5 June 2006
– Sampurna Lata Tuladhar
“We cannot see a single drop of rain in this rainy season”; “It should be warm till this month but it is still too cold”; “For the first time in my life I see it’s raining in this season”, “Crops are damaged because of the unusual heavy rain”, “Farmers are not getting able to plant crops on time because of the drought”. We hear these versions very often and the news on such issues. The reason is the climate change. Climate is changing because effect of global warming is getting high.
Earth was freezing cold long time ago. There was no possibility of surviving in it. Earth began to warm slowly and then the possibility to live in earth grown up. It is because of the Greenhouse Gases or Greenhouse Effect. Greenhouse gases are components of the atmosphere that contribute to the Greenhouse effect.
In botanical parks, we see Greenhouses, made for special purpose. Once sunlight enters a greenhouse, it traps the heat. The same way atmospheric greenhouse gases absorb heat and as a result, temperature rises. Naturally occurring greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone.
In the 20thcentury, temperature of the Earth increased by 0.6oC. The 1990s were the hottest decade of the entire century. 1998, 2001, and 2002 were three of the hottest years ever recorded. This is largely the result of emissions of greenhouse gases from human activities including industrial processes, fossil fuel combustion, and deforestation. Projections of future warming suggest an increase of 1.4oC to 5.8oC by 2100.
Global warming is an extraordinary challenge. The world’s leading atmospheric scientists say “Gradual warming of our climate is underway and will continue”. This long-term warming trend leads serious risks to environment. It poses even greater risks to poorer countries like Nepal that will be far less able to cope with a changing climate.
There is no certainty in how the climate system varies naturally and reacts to emissions of greenhouse gases. Better awareness and understanding of the buildup of greenhouse gases in the atmosphere and the behavior of the climate system is necessary to make progress in reducing uncertainties in projections of future.
By : Sampurna Lata Tuladhar