"Supervillain" CO2 has "henchmen" like NO2 and methane

There are harmful greenhouse gases like nitrous oxide (N2O) and methane, which are the "henchmen" of CO2.

Last Updated: Sep 09, 2009, 17:48 PM IST

Washington: Scientists have said that in the fight against global warming, "supervillain" carbon dioxide (CO2) should not be solely targeted, as there are harmful greenhouse gases like nitrous oxide (N2O) and methane, which are the "henchmen" of CO2.
According to a report in National Geographic News, several "henchmen" gases-some even more potent than CO2-have also been building up in Earth`s atmosphere.

For now, none of these gases is as big a worry as CO2, due to its higher levels in the atmosphere.

But if left unchecked, experts warn, these other compounds could create major new climate change battlefronts.

"The truth is we don`t really have room for these gases to grow, in terms of the state that we are in with climate change," said Jay Gulledge, a senior scientist at the Pew Center on Global Climate Change in Arlington, Virginia.

"It is happening more rapidly than (it was) projected to happen," he added.

Most recently scientists warned that nitrous oxide, also known as laughing gas, already accounts for roughly 6 percent of the gases that fuel human-caused climate change.

The main culprit is animal manure, which releases N2O into the atmosphere, according to a new study by Eric Davidson, a senior scientist at the Woods Hole Research Center in Falmouth, Massachusetts.

Nitrous oxide emissions are first produced when fertilizer is added to the soil to grow animal feed.

Animals then concentrate nitrogen inside their feces and urine, and soil microbes interact with the released waste to create N2O.

Burning fossil fuels, manufacturing nylon, and other industrial activities also emit the greenhouse gas.

"If we just go on with business as usual with increasing food production, particularly increasing meat production, nitrous oxide will become an even bigger problem," Davidson said.

Manure management should therefore be part of future plans to combat climate change, the scientist concluded.

In addition to laughing gas, scientists have their eyes on methane, the second largest contributor to climate change.

Methane accounts for about 15 percent of the warming that has occurred in the past century, Gulledge noted, and is 20 to 25 times more powerful than carbon dioxide.

"There is a potential for large amounts of methane to be emitted from natural systems as they warm," he noted.

The other worrisome greenhouse goons are synthetic gases used as refrigerants, in heavy industry, and in consumer electronics.

Many are replacements for chlorofluorocarbons, or CFCs, which were phased out from sources such as refrigerators and air conditioners in the 1990s to prevent destruction of the Earth`s ozone layer.