Research shows the response of the carbon cycle to climate change

Jun 20, 2012

Marine and freshwater environments have the potential to release more carbon dioxide (CO2) into the atmosphere in a warmer climate than their land counterparts, scientists at Queen Mary, University of London have found.

In the largest ever analysis of rates of , published online in the journal Nature today, scientists compared the temperature dependence of respiration between aquatic and land ecosystems.

Lead author, Dr Gabriel Yvon-Durocher from Queen Mary, University of London explained the context of the research: "In the carbon cycle, by plants absorbs () while respiration by animals returns CO2 to the atmosphere. Understanding how rates of respiration of entire ecosystems respond to changes in temperature will be crucial for forecasting future climate change as the planet warms in the coming decades."

In analysing annual rates of respiration across different ecosystems around the world, they found that aquatic ecosystems had a stronger response to than land ecosystems.

"Respiration has a higher 'activation energy' than photosynthesis, meaning that it increases more rapidly with increasing temperature. But over a longer time period, the carbon fixed by photosynthesis limits respiration on the land. However, many aquatic ecosystems receive additional carbon from the land, which washes into lakes, rivers, estuaries and the sea from rainfall. This extra carbon means that respiration in aquatic ecosystems is not limited by photosynthesis and can have a stronger response to temperature than ecosystems on the land," explained Dr Yvon-Durocher.

"These findings demonstrate that aquatic ecosystems have a greater potential to release CO2 to the atmosphere as the climate warms, over long periods of time."

The authors warn that there are many other factors that need to be considered when analysing the links between global warming and changes in the .

"Our research has highlighted the potential of aquatic ecosystems to contribute more CO2 to the atmosphere as global temperatures rise, but we can not definitively say that this will exacerbate the effects of climate change - it merely highlights a new mechanism that must be considered when making future predictions," Dr Yvon-Durocher said.

"Further research should be done to characterise the temperature sensitivities of the other key fluxes mediated by ecosystems that control the levels of greenhouse gases in the atmosphere to make more accurate predictions of future ."

Explore further: No-till agriculture may not bring hoped-for boost in global crop yields, study finds

More information: 'Reconciling the temperature dependence of respiration across time scales and ecosystem types' will be published online in the journal Nature on June 20, 2012.

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Howhot
3 / 5 (4) Jun 20, 2012
Interesting. We all have heard about the feed back loops that AGW has predicted and the article now that the aquatic ecosystem could have a greater CO2 release potential that was previously theorized. I've read somewhere, that when that as the Arctic ice melts, a sizable feedback release of CO2 (and methane) could result as the Arctic oceans absorb more solar energy by the change in surface albedo.
NotParker
not rated yet Jun 24, 2012
"These findings demonstrate that aquatic ecosystems have a greater potential to release CO2 to the atmosphere as the climate warms, over long periods of time."

Warming causes more CO2. As always. Not the other way around.
rubberman
not rated yet Jun 25, 2012
"These findings demonstrate that aquatic ecosystems have a greater potential to release CO2 to the atmosphere as the climate warms, over long periods of time."

Warming causes more CO2. As always. Not the other way around.


It's called a feedback....look it up.