Vagaries of weather could delay UN climate treaty

Waiting for extreme weather events to prompt climate action could lead to “decades” of policy delay, say scientists 

Pic: Katy Silberger/Flickr

Pic: Katy Silberger/Flickr

By Sophie Yeo

Extreme weather events can prompt politicians into delivering strong policies on climate change – but relying on them too heavily could delay action for decades, say scientists.

Wild weather can provide a window of opportunity to introduce climate policy, as the immediate impacts of events such as heat waves and floods raise support for efforts to reduce emissions among local populations.

But depending on extremely variable local weather patterns to provide a reason for tough climate action is a risky strategy, according to scientists Katharine Ricke and Ken Caldeira from the Carnegie Institute for Science.

“When support for doing something about climate change is based on personal observations of local weather, policymaking may end up being dictated by the roulette wheel of natural climate variability,” says Ricke.

This could delay meaningful action on climate change by “decades”, they say, as the weather is highly variable, whereas policy efforts must be sustained over the coming decades. As such, waiting to feel the impacts directly is a bad strategy when implementing climate policy.

The findings are published in Nature Climate Change.

Recent examples where extreme weather events and policy have overlapped include President Obama’s US$ 1billion climate resilience fund to help drought-stricken California and Filipino climate commissioner Yeb Sano’s emotional plea for progress at last year’s UN climate conference in the aftermath of Typhoon Haiyan.

Natural variability

According to a recent study by the UN’s climate science panel, the onset of man-made climate change is likely to mean the weather will become less stable, triggering extreme events such as heat waves and flooding across the globe.

But even when the weather appears as normal, the world is continuing to warm, thanks to the large amounts of greenhouse gases that humans have pumped into the atmosphere. This means extreme weather events are likely to become more frequent and severe in years to come.

Veteran climate scientist Caldeira says that politicians need to be careful to draw the distinction between using extreme events as leverage to draw political support for climate action, and as a direct catalyst for new policy.  

“Local weather is anecdotal information, but climate change is sound science,” he says. “Good politics can be based on a good anecdote, but good policy needs to be based on sound science.”

While the paper’s modelling shows that within 50 years every country will experience the kind of extreme weather that can be a policy trigger, natural variability means that it could be years before some people, particularly in large countries like China and the US, personally experience such extremes.

The scientists modelled the amount of time it is likely to take for the world’s six top emitters to support an international treaty on climate change [see below].graph1

Japan emerged as the quickest, while Russia and the US lingered in fifth and sixth place respectively.

Climate change is likely to have some positive economic effects in Russia initially, as the thawing of Arctic sea ice allows the Northern Sea Route to be developed.


“The spread of the results for each emitter here is due entirely to natural climate variability,” said Ricke.

“From this large spread in the results, we can see that natural climate variability, superimposed on a global warming trend, has the potential to affect the timescale for reaching national – and thus international – political consensus on climate change mitigation.”

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