Surface temperatures may not be rising as quickly as they were, but that's just one small part of a much bigger and more troubling picture

CLIMATE sceptics are finding it ever harder to persuade the public that the climate isn’t changing. So now some are turning to a more last-ditch line of attack: even if climate change is happening, it’s not worth worrying about.

They have been emboldened by scientists’ acknowledgment that temperatures on the planet’s surface have risen less sharply than expected in recent years. The scientists say that’s down to natural variability; the doubters say it is a sign that climate change amounts to little more than ignorable, or even beneficial, “lukewarming”.

This has been presented as a credible position on television, in newspaper headlines and magazine articles – and it is echoed in public policy. The UK prime minister, keen to reduce winter fuel bills, is rethinking levies and policies aimed at making the country’s energy use more sustainable. Perhaps he thinks the climate can wait.

But it is misguided to focus only on the temperature of the thin layer of air that we live in. That is just one of many important indicators. In particular, the oceans are warming too: recent research suggests that in the last 60 years the Pacific’s depths have warmed 15 times as fast as at any time in the previous 10,000 years.


It is misguided to focus only on the temperature of the thin layer of air that we live in

And the oceans may have been soaking up heat faster still over the past few years. That may in turn explain why the atmosphere isn’t warming as fast as it was (see “Climate slowdown: The world won’t stop warming“). Warmer oceans have consequences. Consider typhoon Haiyan, thought to be the fourth-strongest storm in history. Such storms usually stir up cooler waters that limit their strength; Haiyan, by contrast, kept gaining energy from exceptionally warm waters extending far below the surface. More such storms will follow as the oceans heat up.

Warming oceans also pump more moisture into the air, which can lead to unprecedented rainfall – as Colorado discovered earlier this year. And water expands as it warms: around a third of the continuing rise in sea levels is due to water expansion. That sea level rise is expected to accelerate, putting many of the world’s greatest cities at risk.

Of course, the nature of climate science makes measurement tricky; and its predictions are fraught with uncertainties. But there are also certainties. We know global warming continues – the sea levels alone show that. We know human emissions of greenhouse gases are to blame. We know warming will accelerate as long as emissions keep rising. And we know from history that societies struggle to adapt when the climate changes. Filipinos thought they knew what to expect from a tropical cyclone. They weren’t expecting Haiyan.

You might be able to ignore surface temperatures for the moment, if you live in one of the few places yet to be seriously adversely affected – so not places like Sydney or California. Those are getting fewer, however; and temperatures will at some point start climbing sharply again.

And there’s still sea level rise, extreme weather, disrupted jet streams, receding polar ice, biodiversity collapse, forest fires, ocean acidification and more to be concerned about – to say nothing of the huge challenges of “greening” our societies.

Time to stop worrying about warming? On the contrary.

This article appeared in print under the headline “Causes for climate concern”