Carbon dioxide tends to get the most hate when talking about greenhouse gas emissions. But, there’s another gas that’s even worse. Methane. The Environmental Protection Agency (EPA) says pound for pound, the “comparative impact” of methane on climate change is over 20 times greater than carbon dioxide over a 100-year period.
Scientists were surprised to discover 570 vents, also called seeps, leaking methane gas from the ocean floor just off the U.S. East Coast. The findings were published on August 24 in the journal Nature Geoscience. The seeps were discovered on the ocean floor stretching from North Carolina to Massachusetts, and “could be adding as much as 90 tonnes of the planet-warming gas to the atmosphere or overlying waters each year.”
“Effects of these (methane) plumes on climate and ocean chemistry are not yet clear, but could extend well beyond the plumes themselves,” says the journal Nature in a press release.
The nearly 600 seeps were discovered using sonar scans of the sea floor between 2011 and 2013. Researchers were shocked by the number of seeps. Previous reports put the number of seeps at just a handful in the region.
Adam Skarke, a geologist at Mississippi State University says the bubbles coming from the vents usually dissolve into the sea before they reach the surface.
The discovery leads to more questions. Previous estimates put the number of methane seeps off the east coast at just a handful. Now they discovered 570. How many could there be? The study suggests “tens of thousands of seeps could be discoverable.”
Plus, the discovery throws a wrench in previous estimates of greenhouse gas emissions. And, just because the discovery is a new one doesn’t mean it’s new. Skarke told NBC News, “The fact that it is there in the quantities that it is and it is exposed suggests that indeed the processes at these locations have been going on, in a very general sense, on the order of at least 1,000 years.”
While all of this sounds terrible, the methane gas coming from the ocean floor usually dissolves back into the water before reaching the surface and entering the air. Good news for the near term, like the next 100 years or so. But, still a problem long-term.
Methane emissions from burning fossil fuels and natural causes such as tropical wetlands and melting permafrost will have a more immediate impact.
What’s all this mean for us? No The Day After Tomorrow scenario hopefully. Dennis Quaid might want to prep his snow shoes for future generations, though.