Climate Change & Rivers
By Dr Arvind Kumar
According to a recent study, soaring temperatures and erratic rains brought on by a changing climate may radically alter water flows in the world’s major river basins, forcing people to give up farming in some areas. The study – part of a five-year research project on four continents, the first to take a close look at 10 river basins – is based on data from 17 climate models used by the Intergovernmental Panel on Climate Change (IPCC) to examine the potential effect of changing temperatures and rainfall patterns on the water flows in rivers from now until 2050. Mark Mulligan, a leading author of the study, has opined that climate models cannot predict how rainfall patterns will behave in future with a high degree of certainty: “What we do know is that we cannot be confident about hydrological stability. Some rivers could become wetter and then drier, or vice versa. The key message to countries is: ‘Become more adaptable’.”
The study expects that all African river basins will be water-stressed by increased rates of evapo-transpiration as temperatures rise, but is uncertain about how gains in rainfall may offset that impact. In Asia the seasonality of changes in rainfall and temperature – which affects how rivers behave in the wet or dry season – will be critical, especially in wet basins like the Mekong. Mulligan drew parallels with the uncertainty of the current financial crisis, pointing out that unprepared institutions and experts were responding in crisis mode. He said their findings on the impact of climate change on river basins indicate that the world faces an uncertain future regarding water, and the impact was unpredictable. A framework is needed to plan a strategy for the better management of water, and make countries and people more resilient.
