Atmospheric tests that have covered the entire United States come up with methane emissions that are about 50 percent higher than the EPA estimates, according the new paper in Science. The air sampling studies , though, have found some odd peaks in regional methane emissions, causing scientists to worry that there could be a lot more methane leaking from sites of natural gas production than thought. So Brandt and his colleagues began tallying up all the places where natural gas production could be leaking methane along with other sources of methane that could be mistaken for natural gas emissions.
If there were natural gas leaks of that magnitude across the natural gas industry, then methane levels in the atmosphere would be much higher that surveyed in the air sampling studies. Brandt and his team then took a look at all the excess methane being released into the atmosphere. For their calculations, they assumed all that methane was coming from the natural gas industry.
And switching from coal to natural gas for energy production does reduce the total greenhouse effect on a scale of years, the standard scientists use in calculations like these. But the climate benefits of such a switch are not as clear as the switch from coal to natural gas. Taking into account methane leaks from extraction all the way down the pipeline to the pump may actually make natural gas less climate friendly than diesel.
For example, burning natural gas results in less air pollution and less reliance on imported petroleum. Is it harmful to the environment, or the last great clean energy source? Perhaps we shouldn't ask whether natural gas is a good source of energy, but instead examine what makes a good energy source in the first place. So what is natural gas, anyway? Natural gas, like oil and coal, is a fossil fuel , formed deep below the surface of the earth. Scientists believe that natural gas, much like oil, formed millions of years ago when the remains of ancient plants and animals broke down under pressure and heat.
The decaying matter formed gas, which got trapped in porous rocks in areas that were later covered with harder rocks. Natural gas is primarily made of methane, the lightest hydrocarbon a compound of hydrogen and carbon. Natural gas has no color or odor. It's a good source of energy today; after all, there's plenty of it in the United States. If that wasn't enough, it can be produced and transported affordably.
Natural gas is often praised as a clean energy alternative. It burns more cleanly than other fossil fuels, emitting lower levels of harmful emissions such as carbon monoxide, carbon dioxide and nitrous oxides. It produces less greenhouse gases than other fossil fuels do. Many companies say they have been doing more to find and fix methane leaks. Advocates of natural gas argue that gas-fired power plants can provide continuous electricity, backing up wind and solar operations that run more intermittently.
Until batteries or other forms of energy storage become cheaper and more accessible, natural gas should serve as a complement to renewables, they say. Were they all to go ahead, the climate impact of the projects - including the effects of methane leaks - would exceed that of all coal-fired power plants under construction or in pre-construction planning worldwide, the report said. In theory, yes. Carbon can be captured and stored underground through a process known as carbon capture and storage CCS.
The oil and gas industry has stressed the potential benefits of CCS technology in tackling emissions. But the progress of that approach has been slow. Valerie Volcovici reported from Washington, D.
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