Sir: Global warming is the continuing rise in average temperature of earth’s atmosphere and oceans. The evidence for the temperature rise is unequivocal with over 90 percent certainty. Scientists have determined most of it has been caused by human activities that increase the concentration of greenhouse gases in the atmosphere, such as deforestation and burning of fossil fuels.
The instrumental temperature record shows that the average global surface temperature increased by 0.74oC during the 20th century. Human activity since the industrial revolution has increased the amount of greenhouse gases in the atmosphere. Over the last three decades of the 20th century, gross domestic product per capita and population growth were the main driver of increases in greenhouse gas emissions. Carbon dioxide emissions are continuing to rise due to the burning of fossil fuels and land use change. Rising sea levels and observed decreases in snow and ice coverage are consistent with warming. Some areas of the world will start to surpass the limit of human survivability with rises in temperature of about 6.7oC while a warming of 11.7 would in an uninhabitable environment.
Moreover, 111 countries surveyed in gallop polls determined that there was a substantial decrease in the number of Americans and Europeans who viewed global warming as a serious threat. Apart from that in United States, little over half the population; 53 percent now view it as a serious concern for either themselves or their families. Latin America had the biggest rise in concern with 73 percent saying global warming is not a serious threat to their families.
Global warming became more widely popular after 1988 when NASA climate scientist James Hasen used the term in a testimony to congress. He said global warming has reached a level that we can ascribe with the highest degree of confidence a cause and effect in the observed warming. His testimony was widely reported and afterword global warming was commonly used by the press and in public discourse. Apart from this greenhouse effect the earth average surface temperature of 15 degree Celsius would be 20 degree Celsius under which existence of life would have become impossible.
RIZWANA YOUNUS
Turbat
Published in Daily Times, December 15th 2017.