V Ramanathan Wilson Center, DC March 17,2010 US-India Role in Climate Change and Air Pollution Sources of greenhouse Gases and Aerosols in Brown Clouds. Ramanathan 2007 Global Atmosphere Ramanathan 2007 Source: Washington, NCAR, 2005 Committed warming derived from IPCC Forcing & IPCC climate sensitivity The Copenhagen Accord for Limiting Global Warming: Criteria, Constraints and Available Avenues Ramanathan and Xu, Submitted to PNAS, 2010 CO2 reductions have to be complemented with Reductions in short-lived non-CO2 warming agents Even with 50% reductions by 2050, CO2 will Increase to 440 PPM; Commit another 1 C warming .. Total additional investment needs in technology and deployment between now and 2050 would amount to USD 45 trillion, or 1.1% of average annual global GDP over the period, IEA, 2008 Intl Energy Angecy Report Non-CO 2 climate warmers Contribution to 2005 forcing relative to CO 2 (1.66 Wm -2 ) Ref: Forster, Ramaswamy et al, WG1-AR4, IPCC, 2007 Greenhouse Gases Ozone (troposphere) : 20% Methane : 30% Halocarbons : 20% Particles (Aerosols) Black Carbon : 27% to 55% * (soot/smoke) _________________________________________ Total Non-CO 2 : 97% to 125% _________________________________________ All numbers except the red are IPCC values; Long lived N 2 O not included * Ramanathan & Carmichael; 2008 November December Ramanathan 2007 NASA-MODIS Ramanathan 2007 Satheesh &Ramanathan, 2000 CALIPSO Aerosol Depth: Ramanathan et al, Nature, 2007 Masking of Global Warming: 2002 {A Synthesis of ground, aircraft and satellite observations} Chung, Ramanathan, Kim, Podgorny,2005 Forcing GHGs = 3 ABCs = -1.4 (+-50%) Dimming : Mirrors & BC Heating of Blanket by BC & Others Hindu Kush-Himalayan-Tibetan Glaciers: Water Fountain of Asia Observed Trends in Summer Rainfall: 1950 to 2002 The Sahelian Drought The Weakening Indian Monsoon N-S Shift in Asian rainfall Major Rainfall Shifts during the last 50 Years Chung and Ramanathan 2006 Emission Cumulative Emission Kg/Capita Emissions (Tg/yr ) BC emission BC Emission/Capita Ref: Ramanathan and Feng, 2008; Data source: Bond et al 2004 1975 Zaelke Economist, Dec