An international team of climate experts has taken a new look at the threat of global warming, and they do not like what they see.
The Earth will not have to warm up as much as had been thought to cause serious consequences, including more extreme weather and increasing threats to plants, animals, scientists report in this week's online edition of Proceedings of National Academy of Science.
Intergovernmental Panel on Climate Change estimated that risk of increased severe weather would rise with a global average temperature increase of between one degree Celsius and two degrees above 1990 levels. National Climatic Data Centre currently reports global temperatures have risen 0.12 degree since 1990.
Researchers now report that "increases in drought, heat waves, floods are projected in many regions and would have adverse impacts, including increased water stress, wildfire frequency, flood risks starting at less than one degree of additional warming above 1990 levels."
"It is now more likely than not that human activity has contributed to observed increases in heat waves, intense precipitation events, and intensity of tropical cyclones," concluded researchers. Other researchers suggested "likelihood of 2003 heat wave in Europe, which led to death of tens of thousands of people, was substantially increased by increased greenhouse gas concentrations."
Carbon dioxide and other gases added to the air by industrial and other activities were blamed for rising temperatures, increasing worries about possible major changes in weather and climate. Carbon emissions have been growing at 3.5 per cent per year since 2000, up sharply from 0.9 per cent per year in 1990s.
The new study says there is new evidence of greater vulnerability to climate change for specific populations, such as poor, elderly, in not only developing but also developed countries. "Events such as hurricane Katrina and 2003 European heat wave shown that capacity to adapt to climate-related extreme events is lower than expected and, as a result, their consequences and associated vulnerabilities are higher than previously thought," scientists said.