1 / 37

Global Warming

Global Warming. So What? . December 2013. WATER. FOOD . Rainfall becomes more variable. Planet-wide, we get a little more rain. Around the Arctic gets lots more, mid-latitudes (20-40°) less. . Yet in any one place, we get more hours and days without rain . In other words,

jessica-mcgowan
Download Presentation

Global Warming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Global Warming So What? . December 2013

  2. WATER FOOD . Rainfall becomes more variable. Planet-wide, we get a little more rain. Around the Arctic gets lots more, mid-latitudes (20-40°) less.. Yet in any one place, we get more hours and days without rain. In other words, we get more downpours and floods, yet also longer, drier, hotter droughts.

  3. Droughts Worsen . Evaporation increases. Droughts Worsen.

  4. ~ means “approximately, roughly, is about equal to” 1°C = 1.8°F. One MW can power several hundred US homes. Earth Is Heating Up (±75 million MW) • Earth now absorbs 0.25%more energy than it emits - a 300 million MW heat gain. This absorption has been accelerating, from near zero in 1960. 300 million MW • Airat the land surface is 1.1°Cwarmerthan 100 years ago. Half that warming happened in the last 33 years. Earth will warm another 0.6°C, • Airat the sea surface is 0.8°C warmerthan 100 years ago. • The oceans have gained ~10 x moreheat in 40 years than ALL the energy humans have EVER used. = 20x human energy use. = 70 x globalelectric supply so it emits enough heat to balance absorption.

  5. Tipping Points Report to US & British Legislators - January 2006 What would make climate change accelerate, so natural forces defeat our efforts to slow it? Disappearance of sea ice means more heat is absorbed by the water below. Carbon sinks fade, fail, and even reverse in oceans & forests. 3 Methane release from permafrost revs up warming in a vicious circle.

  6. Water Hurricanes convert ocean heat to powerful winds & heavy rains. Intense hurricanes are becoming more common. Higherhurricane energy closely tracks sea surface warming. With more carbon, oceans have grown more acidic. So, forming shells is more difficult. They dissolve easier. Warmer water holds less dissolved oxygen. Fish & mollusks suffer. Oceans warmed 0.15°C over 1997-2004, so planktonabsorbed 7% less CO2. Warming was far strongest in the North Atlantic. CO2 uptake therefell by half. Ocean phytoplankton levels are down 40% since the 1950s. Phytoplankton supply half of Earth’s oxygen. More Heat - So?

  7. Reservoirs in the Sky Most mountain glaciers dwindle ever faster: in the Alps, Andes, Rockies, east & central Himalayas. When Himalayan glaciers vanish, so could the Ganges River in the dry season. Mountain snows melt earlier. CA’s San Joaquin River (Central Valley, US “salad bowl”) could dry up by July in most years. The Colorado River’s recent 10-year drought was the worst since white men came.

  8. Earth’s Thermostat Greenland’sice-melt rate rose5 xover the past 15 years. Its net melt-water already ~ US water use. The situation is similar in Antarctica... Arctic Oceaniceis shrinking fast, . Minimum icepack area fell 37% in 34 years, while its minimum volume fell 72%, It could vanish by fall in 4 years Sea level will likely rise 1-7 feet by 2100 Thawing Arctic permafrost holds6xthecarbon ever emitted by our fossil fuels = 2 x the carbon in Earth’s atmosphere. Already, permafrost’s carbon emission rate ~ that from all US vehicles. Thawing permafrost can add ~100ppm of CO2 to the air by 2100, and almost 300 ppm more by 2300. Seabed methane hydrates& Antarctica hold much more carbon. especially in 2012. 53% in the last 10. & be gone all summer in 10. & far more afterward.

  9. Hot & Dry From 1979 to 2005, the tropics spread. . Sub-tropic arid belts grew ~140 miles toward the poles, . a century ahead of schedule. . That means our jet stream moves north more often. In turn,the US gets hot weather more often. 2011-12 was America’s hottest on record. . Over September 2011 - August 2012, relative to local norms, 33 states were drier than the wettest state (WA) was wet. In 2012,44 of 48 states were drier than normal... Severedrought covered a record 35-46% of the US . Drought reduced the corn crop by a quarter. Record prices followed. The soybean crop was also hit hard. By 2003, forestfires burned 6 x as much area / year as before 1986. Pine bark beetles ravage forests. . . What Else? , for 39 weeks. US fires will double by 2050.

