Methane
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Scientists in the U.K. have figured out how the Earth
recovered from a sudden episode of global warming during the
time of the dinosaurs. This could help us understand how to
survive the upcoming climate change.
Global warming caused the erosion of rocks to increase by
400%, leaching calcium and magnesium into the ocean. This
erosion could have been caused by an increase in rainfall, as
well as higher ocean levels. These chemicals combined with
the carbon dioxide that had been absorbed by the ocean,
causing a chemical reaction that led to falling levels of
greenhouse gases worldwide. Over a period of about 150,000
years, the Earth returned to normal.
Calcium combining with CO2 would have created calcium
carbonate, which does not increase global warming.
Researcher Anthony Cohen says, "This intense rock-
weathering effectively put a brake on global warming through
chemical reactions that consumed the atmosphere's extra
carbon dioxide."
But how did the world heat up in the first place? (Since
dinosaurs didn't drive SUVs). About 180 million years ago,
temperatures on Earth rapidly shot up, probably due to the
sudden release of huge amounts of methane from the ocean
floor. Methane is a greenhouse gas which quickly changes to
CO2, which stays in the atmosphere for a long period of time,
absorbing sunlight and heating up the Earth.
But where did the methane come from? Besides the vast
amounts that are frozen deep in the ocean floor, it may have
also come from the vast peat bogs in 200,000 miles of
Siberia. Climatologist Laurence Smith says, "The bottom line is
Siberian peat lands may be a bigger player in climate change
than we knew before."
And what triggers the methane release? Scientists at the
University of Wyoming say the ocean methane is released
when water temperatures rise. The methane in the ocean is
in a highly pressurized form and heat causes faults in the
ocean floor where it's stored to break apart, releasing the
gas. Matthew Horbach says, "It's like a cork in a champagne
bottle. If you shake up the champagne and build up enough
pressure, the champagne bubbles can pop the cork."
Smith says, "[This research] emphasizes a point that has
been emerging over the past few years; the idea that the
climate system is highly unpredictable and full of thresholds
that can trigger greenhouse gas sources and sinks to
abruptly switch on and off. The more of them we can
identify, the more accurately we can model and anticipate
changes in the future."
Cohen says, "What we have learned from these rocks is how
the Earth can, over a long time, combat global warming.
What we need to discover now is why and at what point it
goes into combat mode, and precisely how long the conflict
takes to resolve."
Global warming has now become a hot topic. But only
Dreamland fans know where it all started.
To learn more,
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k here and
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