Tropical changes may be key to more rainfall in UK

POLLUTION could be the issue responsible for making the tropics larger and this may in future increase rainfall in countries such as the UK.

Scientists have discovered soot particles from diesel engines and man-made ozone are likely to be the reason why the boundary of the northern tropics is being pushed further towards the North Pole.

While this will make sub-tropical desert regions even drier, it is also likely to drive rain further north, affecting the latitudes where the UK sits, according to the study by American scientists.

Professor Robert Allen, climatologist and assistant professor of Earth sciences at the University of California, Riverside, said: “If the tropics are moving poleward, then the subtropics will become even drier. If a poleward displacement of the mid-latitude storm-tracks also occurs, this will shift mid-latitude precipitation poleward, impacting regional agriculture, economy and society.”

In the past, it has already been shown that the tropics – the band around the equator bordered by the Tropic of Cancer in the north and the Tropic of Capricorn in the south – are widening by a combined 0.7 degrees each decade, meaning more people face drier, hotter conditions.

Research has previously found that the blame for the tropics widening in the southern hemisphere lies with ozone depletion high up in the atmosphere