Geologists Chris von der Borch and Dave Mrofka collect sediment samples in South Australia. These rocks hold clues to help explain why climate changed 635 million years ago.
Click on image for full size
Courtesy of Martin Kennedy, UCR
Scientists Search for the Cause of Ancient Global Warming
News story originally written on May 28, 2008
Earth’s climate is warming quickly now. We know that this has to do with more greenhouse gases in the atmosphere and other global changes. But there is a lot we don’t yet know about how warming will change our planet. How could we know? We’ve never been through this before, have we?
In fact, even through we humans have never seen fast global warming, our planet has. And our planet keeps records of what happened. The oldest records that the Earth keeps are in its rocks.
Geologist Martin Kennedy looked through some very old sedimentary rocks – 635 million years old. He and other scientists collected hundreds of bit of rock from South Australia. Each rock had information in it about what climate was like long ago.
By studying the rocks the scientists found evidence that fast global warming had turned Earth from a cold place into a very warm place 635 million years ago.
Earth had been covered by a thick ice sheet for millions of years before the warming started. Then a little warming caused the ice sheets to collapse. This released a large amount of the greenhouse gas methane into the air. The methane caused very fast global warming.
Today, methane is in frozen ground in the Arctic and beneath the oceans. Researchers believe that it will stay where it is unless global warming releases it into the air. If warming lets the methane loose, Earth could warm tens of degrees.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, as well as books
on science education!
You might also be interested in:
Only a tiny amount of the gases in Earth’s atmosphere are greenhouse gases. But they have a huge effect on climate. There are several different types of greenhouse gases, but they all have something in...more
This page is not yet developed at the elementary level. Please check back for updates or click on the "Intermediate" button above for information....more
Methane is a kind of gas. There is a small amount of methane in the air you breathe. A methane molecule has carbon and hydrogen atoms in it. Methane is a greenhouse gas. That means it helps make Earth...more
This page is not yet developed at the elementary level. Please check back soon for updates or click on the "Intermediate" button above....more
In the Arctic, you will find the Arctic Ocean surrounded by the continents of Europe, Asia, and North America. You will find the geographic North Pole and the magnetic North Pole there; both are in the...more
Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. Adam Kent, a geologist at Oregon State University, says this...more
The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core. The mantle is made up of many different reservoirs that have different chemical compositions. Scientists...more