansion of water as it warms – Melting of land-based ice About 1/3 rd of the increase will result from land ice melting

Projected irreversible effects – 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 – In US » Louisiana, North Carolina, Texas, and South Carolina Agricultural lowlands and deltas – Coastal areas where much of the world’s rice is grown – Contamination of freshwater aquifers With salt water Decreased supply of groundwater – Currently used for irrigation, drinking, and cooling power plants – Submergence of low-lying islands in the Pacific and Indian Oceans and the Caribbean Home to 1 of every 20 of the world’s people

Areas of Florida, U.S., to Flood If Average Sea Level Rises by One Meter

Low-Lying Island Nation: Maldives in the Indian Ocean

Permafrost Is Likely to Melt: Another Dangerous Scenario Carbon present as CH 4 in permafrost soils and lake bottoms – times the amount emitted as CO2 from burning fossil fuels each year – If the permafrost in soil and lake bottoms melts, significant amounts of methane will be released into the atmosphere. 2004: Arctic Climate Impact Assessment – 10–20% of the permafrost might thaw this century Permafrost Layer

Projected Decline in Arctic Tundra in Portions of Russia from 2004 to 2100

Ocean Currents Are Changing but the Threat Is Unknown Ocean Currents transfer CO 2 and warm water between the tropics and the poles – This can cause Melting glaciers, particularly in Greenland Increased rain in the North Atlantic – Could add enough fresh water to the ocean to slow the currents

Extreme Weather Will Increase in Some Areas Heat waves and droughts will increase in some areas – Kill large numbers of people – Reduce crop production – Expand deserts Prolonged rains and flooding in other areas Will storms get worse? – More studies needed before conclusions are drawn – Hurricane Katrina Occurred in 2005 when Atlantic waters were especially warm

Global Warming Is a Major Threat to Biodiversity Most susceptible ecosystems Coral reefs Polar seas Coastal wetland Alpine and arctic tundra High-elevation mountaintops

Changes in Average Ocean Temperatures, Relative to Coral Bleaching Threshold

What about – Migratory animals Biological clocks of birds and whales will be disrupted – Forests Forest fires will increase Oak-Pine and Oak-Hickory forests may expand northward Which organisms could increase with global warming? – Insects Pine Beetle: Damage Trees – Fungi Damage Trees – Microbes

Exploding Populations of Mountain Pine Beetles in British Columbia, Canada The Brown Trees are Dead

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 Less productivity; soil not as fertile

Climate Change Will Threaten the Health of Many People Deaths from heat waves will increase – Summer 2003 – 52,000 Europeans killed in heat wave – BUT, 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

What Can We Do to Slow Climate Change? Objective 3

Dealing with Climate Change Is Difficult Global problem – International cooperation is required to deal with the threat Long-lasting effects – CO 2 emitted from burning coal last about 120 years – Once set into motion, irreversible climate change will last hundreds to thousands of years Long-term political problem – Voters and Elected officials generally respond well to short-term problems Harmful and beneficial impacts of climate change unevenly spread – Higher latitude nations will have higher crop yields, fewer crop yields,, fewer deaths in winter, lower heating bills, and more tourism Many proposed actions disrupt economies and lifestyles – Phasing out fossil fuels

What Are Our Options? Two approaches or a mixture of both – Drastically reduce the amount of greenhouse gas emissions To slow down rate of warming in time to prevent climate changes – Devise strategies to reduce the harmful effects of global warming Recognize that some warming is unavoidable Will we reach a political tipping point before we reach irreversible climate change tipping points? – Political tipping point = pressure could force elected officials and business leaders to implement solutions on an urgent basis to avoid reaching irreversible climate change

Avoiding Catastrophe: We Can Reduce the Threat of Climate Change 3 major input or prevention strategies 1)Improve energy efficiency to reduce fossil fuel use 2)Stop cutting down tropical forests 3)Shift from non renewable carbon-based fossil fuels to a mix of carbon-free renewable energy A 4 th strategy – which is an output strategy 4) Keep burning fossil fuels, but capture and store CO 2 in soil, in vegetation, underground, and in the deep ocean  Then hope that it will never leak out

US scientists Socolow and Pacala – Have outlined at plan to keep CO 2 emissions to 2007 levels by 2057 Climate stabilization wedges – 15 different strategies that would reduce CO 2 emissions Swedish scientist Brown says we need to do more – Cut CO 2 emissions by 80% by 2020 – Plant 4 billion trees Assuming ½ will survive – Plant large areas of degraded land with fast growing perennial plants

Fifteen Ways to Cut CO 2 Emissions Page 515 of text

Some Output Methods for Removing CO 2 from the Atmosphere and Storing It

Case Study: Is Capturing and Storing CO 2 the Answer? Carbon capture and storage (CCS) – removing CO 2 from the smokestacks of coal burning power and industrial plants and then store it somewhere Several problems with this approach – Power plants using CCS More expensive to build None currently exist – Unproven technology – removes only part of the CO 2 – Large inputs of energy to work Increasing CO 2 emissions and cancel out the goal of CCS – Promotes the continued use of coal (world’s dirtiest fuel) – Government subsidies and tax breaks could be used to promote Solar, wind, geothermal, and other renewable sources – Stored CO 2 would have to remain sealed forever: no leaking

Should We Use Geo-Engineering Schemes to Help Slow Climate Change? CCS is one proposed geo-engineering scheme – Long-term effects unknown Injection of sulfate particles into the stratosphere – Use balloons and jet planes – This could (in theory) reflect some of the sun’s light – Would it have a cooling effect? – Would it accelerate O 3 depletion? – There are a lot of unknown effects

Pollution makes me sick!

