Which one of the following green house gases has the shortest residence time in the atmosphere?
Methane
Residence time, also called atmospheric lifetime, is the average length of time a molecule of a gas remains in the atmosphere before it is removed by chemical reaction or absorption. Comparing the four gases on this measure gives a clear ordering.
Methane has the shortest residence time, roughly twelve years. It is destroyed in the troposphere by reaction with hydroxyl radicals, which oxidise it eventually to carbon dioxide and water. This relatively rapid removal is why methane is often described as a short lived climate pollutant, and why cutting methane emissions produces climate benefits within decades rather than centuries. It is a potent gas while it lasts, with a global warming potential many times that of carbon dioxide over a twenty year horizon.
Nitrous oxide lasts far longer, of the order of a hundred and fourteen years. It is chemically stable in the troposphere and is removed mainly by photolysis in the stratosphere.
Chlorofluorocarbons are extremely stable, with lifetimes ranging from about forty five years to more than a century depending on the compound. That stability is exactly why they survive long enough to reach the stratosphere and destroy ozone there.
Carbon dioxide is the special case. It has no single lifetime, because it is not destroyed by a chemical reaction but exchanged among the atmosphere, oceans and biosphere. A large fraction is absorbed within decades, but a substantial part remains for centuries and some for thousands of years, which is why carbon dioxide emitted today continues to warm the planet long after it is released.
Hence methane has the shortest residence time in the atmosphere.
Similar Questions
Given below are two statements :
Statement I : In many cases, both organisms and human infrastructure will not be able to move or adapt quickly enough to changing climate.
Statement II : Infectious diseases are likely to increase as a result of global warming.
In the light of the above statements, choose the most appropriate answer from the options given below :Suppose the concentration of Carbon dioxide, a greenhouse gas responsible for climate change, is 400 ppm. What is its concentration in air in percentage terms?
How many National Missions of the Indian Government are there to address the problem of climate change?
Full form of IPCC, a nodal agency in the context of climate change, is:
India's contribution to total global carbon dioxide emissions is about:
Consider the following statements :
(a) Earth would be safer without greenhouse effect
(b) Major contribution to the greenhouse effect comes from carbon dioxide
(c) Earth’s climate was changing even before man appeared on earth
Which of the above statements are correct?
Which of the two following is the correct sequence of greenhouse gases according to their relative global warming potential in increasing order?
In order to avoid catastrophic consequences of climate change, there is general agreement among the countries of the world to limit the rise in average surface temperature of earth compared to that of pre-industrial times by
In the context of climate change which of the following observations are correct for 20th century with reference to 1750?
A. The global average surface temperature has increased by 0.6°C.
B. Greater increase in daytime temperature than night time has been observed.
C. Global average sea level rose 0.1-0.2 m largely due to thermal expansion.
D. The atmosphere concentration of Carbon dioxide (CO2) has increased by 31%.
E. Precipitation in the northern hemisphere has decreased by 1% per decade.
Choose the correct answer from the options given below:In terms of total $CO_2$ emissions from a country, identify the correct sequence:
Important Questions from Climate Change & Global Warming
Considering the global warming potential of CO 2as one, the global warming potential of CH 4has been estimated to be approximately :
Which of the following gas is not involved in the production of acid rain?
Which of the following gas has the highest Global warming potential (GWP)?
In 'global warming' the temperature of
- Consider the following evidences that supports the theory of gradual rise in air temperature and consequent global warming.
A. Warming of ocean water at global level
B. Temperature records
C. Rise in sea levels
D. Freezing of mountain glacier and melting of continental glaciers.
Choose the most appropriate answer from the options given below :
