Flood risk from climate change underestimated

For the thousands of people whose homes were damaged in the widespread flooding in the UK this summer, it may seem like a joke. But scientists have announced that climate change may carry an even higher risk of flooding than was first thought.

A new model produced by the Met Office’s Hadley Centre has shown that current estimates of increases in water levels fall short, due to a failure to acknowledge the effect of carbon dioxide on vegetation. As part of the process of photosynthesis through which they make their energy, plants absorb water from the ground through their roots and exhale it into the air from their leaves as water vapour. However, higher levels of CO₂ inhibit their ability to do this, which will result in less water being transferred from the ground to the air. Soil is likely to become waterlogged and flooding exacerbated. Richard Betts, the scientist behind the research, commented that “current impact assessments will need to be reworked.” The results, published in journal Nature today, predict that climate change and its effect on plants will cause river flow to increase by 13% over the next 300 years unless CO₂ emissions are reduced.

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