* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Document
Low-carbon economy wikipedia , lookup
Myron Ebell wikipedia , lookup
Intergovernmental Panel on Climate Change wikipedia , lookup
Economics of climate change mitigation wikipedia , lookup
Mitigation of global warming in Australia wikipedia , lookup
Climatic Research Unit email controversy wikipedia , lookup
German Climate Action Plan 2050 wikipedia , lookup
Soon and Baliunas controversy wikipedia , lookup
Michael E. Mann wikipedia , lookup
2009 United Nations Climate Change Conference wikipedia , lookup
Heaven and Earth (book) wikipedia , lookup
Fred Singer wikipedia , lookup
Global warming controversy wikipedia , lookup
Global warming hiatus wikipedia , lookup
ExxonMobil climate change controversy wikipedia , lookup
Climate resilience wikipedia , lookup
Effects of global warming on human health wikipedia , lookup
Instrumental temperature record wikipedia , lookup
Climate change denial wikipedia , lookup
Climatic Research Unit documents wikipedia , lookup
General circulation model wikipedia , lookup
Economics of global warming wikipedia , lookup
Climate engineering wikipedia , lookup
Climate change in Australia wikipedia , lookup
Global warming wikipedia , lookup
Climate change adaptation wikipedia , lookup
Citizens' Climate Lobby wikipedia , lookup
Climate governance wikipedia , lookup
United Nations Climate Change conference wikipedia , lookup
Effects of global warming wikipedia , lookup
Climate change and agriculture wikipedia , lookup
Climate change in Tuvalu wikipedia , lookup
Politics of global warming wikipedia , lookup
Carbon Pollution Reduction Scheme wikipedia , lookup
Climate sensitivity wikipedia , lookup
Media coverage of global warming wikipedia , lookup
United Nations Framework Convention on Climate Change wikipedia , lookup
Solar radiation management wikipedia , lookup
Climate change feedback wikipedia , lookup
Climate change in the United States wikipedia , lookup
Attribution of recent climate change wikipedia , lookup
Scientific opinion on climate change wikipedia , lookup
Public opinion on global warming wikipedia , lookup
Effects of global warming on humans wikipedia , lookup
Climate change and poverty wikipedia , lookup
Climate change, industry and society wikipedia , lookup
Surveys of scientists' views on climate change wikipedia , lookup
We are now acting because the risks of inaction would be far greater. G.W. Bush’s Speech on Iraq March 16 2003 To me the question of the environment is more ominous than that of peace and war. We shall have regional conflicts and use of force, but world conflicts I do not believe will happen any longer. But the environment, that is a creeping danger. I’m more worried about global warming than I am of any major military conflict.” Hans Blix in an interview on MTV News, Reported in New York Times, Sunday March 15 2003 “Hans Blix’s Greatest Fear” Energy Balance Since 1800: Atmospheric CO2 has increased by 30% Increase in temperature // increase in greenhouse gases Climate Forcing: expressed as a change in radiative heating (W/m2) at surface for a given change in trace gas composition or other change external to the climate system Cumulative climate forcing since 1800 Hansen PNAS 2001 Forced Cloud Changes: anthropogenic aerosols may act as cloud condensation nuclei Jan 26 2001 Typical day: 700-800 planes Sep 11 2001: Air Force One + 9 military jets Jet contrails stimulated growth of cirrus clouds 5 hrs later Decreasing area of snow and ice •Signal of warming •Climate feedback: • Increase surface albedo • Increase absorption of solar irradiance • Increase temperature 1500 2000 “Forced” vs “Natural” climate change Temperature Trends Glacial-interglacial 10 K /10,000 yr = 1 K/1,000 yr AD 1000-1600: 0.9K / 600 yr = 0.15K /100 yr Cannot be ruled out AD 1980-2000: Instrumental 0.5 K / 20 years No evidence of abrupt “natural” climate change Uncertainty: natural climate variability on 102 - 103 years; abrupt climate change For the next 100 years, natural variability unlikely to exceed 0.5K Anthropogenically-forced climate change is real Climate Forcing and Climate Feedbacks: A given change in “external” climate forcing (e.g. 2xCO2) will trigger changes in the hydrologic system, atm circulation. DT_realized = feedback factor x DT_forcing Change in surface air temperature These “internal” changes will act to amplify or damp the initial forcing. CO2: 300 600 ppmv 2 1.5 1 grd albedo cld cover cld height lapse rate water vapor (z) -0.5 water vapor 0 CO2 • feedback factor ~ 3.5 0.5 -1 -1.5 veg cover sea ice water vapor + clouds -1.5 land ice -0.5 -1 •Without CO2 decrease, cannot explain cooling during the Last Glacial Maximum CO2: 300 200 ppmv 0 CO2 •Smaller feedback factor cannot explain cooling during the Last Glacial Maximum -2 -2.5 Last Glacial Maximum Energy Balance Climate Change Signal Climate Response • Warming not globally uniform • High-latitude amplification Albedo feedback Global Climate Models used to project climate change from different CO2 scenarios: Business as usual CO2 emission Stabilization of CO2 Control Holdridge Bio-Climate Classification Climate change will alter the distribution of biomes UN Framework Convention on Climate Change • Ultimate objective: stabilizing greenhouse gas concentrations in the atmosphere that would prevent dangerous anthropogenic (humaninduced) interference with the climate system • Such a level should be achieved within a time frame to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner 1988 Intergovernmental Panel on Climate Change (IPCC) estab. 1990 IPCC 1st Assessment Report real threat that by mid 21st century human actions will have changed the basic conditions that permit life Intergov Negotiating Ctte (INC) estab. 1992 UN Framework Convention on Climate Change (UNFCCC) estab; “Earth Summit in Rio de Janeiro; Convention open for signatures 1994 UNFCCC came into force: recognition that climate change is a real problem 1995 IPCC 2nd Assessment Report evidence for human-induced climate change; estimate “permissible emissions” to stabilize CO2 at 450 ppmv, 600 ppmv, ...; assessment of impacts of climate change 1997 COP3: Kyoto Protocol; developed countries to reduce their collective emissions of 6 GHG’s (from 1990 levels) by at least 5% by 2008-2012 1998 Kyoto Protocol open for signatures; 84 obtained in one year 2001 IPCC 3rd Assessment Report more evidence for human-induced climate change 2002 World Summit on Sustainable Development; Johannesburg