Threat of methane-laden air looms large

Scientists have been warning about the impending  natural disaster due to man's quest to produce energy through conventional means as it is bound to increase greenhouse gas emissions. 

However, some western countries have taken this as a serious concern due to the mounting pressure from the environmentalists. A new analysis of the latest studies on trace gases trapped in Antarctic ice core provide fresh evidence that greenhouse gases concentrations of carbon dioxide and methane have never been as high during the last 800,000 years as today, according to researchers.

Methane (CH4) is the primary component of natural gas and an important energy source. Methane is also a greenhouse gas, meaning that its presence in the atmosphere affects the Earth's temperature and climate system.

Methane is one of several greenhouse gases that contribute to global climate change. Human influenced sources include landfills, natural gas and petroleum systems production and distribution, agriculture, coal mining, combustion, wastewater treatment, and certain industrial processes. Natural sources include wetlands, termites, oceans, and hydrates.

The historical record, based on analysis of air bubbles trapped in ice sheets, indicates that methane is more abundant in the Earth's atmosphere now than at any time during the past 400,000 years (IPCC, 2001). Over the last two centuries, methane concentrations in the atmosphere have more than doubled.

However, in the past decade, while methane concentrations have continued to increase, the overall rate of methane growth has slowed (Dlugokencky et al, 2003). Given our incomplete understanding of the global methane budget, it is not clear if this slow down is temporary or permanent.

"The fundamental conclusion that today's concentrations of these greenhouse gases have no past analogue in the ice-core

record remains firm," says an associated professor of geosciences at the Oregon State University Edward Brook who wrote a commentary for the Nature magazine on new studies.

"The remarkably strong correlations of methane and carbon dioxide with temperature reconstructions also stand," he says.

The latest research, done by members of the European Project for Ice Coring in Antarctica, extend the data on trace gases back another 150,000 years beyond any studies done prior to this, Brook said. Ultimately, researchers would like to achieve data going back as much as 1.5 million years.

Scientists are carefullyr monitoring its impact in the atmosphere. Regardless of the source of methane -- whether human-produced or natural -- data on why, how much, and where methane is being emitted are being used to complete the picture of assessing the role of methane in the Earth system.

Over the last two centuries, methane concentrations in the atmosphere have more than doubled, although the rate of growth of methane in the atmosphere has slowed in the last decade (Dlugokencky et al, 2003).

Scientists are measuring the amount of methane in the atmosphere, where it is coming from and where it goes, and modeling its behavior to try to understand the effects of increased levels of methane in the atmosphere.

US government has taken several model steps to counter the adverse impact of the emission including guideline to the common man. Because of these programs to reduce atmospheric methane concentrations have led to emissions reductions of about 10 percent below 1990 levels (EPA, 2005).

These voluntary programs have targeted methane reductions in coal mining, landfills, oil and natural gas systems, and agriculture by more effectively capturing methane during fossil-fuel extraction, capturing methane from landfills, and reducing biomass burning.