POLICY FORUM Uncertainties in Projections of Human-Caused Climate Warming
نویسنده
چکیده
Mankind's actix~itieshave increased carbon dioxide (CO?) in the atmosphere. This increase has the potential to warm the earth's climate by the "greenhouse effect" ( 1 ) in which COz ahsorbs infrared radiation and then re-radiates it back toward the surface of the planet. Other gases also act as greenhouse gases and may warm the climate ex7en further (Z),although human-produced airborne sulfate particles can cause cooling that offsets some of the warming (3). Computational models that include these factors predict that the climate will warm significantly over the next century. These forecasts of likely climate changes have forced a realization that it is necessary to reduce human-caused emissions of greenhouse gases. But hecause of the potential social disruntions and hieh economic costs of such reductions, vigoro~~s dehate has arisen ahout the size and nature of the proiected & ,
منابع مشابه
Climate Change: The Uncertainties, the Certainties, and What They Imply About Action
Economists’ Voice www.bepress.com/ev July, 2007 © The Berkeley Electronic Press F irst the uncertainties; then the certainties; then the urgencies; and finally, what do uncertainties imply about waiting for their resolution before acting. The uncertainties are many and great. How much carbon dioxide may join the atmosphere if nothing is done about it? That depends on projections of population, ...
متن کاملWhen Could Global Warming Reach 4°c? When Could Global Warming Reach 4°c?
The IPCC Fourth Assessment Report (AR4) assessed a range of scenarios of future greenhouse gas emissions without policies to specifically reduce emissions, and concluded that these would lead to an increase in global mean temperatures of between 1.4°C and 6.9°C by the end of the 21st Century, relative to pre-industrial. While much political attention is focussed on the potential for global warm...
متن کاملWhen could global warming reach 4°C?
The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) assessed a range of scenarios of future greenhouse-gas emissions without policies to specifically reduce emissions, and concluded that these would lead to an increase in global mean temperatures of between 1.6°C and 6.9°C by the end of the twenty-first century, relative to pre-industrial. While much political at...
متن کاملPalaeoclimatic insights into future climate challenges.
Palaeoclimatic data document a sensitive climate system subject to large and perhaps difficult-to-predict abrupt changes. These data suggest that neither the sensitivity nor the variability of the climate are fully captured in some climate-change projections, such as the Intergovernmental Panel on Climate Change (IPCC) Summary for Policymakers. Because larger, faster and less-expected climate c...
متن کاملPredicting future uncertainty constraints on global warming projections
Projections of global mean temperature changes (ΔT) in the future are associated with intrinsic uncertainties. Much climate policy discourse has been guided by "current knowledge" of the ΔTs uncertainty, ignoring the likely future reductions of the uncertainty, because a mechanism for predicting these reductions is lacking. By using simulations of Global Climate Models from the Coupled Model In...
متن کامل