Review Quiz and Island story

Watch temp change over 131 years in 26 sec http://www.climatecentral.org/videos/web_features/nasa-finds-2011-ninth-warmest-year-on-record/

Climate Change

Past climates Global cooling and warming occur in cycles Glacial and interglacial periods Glacial periods last about 100,000 years. Interglacial last about 10,000-12,500 years. Our current interglacial age has lasted about 12,000 years…

Glacial and Interglacial Periods Average temperature over past 900,000 years 17 16 15 14 Average surface temperature (°C) 13 12 11 10 9 900 800 700 600 500 400 300 200 100 Present Thousands of years ago Glacial and Interglacial Periods

Temperature change over past 22,000 years Agriculture established 1 Average temperature over past 10,000 years = 15°C (59°F) -1 End of last ice age Temperature change (°C) -2 -3 -4 -5 20,000 10,000 2,000 1,000 200 100 Now Years ago Past 22,000 years

Temperature change over past 1,000 years Temperature change (°C) 1.0 0.5 0.0 Temperature change (°C) -0.5 -1.0 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101 Year Past 1,000 years

Past 130 years Average temperature over past 130 years 15.0 14.8 14.6 14.4 Average surface temperature (°C) 14.2 14.0 13.8 13.6 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year Past 130 years

Ice can tell us WHAT? Past climate information is found through ice cores from Antarctica and Greenland. The ice core (see fig 21.3) can tell us: Greenhouse gas concentrations Solar activity Snowfall Forest fires (layers of soot) Core samples from lakes/ponds bottom tell us: Pollen Fossils Plant life Growth trends

Too much information!! What we do with all that information: IPCC: Intergovernmental Panel on Climate Change 2,000 experts from 70 nations IPCC uses probability to describe trends: Virtually certain: more than 99% probability Very likely: 90-99% probability Likely: 66-90% probability Our current interglacial age is likely to last another 15,000 years

Greenhouse Effect

What’s happening here? More greenhouse gases in the air, prevents heat moving out of the atmosphere. Added greenhouse gases absorb the heat.

Greenhouse Effect                                                  Heat is “trapped” inside the atmosphere much like heat is trapped in a greenhouse. What causes the “trapping”? Carbon Dioxide Methane NOx CFC’s HCFC’s Halons Water vapor (hasn’t changed – closed system) CF4 This animation shows how a carbon dioxide molecule vibrates when it absorbs heat.

Greenhouse Effect Heat is “trapped” inside the atmosphere much like heat is trapped in a greenhouse. What causes the “trapping” Carbon Dioxide Methane NOx CFC’s HCFC’s view clip Halons Water vapor (hasn’t changed – closed system) CF4

Selected Greenhouse Gases Carbon Dioxide (CO2) Source: Fossil fuel burning, deforestation Anthropogenic increase: 30% Average atmospheric residence time: 500 years Methane (CH4) Source: Rice cultivation, cattle & sheep ranching, decay from landfills, mining Anthropogenic increase: 145% Average atmospheric residence time: 7-10 years Nitrous oxide (N2O) Source: Industry and agriculture (fertilizers) Anthropogenic increase: 15% Average atmospheric residence time: 140-190 years

Effects to think about Increased death from heat, malnutrition Very likely (90-99%) that tree deaths from disease and pests will increase Very likely that wildfires will increase Loss of animals and plants that can’t migrate quickly enough Increase in pest (high tolerance) animals and insects Tree species would move toward polar regions (5 miles per decade now) Increased hurricanes (over warmer water)

CO2 effects 380 360 340 320 300 Concentration of carbon dioxide in the atmosphere (ppm) 280 Carbon dioxide 260 240 +2.5 220 200 Variation of temperature (˚C) from current level 180 –2.5 –5.0 –7.5 Temperature change End of last ice age –10.0 160 120 80 40 Thousands of years before present

Where’s all this gas from? Burning of fossil fuels (CO2 ) Deforestation (CO2) Clearing and burning grasslands (CO2) Larger cattle herds (CH4) Rice paddies/fertilizers (Nox and CH4 ) Automobiles (1 gallon of gas = 20 lbs. of CO2 ; one tank of gas = 360 lbs. of CO2)

Dirty, Rotten Americans! #1 producer of CO2 emissions (24% of world’s emissions) CO2 emissions from our cars is more than the emissions of everything that powers Japan! Each American produces more CO2 than any other nations individuals (per capita). 500 tons of CO2 in your lifetime! Huge amounts of methane from landfills and livestock.

