Statements from the IPCC 3rd Assessment - 2001"An increasing body of observations gives a collective picture of a warming world and other changes in the climate system."There is new and stronger evidence that most of the observed warming over the last 50 years is attributable to human activities. - It is now considerably clearer than at the time of the Second Assessment Report in 1995 that the addition of greenhouse gases to the atmosphere by humanity - the largest portion of which is the burning of fossil fuels - is changing the global climate. - 20th century trends of increasing temperature, sea-level rise, and increased precipitation will continue and intensify in the 21st century. - The anticipated increase in temperature over this century has increased from a range of 1 - 3.5° C in the Second Assessment Report, to 1.5 - 6°C. - The anticipated range of global sea level rise is now between 14 and 80 cm, with a mid-range estimate of about half a meter. - There is likely to be an increase in extreme weather events such as heat waves, increased precipitation leading to floods, and higher minimum temperatures and fewer cold days. - Glaciers and polar ice are set to continue melting, and there will be a continued decrease in Northern Hemisphere snow and ice cover. - Climate change will persist for many centuries, due to the long life of greenhouse gases in the atmosphere and the long time required for transfer of heat from the atmosphere to the deep oceans; even with quick action to curtail emissions, the effects of our current activity will be felt for hundreds of years. - While it is not expected to happen in this century, current rates of increase in greenhouse gas emissions may commit us to the eventual melting of the Greenland ice cap and/or the West Antarctic Ice Sheet, either of which could add around six meters to global sea level, with catastrophic effects. Recent regional changes in temperature have had discernible impacts on many physical and biological systems. Current rates of human-induced climate change: - Risk large scale and irreversible impacts, such as the melting of the Greenland and Antarctic ice sheets, the shutting down of the Gulf Stream, and massive releases of greenhouse gases from melting permafrost and dying forests. - Will have severe impacts on a regional level. For instance, in Europe, river flooding will increase over much of the continent; and in coastal areas, the risk of flooding, erosion and wetland loss will increase substantially. - Will have the greatest impacts on those least able to protect themselves from rising sea levels, increase in disease and decrease in agricultural production in the developing countries in Africa and Asia. Hundreds of technologies at very low cost are already available to reduce climate damaging emissions, but government policies are needed to remove the barriers to those technologies. - -Using known and currently available technologies global greenhouse emissions can be reduced below year 2000 levels in period 2010-2020 at zero net costs, with at least half of this achievable at negative costs e.g. at a profit. - Modeled costs, not taking into account the benefits of greenhouse gas reductions, in the industrialized countries of meeting their emission reduction targets under the Kyoto Protocol, including using emission trading are quite low, equivalent to 0.1 to 1.1% of projected GDP in 2010. This is equivalent to costs of up $125 US per capita per year in the OECD, while the projected increase in GDP per capita over that period is US$ 3000-5000 per year above today's levels. - -Using a conservative estimate and with no new technological breakthroughs, it is possible to stabilize carbon dioxide concentrations in the atmosphere at relatively low levels. However government policies to put in place energy efficient technologies and to introduce more rapidly low or no-carbon energy supply technologies are needed if this is to be achieved. |
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