ENVIRONMENT: FLOODING IN THE UK
A
It began with a heat wave and drought throughout much of the United Kingdom in March of 2012, the third warmest March on record and the fifth driest. The rivers, aquifers and reservoirs were at their lowest levels, and water companies were prepared to introduce restrictions on water use, such as a ban on hosing yards. But just one month later, ground water levels were above average during a period when they should have been dropping. With a low pressure area lingering over the UK and causing a long spell of rain, the National Weather Service published a report, calling April an anomaly. The anomalous month became an anomalous year, and the series of storms that have been racking Great Britain and Ireland is now in its third year.
B
Destruction to land and property, including the collapse of the Great Western Canal, heavy coastal damage, and the flooding of the railway and main roads, has already cost Britain billions of dollars. Large parts of southern England are under water, and the Moorland village on Somerset Level cannot be traversed without a land boat or watercraft. In 2012, residents in Moorland vowed to fight back with sandbags, but almost all of them have since abandoned the land they swore never to leave. While the weather in the United Kingdom has been wretched in other years, the recent pattern can no longer be called an anomaly. Weather researchers say it is just the beginning, and residents can expect the wet and miserable weather to continue for a few more decades.
C
Taken separately, each of the low pressure systems that have visited the UK since April of 2012 was nothing out of the ordinary, but the rapid succession with which they came as well as their staying power have resulted in nearly non-stop rains that have saturated the ground. The lingering storms are ascribed to a confluence of physical events that began with higher than normal ocean temperatures in the tropical West Pacific and Indonesia. This gave rise to increased rainfall over the area, causing major changes in the Pacific jet stream. A jet stream is an air current that flows in the upper part of the troposphere. Usually, jet streams travel uniformly, evenly and with great speed unless influenced by the landmasses and the Coriolis effect. The former can cause a jet stream to meander rather than move rapidly, mainly because of friction and temperature differences, whereas the latter can accentuate the effect. With higher temperatures and increased rainfall in the West Pacific, the Pacific jet stream began to meander, lingering over the United Kingdom and causing wet and windy weather.
D
The North Atlantic jet stream was affected as well by the warmer Arctic temperatures, part of the warming that is said to be taking place globally. Temperature differentials between the Arctic and the temperate zone fuel this jet stream. When the differential is high, the jet stream speeds through the atmosphere like a river rushing downhill. However, when the differential is low, the jet stream tarries, like a river flowing slowly across a flat bed. This causes storms to virtually stand still, lingering for weeks on end. As such, the number of flood warnings in the UK have increased from 9 in 2012 to 130 in 2013, with some 100 warnings still in effect as of January, 2014.
E
The great irony of the flooding is that it commenced soon after the government made budget cuts for flood defence, likely because it didn’t seem important at the time. The flood defence projects that were ongoing were either put on hold or cancelled. But as the months passed and the flooding became more catastrophic, the government was forced to commit funds to flood control and urge insurance companies to honor existing policies. These have paid out a total of about 14 million pounds in emergency payments; the projected cost to by the time all payments are made is expected to exceed one billion pounds.
F
Another issue that has gained attention with government is whether global warming is the cause of the protracted monsoon rains and flooding in the UK. Supporters of global warming as cause urge government to earmark funds for programmes to prevent future flooding. They note that the “prolonged spell of rain … was very unusual,” and that human activity has long been implicated in climate change. But others are more conservative, pointing to a need to study climate models to determine whether global warming even exists. Solid evidence, they argue, is needed before large investments can be made to control floods and defend coastal areas. However, whether or not the extreme weather was caused by global warming, the problem of flooding does exist and must be dealt with in the present before the losses mount and damage to land becomes permanent.
G