Plants can combat rising CO2
9 May 2012 by Evoluted New Media
Terrestrial ecosystems may be able to absorb more anthropogenic carbon dioxide emissions than previously thought suggests new research.
The results improve the ability to look into the planet’s future and predict the magnitude of climate change before it happens; say the team from Imperial College London and the University of York.
Scientists grew plants in sealed experimental cabinets and provided them with soil, light, water and a controlled atmosphere that mimicked one of the Intergovernmental Panel on Climate Change (IPCC) optimistic scenarios of man-made greenhouse emissions.
Over several months, they measured how well the plants absorbed CO2 under changing environmental conditions. The plants absorbed a large proportion of the additional CO2, preventing the temperature from increasing more than 2.3°C.
“Experiments of this nature are key to accurately predicting the future levels of carbon dioxide and global temperatures,” said Dr Alex Miclu from Imperial. “We’re really improving our understanding of how plants react to global environmental changes, but a discrepancy exists between our results, those from ‘open’ unsealed experiments, and data from the best computer simulations.”
“Right now, the best way to improve these simulations is through more experimental work to understand the way that carbon cycles between soil, vegetation and the atmosphere.”
This research – published in Nature Climate Change – has addressed a key question in environmental science about whether an increase in global temperatures will cause an increase or decrease in the ability of ecosystems to absorb CO2 from the atmosphere. Some scientists predict it will cause the release of greenhouse gases from oceans and soils, leading to runaway climate change. Others suggest an explosive growth of plants and algae to mop up extra CO2.
“Our results suggest the role plants have in cleaning up excess CO2 from the atmosphere may be pretty good – at least at lower levels of anthropogenic CO2 emissions,” said Dr Martin Lukac.
“We do have to be cautious in scaling up the results from our sealed-cabinet experiments to the whole world, and probably would not expect to see such a strong effect in real ecosystems due to additional limiting factors such as nutrient and water availability.”
Scientists hope this type of experiments with real plants will complement computer simulations of the carbon cycle and they are now looking to repeat the experiment with the inclusion of an analogy of the world’s oceans.
“Our experimental findings made total sense but suggested that the capacity of the Earth to buffer against rising CO2 may be greater than the computational models imply,” said Professor Phil Ineson. “We still have the same major concerns about climate change, but the Earth system may have some tricks up her sleeve.”
