Hurricane risk to northeast USA coast increasing say researchers
- Published: Thursday, 24 November 2016 09:21
The Northeastern coast of the USA could be struck by more frequent and more powerful hurricanes in the future due to shifting weather patterns, according to new research.
Hurricanes have gradually moved northwards from the western Caribbean towards northern North America over the past few hundred years, the study led by Durham University, UK, found. The researchers suggest that this change in hurricane track was caused by the expansion of atmospheric circulation belts driven by increasing carbon dioxide emissions. New York and other major cities along the Northeast coast of the USA could come under increased threat from these severe storms and need to be better prepared for their potential impact, say the researchers.
The findings have been published in the journal ‘Scientific Reports’.
Researchers reconstructed hurricane rainfall for the western Caribbean dating back 450 years by analysing the chemical composition of a stalagmite collected from a cave in southern Belize, Central America. They found that the average number of hurricanes at the Belize site decreased over time. When the hurricane history of Belize was compared with documentary hurricane records from places such as Bermuda and Florida, this information showed that Atlantic (Cape Verde) hurricanes were moving to the north rather than decreasing in total numbers.
Although natural warming over the centuries has had some impact on shifting hurricane tracks, the researchers found a marked decrease in hurricane activity in the western Caribbean coinciding with the late 19th Century industrial boom associated with increasing carbon dioxide and sulphate aerosol emissions to the atmosphere. The researchers said that initial regional cooling of the Northern Hemisphere due to increased industrial aerosol emissions should have pushed the hurricane tracks southward since industrialization. But they added that rising amounts of atmospheric carbon dioxide had overridden this effect by expanding the Hadley cell - a pattern of circulating air in the Earth's tropical belt - pushing hurricane tracks further north, away from the western Caribbean towards the Northeastern USA.
This suggests that from the late 19th Century, manmade emissions have become the main driver behind shifting hurricane tracks by altering the position of global weather systems, the researchers said.
If future trends in carbon dioxide and industrial aerosol emissions continue as expected, hurricanes could shift even further northward, exacerbating the risk to the Northeast coast of the USA.The research was funded by the European Research Council; the National Science Foundation; the Alphawood Foundation; the Schweizer National Fund, Sinergia; and the Inter-American Institute for Global Change Research.