Climate change and potential impacts in the English Channel
The World Climate Change Conference 2015 at Le Bourget, Paris, formally opened yesterday with almost 150 world leaders, including David Cameron and Barack Obama, and 40,000 delegates hoping to reach a new agreement on global climate change.
Dr Phil Buckley, Senior Lecturer in Ecology and member of the Ecology Research Group at Canterbury Christ Church University brings the discussion closer to home giving his insight on how climate change may impact the English Channel:
A 2009 report by the Met office showed that surface temperatures in UK waters had increased by 0.7⁰C in the past three decades. This may not sound like much, but just think about how much more time it takes to heat up a full kettle compared to half a kettle, then scale it up to the billions of litres of surface seawater we have and you get some idea of how much extra heat energy has gone into our coastal waters in the last 30 years. There are also signs that sea temperature increase is accelerating.
In the long term, if sea temperature continues to rise, we could see the further loss of cold water species, such as cod, which will become increasingly rare in UK waters. Analysis carried out in 2014 showed that cod populations around the British Isles shifted northward over the course of the last century. This northward movement of cod populations was linked strongly to increases in sea temperature. At the same time, certain species of both invertebrates and fish from areas such as the Mediterranean could start to colonise the channel.
There are some special circumstances that apply to the UK, which might buck this trend. Higher global temperatures increase the melting of the northern ice cap, and all that freshwater could disrupt the Gulf Stream, the warm water current that contributes to our mild climate. This current has in fact slowed in recent years, and further slowing might lead to us getting colder waters.
One, admittedly unlikely scenario, is that a stalled Gulf Stream leads to sea temperatures routinely below 10⁰C, in which case we could get exotic cold water specialists such as harp seals, or even the enormous red king crab in our waters. The red king crab which is native to the Pacific, is currently making its way down the Norwegian coast towards us, which is possibly good news if you like crab meat, but not such a great thing for native invertebrates and sea bottom communities that lie in this predators’ path.