The graphs say it all

Carbon dioxide (CO2) 410 360 Parts per million 310 260 1800 1900 2000 2100 Year Carbon dioxide (CO2)

Methane (CH4) 2.4 1.8 Parts per million 1.2 0.6 1800 1900 2000 2100 Year Methane (CH4)

Nitrous oxide (N2O) 320 310 Parts per million 300 290 260 1800 1900 2000 2100 Year Nitrous oxide (N2O)

Global Warming vs Climate Change Global warming: trend towards increasing temperatures. 10 warmest years on record have occurred since 1990. Global climate change: changes in precipitation, temperatures, storm intensity. Global warming can lead to global climate change.

Where’s the proof baby?

“Proof” of Global Warming 20th century was hottest on record Since 1861, average global temperature has risen between 1o- 1.4o F (most of that has been since 1980) 16 hottest years on record have been since 1980, 10 hottest have been since 1990. Glaciers and sea ice are shrinking. Sea level rising (4 to 8 inches)

1979 2003 Arctic Sea Ice Changes

Factors Affecting Earth’s Temperature Oceans can store heat and CO2, but no one knows how much. Cloud cover: can warm by trapping and releasing heat or cool by reflecting heat back to space (albedo effect)!

Albedo is measured on a scale from 0-1(or sometimes as a %). Very dark colors have an albedo close to 0 (or close to 0%). Very light colors have an albedo close to 1 (or close to 100%).

Albedo is measured on a scale from 0-1(or sometimes as a %). Forests have low albedo, near 0.15. Snow and ice, have very high albedo, as high as 0.8 or 0.9, and reflect most of the solar energy that gets to them, absorbing very little

Factors Affecting Earth’s Temperature Oceans can store heat and CO2, but no one knows how much. Cloud cover: can warm by trapping and releasing heat or cool by reflecting heat back to space (albedo effect)! Outdoor air pollution: aerosols can either warm or cool the atmosphere (much like clouds) Stimulate photosynthesis: more CO2 can temporarily cause higher photosynthesis. Temporary because plants will “level off” and die, releasing their CO2 Methane trapped under ice is released when the ice melts.

Solutions Global Warming Prevention Cleanup Cut fossil fuel use (especially coal) Remove CO2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO2 by planting trees Improve energy efficiency Shift to renewable energy resources Sequester CO2 deep underground Transfer energy efficiency and renewable energy technologies to developing countries Reduce deforestation Sequester CO2 in the deep ocean Use more sustainable agriculture Repair leaky natural gas pipelines and facilities Slow population growth Use feeds that reduce CH4 emissions by belching cows

Protocols

Protocols Kyoto Protocol: 1997; Reduce greenhouse gases. (concern is global warming) Montreal Protocol: 1987; Reduce use of CFC’s (concern is ozone depletion) Copenhagen Protocol: 1992; Reduce ozone depleting chemicals (concern is ozone depletion)

Kyoto Protocol International agreement 1997 161 nations Directs 39 countries to take steps to decrease greenhouse gas emissions. Developing countries were not held to the same standards as developed ones. 2001: G.W. Bush withdrew the US from the agreement because of expense and the fact that developing countries like China and India weren’t held accountable.

Pollutant Chart Which molecules are tied to ozone and which are tied to greenhouse effect?

Exit Quiz

http://www.windows.ucar.edu http://maps.grida.no/go/graphic/climate-change-ice-and-snow-and-the-albedo-effect