Experts Deny Link Between Floods and Global Warming

floodThough the flooding in central England nearly a year ago were very severe, a scientific analysis on the event say that they cannot be linked to climate change.

The magnitude of last July’s floods prompted experts to say that they were due to climate change and an indication of similar summer-time flooding to come.

But, as per the report published by the Centre for Ecology and Hydrology in Wallingford, experts say that there is a trend for less flooding during summers and more rainfall during winters. Researchers of said institute analyzed flooding trends for the last forty years all across England, and arrived at this conclusion.

Terry Marsh of the Centre for Ecology and Hydrology said "the rainfall…was remarkable" and it fired speculations that the increasingly risky floods are due to global warming. "Due to the inherent variability of the UK climate, any extreme hydrological event cannot readily be linked directly to climate change" said Marsh.

The researchers also added that a historical view showed how truly phenomenal last year’s floods were. The affected areas include Gloucestershire, Oxfordshire, and towns along the rivers Severn and Avon.

Reviewing data that went back to 1766, from May to July last year, the average rainfall for England and Wales was 415 mm. This is the highest ever recorded. In a table showing the 15 wettest years only one other year occurred in the 20th century – 1924. In summer of that year (May to July), 308 mm of rainfall fell. That is 107 mm less than last year’s and is said to be the equivalent of seven weeks of average rainfall.

The detailed data on the river flows for the last 40 years only supports the theory that last years flooding was exceptional. Marsh and Jamie Hannaford show, in an analysis in the International Journal of Climatology, that river flows did increase but the said increases are mostly confined to the north and west. Hannaford said that "This trend is driven by an increase in, generally, winter high flows". Thus, last year’s summer floods happened in the wrong season and the wrong place which means that "The summer 2007 floods don’t really fit into these patterns."

The increase in winter flooding would fit prediction of some climate modelers for wetter winters and dryer summers. But, Hannaford said that it cannot be accurately determined whether the trends in the data are due to global warming. The British climate is too inconsistent from year to year to know for certain.

Hanford adds "We have only 40 years of data which generally is too short to determine whether or not these trends are caused by any underlying climatic mechanism." And even if the rainfall increases due to climate change, it might actually lowers the flood risks at some times of a year because there would be less snow melt in spring and the higher temperatures dry soiled earlier.

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