Science 327, 454–458 (2009)

Credit: NASA

The number of strong storms in the western Atlantic could double by the end of the century, despite a drop in the overall number of storms, finds new research. Previous studies have hinted at an increase in hurricane intensity, but scientists have now used a modelling approach capable of capturing storms of category-3 or higher intensity, enabling them to simulate twenty-first-century storms realistically.

Morris Bender of the US National Oceanic and Atmospheric Administration and colleagues applied a two-step 'downscaling' technique to increase the resolution of climate models. Using the ensemble-mean of 18 global climate models and 4 regional models, they assessed the climatic response to a 'business as usual' emissions pathway. They then employed a hurricane model to simulate storm development in response to the projected warming. In the simulations, the number of category-4 and category-5 storms in the Atlantic Ocean rose 81 per cent by 2100, while the number of storms with winds greater than 65 metres per second increased by 250 per cent. The largest jump in intense storm activity occurred in the western Atlantic Ocean.

The researchers caution that the increasing numbers of the strongest storms could drastically raise the cost of storm damage.