  10. Notable Recent Droughts When I was young, the leading wheat producers were the US Great Plains, Russia’s steppes, Canada, Australia, and Argentina’s Pampas. . When Where How Bad 2003 Europe record heat, 20-70 thousand die 2003-10 Australia worst in millennia 2005 Amazon Basin once a century 2007 Atlanta, SE US once a century 2007-9 California emergency, record low rain in LA 2008-9 Argentine Pampas worst in half century 2008-11 North China ~ worst in 2 centuries 2009 India monsoon season driest since 1972 2010 Amazon Basin worse than once a century 2010 Russia record heat & forest fires 2011 Texas, Oklahoma record heat & drought 2012 US: SE, SW, MW most widespread in 78 years

  11. Is That All? No .. Over 1994-2007, desertsgrew from 18 to 27% of China’s area. With more evaporation & irrigation, many water tables fall .. Since 1985, half the lakes in Qinghai province (China) vanished. 92% in Hebei (around Beijing). Irrigation wells chase water ever deeper. Water prices rise. Inland seas and lakes dry up& vanish: the Aral Sea, Sea of Galilee, Lake Chad (Darfur), Lake Eyre. More riversfail toreach the sea: the Yellow,Colorado, Indus, Darling Rivers so far. Water 3-20 feet/ year.

  12. • Switch from what could happen to what has happened already. Droughts Are Spreading Already. 30% = 16 million square miles combined effect 10 million more square miles Compare 2002 to 1979. 11% of the area during 1951-80 once per 9 years Area whererain is scarce increased by quite a bit: 3-5 million square miles. Evaporation increased, by a lot since 1987. Evaporation at work Earth’s area in severe drought hastripledsince 1979. Compare 30% actual severe drought in 2002 to 27% projected. from Fig. 9 in Aiguo Dai, Kevin E. Trenberth, Taotao Qian [NCAR], "A Global Dataset of Palmer Drought Severity Index for 1870-2002: Relationship with Soil Moisture and Effects of Surface Warming,” Journal of Hydrometeorology, December 2004, 1117-1130 Correspondingly wet areas, 1979-2002, fell, from 11% to 8%. Evaporation trumped rainier.

  13. SUMMARY Severedroughthas arrived, Severe droughtnow afflicts an area the size of Asia. So, farmers mine groundwater ever faster for irrigation. From 1979 to 2002 (+0.5°C) . 1) The area where rain is scarce increased by the size of the United States. Add in more evaporation.. 2) The area with severe drought grew by the size of North America. 3) The area suffering severe drought tripled. 4)The similarly wet area shrankby the size of India. as projected or faster.

  14. Turning Wheat into Cactus . In 2005-6, scientists calculated how climate would change for 9 Northeast and 6 Great Lakes states in 2 scenarios: #1 - a transition away from fossil fuels, or #2 - continued heavy reliance on them (business as usual emissions). By 2085, averaged across 15 states, the climate change would be like moving 330 miles to the SSW (coal & oil use dwindle), or moving 650 miles to the SSW (heavy coal & oil use). Consider central Kansas, heart of wheat country. 330 miles to the SSW lies the area from Amarillo to Oklahoma City. 650 miles to the SSW lies the area around Alpine & Ft. Stockton, Texas. 2 people / square mile. Cactus grows there. Mesquite & sagebrush too. No wheat

  15. • ExtremeDroughtCanClobberEarth • In 1989, NASA climate models showed, as CO2 levels rise and Earth warms up, droughts would spread and intensify. • “Once-per-9-year” droughts would cover 27% of Earth by 2002. • With business as usual emissions, by 2059 CO2 levels would double pre-industrial levels. • As a result, Earth would warm 4.2°C [7.5°F] from 1880 levels. Rain would increase 14%. • Despite the added rain, increased evaporation would bring extreme “once-a-century”drought to 45% of Earth, & rising. WET DRY 0 1 5 16 36 36 16 5 1 0 % Occurrence in Control Run Fig. 1d in David Rind, R. Goldberg, James Hansen, Cynthia Rosenzweig, R. Ruedy, “Potential Evapotranspiration and the Likelihood of Future Droughts,” Journal of Geophysical Research, Vol. 95, No. D7, 6/20/1990, 9983-10004. .

  16. What Drives Drought? The water-holding capacity of air rises exponentially with temperature. Air 4°C warmer holds 33% more moisture at the same relative humidity. . more moisture in the air does not equal more clouds. To maintain soil moisture, ~10% more rain is required to offset each 1°C warming. Warmth draws more water UP (evaporation), so less goes DOWN (into soils) or SIDEways (into streams). Morewater isstoredin theair,lessinsoils. Not all the water that goes up comes back down. Thus,

  17. Droughts - Why Worry? . Droughts - Why Worry? 2059 - 2 x CO2 (Business as Usual Emissions) . More moisture in the air, Average US stream flows decline 30%, Tree biomass in the eastern US falls by up to 40%. More dry climate vegetation: The vegetation changes mean • Biological Net Primary Productivity falls 30-70%. SWITCH from PROJECTIONS to ACTUALS. . • Satellites show browning of the Earth began in 1994. . Rind et al., 1990 but 15-27% less in the soil. despite 14% more rain. savannas,prairies, deserts Fung 2005 Zhao 2010

