31 January 2002

Climate science: Flood warning

Two reports this week estimate the risk of extreme precipitation and flooding in a changing climate. Palmer and Räisänen use ensemble-based probabilistic predictions of the type developed in short- and medium-term weather forecasts to estimate the probability of excessive rainfall, and find a fivefold increase in risk over parts of the British Isles over the next 100 years and similar increases in probability for the Asian monsoon region—with serious implications for flood-prone areas in Bangladesh. Milly et al. show that the frequency of great floods—floods with discharges exceeding 100-year levels from river basins larger than 200,000 km²—increased substantially during the twentieth century, and that the trend is likely to continue.

Quantifying the risk of extreme seasonal precipitation events in a changing climate
T. N. PALMER & J. RÄISÄNEN
Nature 415, 512–514 (31 January 2002)
| First Paragraph | Full Text | PDF (201 K) |

Increasing risk of great floods in a changing climate
P. C. D. MILLY, R. T. WETHERALD, K. A. DUNNE & T. L. DELWORTH
Nature 415, 514–517 (31 January 2002)
| First Paragraph | Full Text | PDF (242 K) |

Climate science: The investment forecast
REINER SCHNUR
New studies predict that the risk of extreme rainfall over Europe and Asian monsoon regions is increasing, with more floods likely worldwide. Such long-range forecasting is pushing at the limit of current climate models.
Nature 415, 483–484 (31 January 2002)
| Full Text | PDF (317 K) |