More oxygen -- colder climate

September 10, 2009

Everybody talks about CO2 and other greenhouse gases as causes of global warming and the large climate changes we are currently experiencing. But what about the atmospheric and oceanic oxygen content? Which role does oxygen content play in global warming?

This question has become extremely relevant now that Professor Robert Frei from the Department of Geography and Geology at the University of Copenhagen, in collaboration with colleagues from Uruguay, England and the University of Southern Denmark, has established that there is a historical correlation between oxygen and temperature fluctuations towards global cooling.

The team of researchers reached their conclusions via analyses of iron-rich stones, so called banded iron formations, from different locations around the globe and covering a time span of more than 3,000 million years. Their discovery was made possible by a new analytical method which the research team developed. This method is based on analysis of chrome isotopes - different chemical variants of the element chrome. It turned out that the chrome isotopes in the iron rich stones reflect the oxygen content of the atmosphere. The method is a unique tool, which makes it possible to examine historical changes in the atmospheric oxygen content and thereby possible climate changes.

"But we can simply conclude that high oxygen content in seawater enables a lot of life in the oceans "consuming" the CO2, and which subsequently leads to a cooling of the earth's surface. Throughout history our climate has been dependent on balance between CO2 and atmospheric oxygen. The more CO2 and other greenhouse gases, the warmer the climate has been. But we still don't know much about the process which drives the earth from a period with a warmer climate towards an "ice age" with colder temperatures - other than that oxygen content plays an important role. It would therefore be interesting to consider atmospheric and oceanic oxygen contents much more in research aiming at understanding and tackling the causes of the current climate change," says Professor Robert Frei.

The results Professor Frei and his international research team have obtained indicate that there have been two periods in the earth's 4.5 billion year history where a significant change in the atmospheric and oceanic oxygen content has occurred. The first large increase took place in between 2.45 billion years and 2.2 billion years ago. The second "boost" occurred for only 800 to 542 million years ago and lead to an oxidisation of the deep oceans and thereby the possibility for life to exist at those depths.

"To understand the future, we have to understand the past. The two large increases in the oxygen content show, at the very least, that the temperature decreased. We hope that these results can contribute to our understanding of the complexity of change. I don't believe that humans have a lot of influence on the major process of oxygen formation on a large scale or on the inevitable ice ages or variations in temperature that the Earth's history is full of. But that doesn't mean that we cannot do anything to slow down the current trend. For example by increased forestry and other initiatives that help to increase atmospheric and oceanic oxygen levels," explains Professor Robert Frei, who, along with his research team, has worked on the project for three years so far.

Source: University of Copenhagen

4.1 /5 (10 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

Sean_W
Sep 10, 2009

Rank: 1 / 5 (1)
The oxygen enables more life to consume the CO2? Wouldn't it make more sence if more life was creating more oxygen AS it consumed CO2? That's usually how photosynthetic organisms work right?
Sean_W
Sep 10, 2009

Rank: not rated yet
Sorry for the typo - it should still make sense.
no1enter
Sep 10, 2009

Rank: 3 / 5 (2)
Hold on 3,000 million years? What the....!?!?! you mean 3 billion?

3,000 x 1,000,000 = 3,000,000,000 or 3 billion
nkalanaga
Sep 10, 2009

Rank: 5 / 5 (2)
The problem with "billion" is that it means 10^9 in the US and 10^12 in Britain. 3000 million means the same in both countries.
defunctdiety
Sep 10, 2009

Rank: 5 / 5 (1)
The problem with "billion" is that it means ... 10^12 in Britain. 3000 million means the same in both countries.

And I learned something today.

You crazy limeys :)
nkalanaga
Sep 10, 2009

Rank: 5 / 5 (1)
Sean: You're probably right. As the amount of life increased, it produced more oxygen, and CO2 levels fell. But plants can also grow faster in higher oxygen levels, at least partly because they don't have to use as much of their food to survive at night. Thus, as the plants produce more O2, they also grow faster, which allows them to produce even more. It's a feedback loop, and can continue until oxygen levels are high enough that fires become a major threat. At least one paper I read said that cellulose is spontaneously combustible at normal pressure with O2 levels above 40%. At that point, any ignition source would cause massive wild fires, lowering O2 and raising CO2 levels. Then the process would start over.
Rank 4.1 /5 (10 votes)
Related Stories
Relevant PhysicsForums posts
  • Do some geologists actually act a lot like Randy Marsh?
    created23 hours ago
  • Discrepancy between oxygen and carbon-dioxide levels
    createdFeb 09, 2012
  • where gems are found in the world
    createdFeb 09, 2012
  • Wind Waves in Reservoir ~ Wind run-up and Wind set-up
    createdFeb 08, 2012
  • Balance of oxygen in the atmosphere
    createdFeb 01, 2012
  • The case for a methanol-based economy
    createdJan 30, 2012
  • More from Physics Forums - Earth

More news stories

Latin America mining boom clashes with conservation

Latin America is experiencing a mining boom as prices rise fuelled by a hike in global demand, but the region is also being hit by a wave of violent protests, strikes and rallies by environmentalists.

Space & Earth / Environment

created 1 hour ago | popularity not rated yet | comments 0

Europe stakes billion-dollar bet on new rocket

A pencil-slim rocket is scheduled to lift into space from South America on Monday, carrying a billion-dollar bet that Europe can grab a juicy slice of the market to place satellites in low orbit.

Space & Earth / Space Exploration

created 21 hours ago | popularity 4 / 5 (3) | comments 0

Political leaders play key role in how worried Americans are by climate change: study

More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of climate change, new research finds.

Space & Earth / Environment

created Feb 06, 2012 | popularity 5 / 5 (6) | comments 72

NASA budget will axe Mars deal with Europe: scientists

US President Barack Obama's budget proposal to be submitted next week for 2013 will cut NASA's budget by 20 percent and eliminate a major partnership with Europe on Mars exploration, scientists said Thursday.

Space & Earth / Space Exploration

created Feb 10, 2012 | popularity 5 / 5 (3) | comments 55

Humans may have helped the decline of African rainforests 3000 years ago

(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...

Space & Earth / Environment

created Feb 10, 2012 | popularity 4.1 / 5 (14) | comments 20 | with audio podcast report


Google might launch Drive for cloud storage soon

(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...

Love a click away in Indonesia's Twitter Republic

He was a geeky kid from Yogyakarta, she a glamorous city girl in Jakarta. In a country with one of the world's most vibrant social networking scenes they fell in love on Twitter.

Walney offshore wind farm is world's biggest (for now)

(PhysOrg.com) -- The Walney wind farm on the Irish Sea--characterized by high tides, waves and windy weather--officially opened this week. The farm is treated in the press as a very big deal as the Walney ...

GPS court ruling leaves US phone tracking unclear

A US Supreme Court decision requiring a warrant to place a GPS device on the car of a criminal suspect leaves unresolved the bigger issue of police tracking using mobile phones, legal experts say.

Europeans protest controversial Internet pact

Tens of thousands of people marched in protests in more than a dozen European cities Saturday against a controversial anti-online piracy pact that critics say could curtail Internet freedom.

Study finds that anti-diabetic medication can prevent the long-term effects of maternal obesity

In a study to be presented today at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in Dallas, Texas, researchers will report findings that show that short therapy with the anti-diabetic medication ...