Extinction risk to plant biodiversity may occur at lower levels of atmospheric CO2 than previously considered
June 29, 2009(PhysOrg.com) -- Scientists have traced a sudden collapse in plant biodiversity in ancient Greenland, some 200 million years ago, to a relatively small rise in atmospheric carbon dioxide which caused a rise in the Earth’s temperature.
According to the findings published in the leading journal Science, the current estimated levels of atmospheric carbon dioxide which are thought to lead to sudden biodiversity loss may have to be revised downwards.
However, the scientists from University College Dublin, The Smithsonian Institute in Washington DC and Oxford University, have cautioned that their study findings may not have accounted for additional atmospheric gases such as sulphur dioxide which may have emerged from extensive volcanic emissions at the time to also play a role in driving the rise in the Earth’s temperature.
“Examining the 200 million year old fossil leaves from East Greenland, we discovered that the ancient biodiversity crash happened at atmospheric greenhouse gas levels of approximately 900 parts per million,” said Dr Jenny McElwain from the UCD School of Biology and Environmental Science at University College Dublin, Ireland, the lead researcher on the project.
“If we continue with the current intensive use of fossil fuel energy, some estimates calculate that carbon dioxide levels in the earth’s atmosphere will reach 900 parts per million by the year 2100. This is exactly the same levels at which our study identified the mass biodiversity collapse in ancient Greenland.” But according to Dr McElwain, this is a worst case scenario.
“Clearly, our study on ancient ecosystems shows that we must take heed of the early warning signs of deterioration within modern ecosystems, as we have seen from the past that very high levels of species extinctions - as high as 80% - can take place very suddenly although preceded by long intervals of ecological change,” she explains.
Using a new technique developed by Professor Peter Wagner at The Smithsonian Institute, the team of international scientists were able to detect very early signs at which plant diversity in ancient ecosystems were in a state of steady decline before they went extinct.
The new method reveals the early warning signs that an ecosystem is in trouble in terms of extinction risk. “The differences in species abundances for the first 20 meters of the cliffs from which the fossils were collected, are of the sort you expect given imperfect sampling of the same ecosystem,” said Professor Wagner. “But the final 10 meters show dramatic loses of diversity that far exceed what can be attributed to sampling error: the ecosystems were supporting fewer and fewer species.”
"Earth's deep time climate history reveals startling discoveries that shake the foundations of our knowledge and understanding of climate change in modern times," said H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which partially funded the research.
Provided by University College Dublin
Jun 18, 2009 |
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If things don't change they will stay just as they are!
There, I've made more sense than they have, can I have the money now, please?
And there is scientific evidence that increased CO2 does not increase plant growth, quite the opposite. Increased CO2 would also increase temperatures, increase precipitation, and increase Nitrogen content in soil. These things put together have been shown to decrease plant growth.
This particular article is nonsense.
Claiming you can learn anything meaningful about a link between CO2 and 200 million-year-old fossils is hard enough but the idea that CO2 at a mere 900 ppm harmed them is ludicrous. Crack open a botany text and see for yourself.
Pre-emptive policy is a relic of the cold war days, dusted off and exercised during the Iraq wars.
Do you want to look for weapons of mass climate change? I'd prefer to do the proper analysis before dooming millions to lives of poverty.
Americans are lucky, most of us won't hurt other than financially if there are missteps in the regulation of GHG's, however, not everyone on the planet lives in the food production heartland of the world.
Any regulation, regardless of the views of those involved, must be well thought out and performed appropriately so that both the environment and the health and well being of our fellow man can be maintained.
Lol. Too true. I gave your response a 5.
Translation: "I'm a moron too, high five!"
Godfather: Don't bother trying to defend yourself with "science" this place is a hang out for people with no real grasp of reality and have already decided what they want to believe. Its basically where like-minded dicks come to beat each other off and pretend their opinions actually matter to anyone other than themselves. You can find the same kind of folks talking about UFOs, crop circles, etc., all over the net. They bitch about how the 'main-stream' is always wrong and they are the ones who 'know the truth!'. Meanwhile, the real world ignores them and carries on with actually making a difference. Thank god they are they constrained to writing bullshit on little comment sections below the real articles, where nobody but their sad little followers come.
Imagine if these guys actually made a difference in the world?? We'd be fucked!!
Oh, sorry for interrupting guys, carry on as you were! Where were again...oh yeah "them scientists don't know shit, I knows stuff cos i got the internets! yuk yuk!"
I'm outta here!
Malarky! There have been several studies with CO2 and plants that have shown increases of plant mass and crop yield as high as ~39% by doubling CO2 levels of those at present.
Plants can continue to grow and photosynthesize in levels as high as 0.9% of the atmosphere before being unable to function properly. Today's levels are at between 0.03% and 0.04%.
By the way, plants grew to huge heights in prehistoric times due to higher levels of CO2! There was enough to go around, and then some, too! It was when the levels fell that plants began dying off.
Another thing that is of interest is that plants still carry the genes that allow them to process higher levels of CO2. In a couple studies I read these ancient genes switched on when levels of CO2 were increased.