Global Warming

April 20 , 2007

Global Warming

Introduction

Climate is the average pattern of weather over the long term . For millions of years the Earth 's climate has cooled or warmed . The phenomenon is not new but our knowledge that human activity affects the Earth 's climate is new . Scientists , environmentalist , even filmmakers and fiction warn us that the global climate is warming threateningly

Several animal and plant species will not survive the climatic changes Up to 37 per cent of them would disappear by mid-21st century Scientific assessment of Arctic

climatic impacts shows that Arctic temperatures have risen by nearly twice the global average over the past fifty years and will rise 4 ?C to 7 ?C by 2100 . The rise in Arctic temperatures is dangerously impacting on human and wild life . From Russia to Canada , buildings collapsed due to subsidence caused by thawing of permafrost , Polar bears and seal fell victim to this climatic disaster . These two countries belatedly ratified the Kyoto Protocol under this climatic threat

Over the past century the global temperature increased by 0 .6 ?C to 0 .7 ?C . The 1990s were the hottest and 1998 the hottest year since the records began in 1861 . Eight hottest years since 1861 belonged to the 1990s . Glaciers everywhere are receding and sea levels rising . The 20th century recorded 10 cm to 20 cm rise in sea levels snow cover diminished by 10 per cent . Carbon dioxide levels , currently the highest are rising . Environmentalists do not believe that geographical phenomenon like the , El Nino caused this baneful increase . They blame human activity

Intergovernmental Panel on Climate Change (IPCC

There can be no room any more for skepticism on global warming "The warming of the climate system is unequivocal , as is now evident from increases in global average air and ocean temperatures , widespread melting of snow and ice , and rising global mean sea level " says a report of the Intergovernmental Panel on Climate Change (IPCC ) released on February 02 , 2007 . The report is the Summary for Policymakers of "Climate Change 2007 : The Physical Science Basis , which is the first volume of the Fourth Assessment Report (AR4 ) on climate change . The Third Assessment Report (TAR ) was issued in 2001

Relying on comprehensive data , the report states that hot extremes , heat waves and heavy precipitation events will become more frequent . Tropical cyclones will be more intense , with larger wind speeds . Rising sea level will threaten vast populations . The report summarizes the progress made in understanding human and natural drivers of climate change , observed climate change , climate processes and causes , and projections on climate change . The first volume itself , which is on the scientific basis of climate change and is the contribution of the IPCC 's Working Group I (WGI ) of about 600 authors from 40 countries , will be released in early March . The work received over 30 ,000 comments after reviews by more than 600 experts . Two other reports , one on the impacts of climate change and another on the options...