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
Amongst the following Green House Gases (GHGs), whose Global Warming Potential (GWP) is considered as 1?
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.
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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 :Full form of IPCC, a nodal agency in the context of climate change, is:
Given below are two statements
Statement I: Increased carbon dioxide concentration in the ambient atmosphere is likely to make the world's oceans less acidic.
Statement II: Increased carbon dioxide concentration in the ambient atmosphere is likely to impact the coral reefs adversely.
In light of the above statements, choose the correct 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?
In terms of total $CO_2$ emissions from a country, identify the correct sequence:
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Important Questions from Climate Change & Global Warming
Greenhouse gas, which is present in the highest quantity in the atmosphere, is
Which one of the following gases have higher Global Warming Potential?
Which of the following two sources of carbon is released?
A) Volcanic eruption
B) Combustion of fossil fuels
C) Landslide
D) Open mining
Choose the correct answer from the options given below:
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?