  18. Crop Yields Fall. United States: 2059 Projections - doubled CO2 - Business as Usual Great Lakes, Southeast, southern Great Plains Corn, Wheat, Soybeans 2 Climate Models (Scenarios) . NASA GISS Results Goddard Institute for Space Studies Yieldsfall30%, averaged across regions & crops. NOAA GFDL Results Geophysical Fluid Dynamics Lab Yieldsfall50%, averaged across regions & crops. CO2 fertilization not included . So things won’t be this bad, especially this soon. Temperature effects of doubled CO2 will keep growing - eventually to 4.2° or 4.5°C - but over many decades, even after 2100. CO2fertilization boosts yields 6-30% or more in experiments, where water and other nutrients are well supplied, and weeds and pests are controlled. That won’t happen as well in many fields. Groundwater and snowmelt for irrigation grow scarcer in many areas. Other factors (esp. nitrogen) can limit growth. CO2 fertilization has diminishing returns. Rind et al., 1990 - 3 of the big 4 crops (rice is the 4th) (based on 4.2°C warmer, 14% more rain) (based on ~ 4.5°C warmer, 5% less rain)

  19. Photosynthesis, Warming & CO2 . Plants evaporate (transpire) water in order to [like blood] get it up to leaves, where H2O & CO2 form carbohydrates, pull other soil nutrients up from the roots to the leaves, and [like sweat] (3) cool leaves, so photosynthesis continues & proteins aren’t damaged. When water is scarce, fewer nutrients (nitrogen, phosphorus, etc.) get up to leaves. So, with more CO2, leaves make more carbohydrates, but fewer proteins.

  20. Warming & Falling Yields . For wheat, corn & rice, photosynthesis in leaves slows above 35°C (95°F) and stops above 40°C (104°F). Warming(above 35° or 40°C) hurts warm, tropical areasharder& sooner. Over 1992-2003, warming above the norm cut corn, rice & soybean yields by ~10% / °C. Over 1982-98, warming in 618+ US counties cut corn & soybean yields ~17% / °C. With more CO2, 2°C warming cut yields 8-38% for irrigated wheat in India. Warmer nights since 1979 cut rice yield growth 10%± in 6 Asian nations. Warming since 1980 cut wheat yield growth 5.5%, corn 3.8%.

  21. Heat Spikes Devastate Crop Yields Heat Spikes Devastate Crop Yields Schlenker & Roberts 2009 Average yields for corn and soybeans could plummet 37-46%by 2100 with the slowest warming and 75-82%with quicker warming. Why? Corn and soybean yields rise with warming up to 29-30°C, but fall more steeply with higher temperatures. Heat spikes on individual days haveBIG impacts. More rain can lessen losses. Plants transpire more water to cool off. Growing other crops, or growing crops farther north, can help too.

  22. UN Chief on Climate Change . Some scientists are saying publicly that if humanity goes on with business as usual, climate change could lead to the collapse of civilization, even in the lifetime of today's children. United Nations Secretary General Ban Ki-Moon said “I think that is a correct assessment.” He added carefully “If we take action today, it may not be too late.” September 24, 2007

  23. Food Price Index . Poor people could not afford to buy enough food in 2007-8. . Malnutrition & starvation rose. Food riots toppled governments in 2011. and 2010. With food stocks at low levels, food prices rose steeply in 2007-8 2002-04 = 100 UN, Food & Agriculture Organization: World Food Situation / FAO News Ditto 2010-11.

  24. • World Food Prices . Over 2005-7, . world prices . rose 125% . for wheat, . 100% for corn, . 27% for rice.+. soybeans 83%. in just 1 year.. Look at 2008.. Over 2006-7, . food prices rose . 18% in China, . 13%inIndonesia. & Pakistan, . 10+% in India, . Russia & . Latin America. . Over 2007-8, world food prices rose20-150%.. In the US, food prices rose too: whole wheat bread 12%, milk 29%, eggs 36%. Why? Grain for ethanol, High oil prices UN: Food & Agriculture Organization Rice Wheat Corn 2012 2009 2013 2008 2011 2010 2007 more meat for China, droughts in Australia, Ukraine, Russia ,devalued $. mean more $ for fertilizer & pesticides, & especially to fuel pumps & tractors.

  25. 2° vs 4° Warming . 1.1°C warming is here. Holding warming to 2°C, not 4°, prevents these losses: 3/4 of Gross World Product $42 Trillion ~ 3/4 of GWP 1/5 of the World’s Food . 2/3 of Amazon Rainforest 1/8 of the world’soxygensupply Gulf Stream + West Antarctic Icecap . Florida & Louisiana, central CA, Long Island, Cape Cod 1/2 of all Species . 2°C warming is manageable. Details to follow: first 2°C, next 3°, then 4°, finally 5°C. 2°C has become unavoidable. - Norfolk area, much of 4°Cthreatens civilization itself.

