The broadcaster and campaigner looks at the impact of global warming on our oceans and whales, and invites your thoughts on the subject.
The effects of global warming
There’s no denying it – human-induced climate change is an existential threat to all life on Earth. A recent landmark report by the UN Intergovernmental Panel on Climate Change tells us that we have until about 2030 to get our act together, if there is to be any hope of keeping it to manageable proportions. If we don’t, we’ll pass a tipping point and the consequences will be nothing less than catastrophic.
The evidence is all around us – shrinking glaciers, disappearing sea-ice, worsening floods, more and more hurricanes with escalating power, and longer and more intense heat waves and droughts.
For wildlife, global warming is placing additional pressures on ecosystems that are already stressed by many other human-induced threats. At worst, warming temperatures will lead to population or species extinctions. At best, they are forcing animals to shift their breeding seasons or move to higher latitudes or elevations (causing further complications, as they enter regions occupied by other species).
It may not be cataclysmic – at least, not in the scheme of things – but there are significant changes afoot in the world of whales. And it’s because oceans, which serve as natural sponges, have absorbed more than 90 per cent of the excess heat and about 30 per cent of the carbon dioxide generated by human consumption of fossil fuels. In 2017, ocean temperatures were by far the hottest ever recorded. The Arctic Ocean, in particular, is warming more rapidly than any other region on the planet
– according to NASA, it is likely to become completely ice-free in summer before the middle of the century.
Consequently, some whales are going where they have never been before. It was headline news recently when a pair of sperm whales was spotted off the northern tip of Baffin Island, in Canada’s high Arctic, far from their normal range. But that is just the tip of the iceberg, so to speak.
Killer whales are taking advantage of longer, ice-free summers by extending their range further and further north into the Arctic – with some potentially serious consequences. For a start, they are hunting narwhal. These tusked whales are not used to being threatened by anything other than people and occasional polar bears, and are being driven from some of their richest feeding grounds by this new cetacean peril.
Perhaps more importantly, the loss of Arctic sea-ice is opening up the Northwest and Northeast Passages to all sorts of whales. Until quite recently, ice prevented them from swimming between the North Pacific and North Atlantic – but now they can. In the past decade, for example, grey whales – which were hunted to extinction in the Atlantic – have been spotted again for the first time since the early 18th century (one off the coast of Israel and another off Namibia). As ice barriers are reduced, it is quite possible that we will start to see a steady trickle of them arriving in the Atlantic from the Pacific and, ultimately, they could recolonise. There is evidence that other species are also moving to the ocean next door or meeting in the middle. How they will fare – or what impact they might have on their new homes – no one knows.
An editorial in The Guardian summed up our complacent attitude to climate change perfectly: ‘Even apocalyptic science fiction deals with bands of survivors who have, by definition, survived. And we always imagine ourselves as among the survivors.’ Unless we live up to the most ambitious goals of the Paris Agreement – which, given current evidence, seems shockingly unlikely – ocean-hopping whales will be the least of our worries.
MARK CARWARDINE is a frustrated and frank conservationist.
WHAT DO YOU THINK? If you want to support Mark in his views or shoot him down in flames, email wildlifelet[email protected]mediate.co.uk
If we don’t act, we will pass a tipping point, with catastrophic consequences.
Loss of sea-ice leads to species, such as grey whales, moving beyond their usual range.