Remove HCl from seawater – To reduce ocean acidity Pump up nutrient-rich deep ocean water – Anchor huge vertical pipes in the sea to pump nutrient rich water to fertilize algae – This would remove CO 2 from the atmosphere and emit dimethyl sulfide Could contribute to production of low clouds that would reflect sun Re-ice the Arctic – Tow 800,000 ice-making barges to the Arctic each year

Governments Can Help Reduce the Threat of Climate Change Strictly regulate CO 2 and CH 4 as pollutants Cap-and-trade approach – Put a cap on the amount of CO 2 and CH 4 emissions in a country, issue permits to emit these pollutants, and then let polluters trade their permits in the marketplace Increase subsidies to encourage use of energy-efficient technology Technology transfer – Governments of developed countries could help fund the transfer of the latest green technologies to developing countries

Governments Can Enter into International Climate Negotiations: The Kyoto Protocol 1997: Treaty to slow climate change – 174 of the world’s 194 countries (not the US) The Kyoto Protocol – Reduce emissions of CO 2, CH 4, and N 2 O to levels of 1990 by 2012 – Trading greenhouse gas emissions among countries – Not signed by the U.S. President G.W. Bush’s reasons – Harm the US economy – Did not require emission reduction by developing countries » China, India, or Brazil

We Can Move Beyond the Kyoto Protocol 2004: Stewart and Wiener – Countries should work together to form a new treaty Should be led by the U.S. – The Kyoto Protocol would have little effect on future global warming without support and action by the US, China, India, Brazil, and Indonesia Cap-and-trade emissions program – Include developing countries omitted from the trading plan originally Set up 10 year goals – Over the next 40 years

Some Governments Are Leading the Way Costa Rica: goal to be carbon neutral by 2030 Norway: aims to be carbon neutral by 2050 If China and India continue their massive coal burning and other high-carbon activities, the world will not be able to avoid the projected harmful effects of climate change U.S. cities and states taking initiatives to reduce carbon emissions

Some Companies and Schools Are Reducing Their Carbon Footprints Major global companies reducing greenhouse gas emissions – Alcoa – DuPont – IBM – Toyota – GE – Wal-Mart Fluorescent light bulbs Auxiliary power units on truck fleets Overhead passive solar lighting (Valrico and 60)

What is your carbon footprint? – Nature.org/climatecalculator – Epa.gov/climatechange/emissions/ind_calculator.html – Carbonfootprint.com – Gocarbonzero.org What can you do? – Nativeenergy.com – My-climate.com – Climatecare.org – Carbon-clear.com

We Can Prepare for the Harmful Effects of Climate Change Reduce greenhouse gas emissions as much as possible Move people from low-lying coastal areas Limit coastal building Remove hazardous material storage tanks away from the coast Genetically engineer crops more tolerant to drought Stockpile 1–5 years of key foods Waste less water Connect wildlife reserves with corridors

Ways to Prepare for the Possible Long- Term Harmful Effects of Climate Change

How Have We Depleted O 3 in the Stratosphere and What Can We Do? Objective 4

Our Use of Certain Chemicals Threatens the Ozone Layer Ozone Thinning – Ozone depletion varies with altitude and location – Seasonal depletion in the stratosphere Antarctica and Arctic 1930: Midgely – Discovered the first CFC – Chemically unreactive, inexpensive, odorless, nonflammable, nontoxic, and noncorrosive compounds seemed to be the dream chemical 1984: Rowland and Molina – CFCs were depleting O 3

Global Average Total Ozone Values in the Stratosphere from 1979–2005

Massive Ozone Thinning over Antarctica in 2007

Summary of CFCs and Other Chlorine- Containing Compounds that Destroy Ozone

Why Should We Worry about Ozone Depletion? Damaging UV-A and UV-B radiation will reach earth’s surface – Increase eye cataracts and skin cancer Impair or destroy phytoplankton – Significance? Phytoplankton are responsible for 50% of the O 2 produced in the world

Structure of the Human Skin and the Relationship between UV and Skin Cancer

Fig. 19-E (2), p. 526

What Can You Do? Reducing Exposure to UV Radiation

We Can Reverse Stratospheric Ozone Depletion Stop producing all ozone-depleting chemicals 60–100 years of recovery of the O 3 layer 1987: Montreal Protocol – Cut CFC emissions by 35% between 1989 and : Copenhagen Protocol – An amendment that phased out key ozone-depleting chemicals Ozone protocols: prevention is the key – Use prevention to solve environmental problems Substitutes for CFCs are available

SUMMARY List five ways in which you can reduce your carbon footprint. What are the four major strategies for slowing projected climate change? How can positive feedback loops affect future temperature changes and thus global temperature?