Rising carbon dioxide levels in the atmosphere can have a mixed impact. It can lead to more floods during the summer because of the rise in river levels but can also make plants more immune to droughts — a recent study by the United Kingdom met office has found.
The study reveals a significant link between CO2 levels and its impact on plants' ability to absorb water thereby causing more water to flow into the rivers. “Higher the level of CO2 in the atmosphere lesser the ability of the plants to soak water from the soil," said Richard Betts, a computer modeller at the UK Met Office in Hadley.
The plants’ ability to soak water from the soil with high levels of water content prevents flooding during heavy rains. Now the risk of flooding in high rainfall areas would increase significantly — meaning more floods during India’s monsoons.
The scientists predict there will be disadvantages as well as benefits. Droughts may be less severe than anticipated in some regions, but the risk of flooding could increase significantly. "It's a double-edged sword," Betts said. "Plants will lose less water. On the other hand, if the land is saturated one might expect that intense rainfall is likely to cause more flooding."
The paper was published in the last edition of the environment magazine Nature.
Betts stressed the importance of treating individual gases such as CO2 and methane differently, while predicting a 6 per cent rise in the level of water flowing in rivers, and a rise in rainfall in the warmer world.