New data predicted a four degree temperature change could cause a number of plants to stop balancing carbon dioxide in our environment; this could be a catastrophic turn of events for humans.
Climate change linked to greenhouse gas emissions could cause the carbon to "saturate" high-vegetation areas keeping plants from effectively absorbing CO2 and accelerating climate change, a University of Cambridge news release reported.
Recent climate models found looking at the length of time carbon resides in plant life during the global carbon cycle (residence time) is an excellent way to predict how plants will behave as the temperature warms.
The researchers believe the carbon's residence time will significantly decrease as the temperature rises. This would cause carbon to be re-released into the atmosphere at an accelerated rate, increasing the rate of climate change along with it.
"Extensive modelling" has found an increase of four degrees would cause "natural carbon 'sinks' of global vegetation become "saturated" and unable to sequester any more CO2 from the Earth's atmosphere," the news release reported.
Carbon sinks are systems that naturally remove CO2 from the atmosphere and store it; such as plant life.
The researchers believe the study shows the need for a "change in research priorities," putting more focus on carbon "residence times."
As CO2 levels increase plants will have accelerated growth; but drought and extreme temperature change will cancel out the benefits. A number of negative effects could occur such as "moisture stress," a phenomenon that occurs when a number of the world's plant cells don't have enough water.
Vegetation sinks could get so saturated in carbon that they "flat line" and are no longer able to absorb the climate change-fueling substance.
"Global vegetation contains large carbon reserves that are vulnerable to climate change, and so will determine future atmospheric CO2," Doctor Andrew Friend from the University's Department of Geography, said. The impacts of climate on vegetation will affect biodiversity and ecosystem status around the world."
The team used seven global vegetation models to reach their conclusion.
"We use data to work out the mathematics of how the plant grows - how it photosynthesises, takes-up carbon and nitrogen, competes with other plants, and is affected by soil nutrients and water - and we do this for different vegetation types," Friend said.
Friend hopes these findings will influence future policy decisions.
"The idea here is to understand at what point the increase in global temperature starts to have serious effects across all the sectors, so that policy makers can weigh up impacts of allowing emissions to go above a certain level, and what mitigation strategies are necessary," he said.