  26. 2°C Warming - 450 ppm CO2e*.. (Waxman-Markeybill or Kerry-Boxerbill in Congress) . Stern Review, British government, Oct. 2006 . (a report by scores of scientists, headed by World Bank’s chief economist) . selected effects - unavoidable damages. Hurricane costs double. Major heat waves are common. Droughts intensify. Civil wars & border wars over water increase: Crop yieldsrisenowhere, fall in the tropics. Greenland icecap collapsebecomes irreversible. The Ocean begins its invasion of Bangladesh. * also includes CH4, O3, SO4, etc. Many more major floods Forestfires worsen. Deserts spread. moreDarfurs.

  27. 3°C Warming - 550 ppm CO2e (McCain-Lieberman bill, watered down) additional damages – avoidable Droughts & hurricanes get much worse. Hydropower and irrigation decline. Crop yieldsfallsubstantiallyin many areas. More water wars & failed states. 2/3ofAmazonrainforestmayturntosavanna,desertscrub. Tropical diseases (malaria, etc.) spread farther & faster. 15-50%of species face extinction. Stern Review + Water is scarce. Terrorists multiply.

  28. .4°C Warming - 650 ppm CO2e.. (double pre-industrial levels) (Bush proposal) further damages - avoidable • Water shortages afflict almost all people. Crop yieldsfallinALLregions,by1/3inmany. Entire regions ceaseagriculturealtogether. Water wars, refugee crises, & terrorism become intense. Methane releasefrom permafrost accelerates. The Gulf Stream may stop, monsoons often fail. West Antarctic ice sheet collapse speeds up. Stern Review

  29. 5°C Warming . 5°C Warming - 750 ppm CO2e (Business as Usual Emissions) . Deserts GROW by 2 x the size of the US. World food falls by 1/3 to 1/2. Human population falls. to match the reduced food supply. Other species fare worse. We may hit 5°C by 2100. my extrapolations a lot,

  30. The Stakes . The costs of failing to tackle the climate change issue would be greater than the impact of both World Wars and the Great Depression combined. Once the damage from unchecked emissions growth is done, no retrospective global agreement, in some future period, can undo that choice. British Prime Minister Gordon Brown October 19, 2009

  31. CO2 Emission Paths to Stabilization . • Stern Review CO2e (CO2 equivalent) includes warming from CO2 & other GHGs, less the cooling effect of sulfates. -32% Total Warming +3°C -67% -75% +2°C The paths assumeNOemissions frompermafrostor seabedmethanehydrates. Holding eventual warming to 2°C, above 1750 levels, will be challenging. We are already at 445 ppm CO2e (including 395 of CO2). 450 is not far. 445 ppm CO2e = 395 CO2 + 311 other GHGs - 261 sulfate cooling.

  32. • World CO2 Emissionsfrom Fossil Fuels31.8 Billion Tons in 2010 US DOE / EIA . . . In 2012, US fossil fuel CO2 comes 42% from oil, 29% from coal, 29% from natural gas. 35% comes from electricity, 33% from transportation, 17% from industry. * Misc. = Korea, Indonesia, Thailand, Taiwan, Malaysia, Vietnam, Bangladesh, etc.

  33. • CO2 Cap Bills in Congress . US CO2 Reduction Paths: Bills in Congress +5°C Business as Usual Bush proposal, 2008 +4°C McCain / Lieberman (S) ACTUAL +3°C assumes other nations do their part too. New York Times, NRDC, World Resources Institute; House Commerce Committee; Senate Environment & Public Works Committee Waxman-Markey (H) +2.2°C Kerry / Boxer (S) 80% Reduction +2.0°C Take huge amounts of carbon OUT of the air TOO. Graze cows in skillful rotation, to bury carbon in soils. Speed up rock weathering 50,000 X. Biochar Farm the oceans, sink algae harvest. Pump carbon-rich surface water to deep ocean.

  34. • US CO2 Emissions, by Use . Concentrate on the BIG stuff: coal for electricity (with a carbon cap)&personal transportation. * Trucks, airlines, railroads, buses, pipelines, ships 2012: USDOE - EIA (US Department of Energy - Energy Information Administration)

  35. US Electricity, by Source & Yr .

  36. America’s Low-Carbon Revolution Has Begun US DOE / EIA US DOE / EIA Net Imports US DOE / EIA US DOE / EIA

  37. QUESTIONS ContactDr. Gene Fry for more details, citations & references. gene.fry@rcn.com www.globalwarming-sowhat.com

More Related