Unprecedented heat cannot be ignored

July 29, 2018
 

 

 

As a prolonged heatwave envelopes much of the northern hemisphere, causing death and destruction through wildfires and heatstroke, climate experts are speaking out more forcefully about the link between extreme weather and global warming. Until recently, scientific caution prompted them to preface any pronouncement with a declaration that no individual event — flood, storm, drought or heatwave — could be attributed to man-made climate change rather than natural variability in the weather. The public often misinterpreted this as fundamental uncertainty about climate change itself.  

 

Now the evidence is strong enough for scientists to state clearly that global warming is directly making episodes such as this summer’s heatwaves more severe — and that things will become much worse in the decades ahead as fossil fuels pump more carbon dioxide into the atmosphere. 

 

There are two interlinked ways in which warming causes trouble. One is simply that the 1C average temperature rise since the industrial revolution exacerbates heatwaves and also rainstorms by putting extra energy and moisture into the atmosphere. More complex and troubling is the way it affects the whole atmospheric circulation — this summer, for example, weakening the jet stream and pushing it far further north than usual, letting a persistent area of high pressure settle over Europe. By the 2040s heatwaves like this year’s are likely to be routine summer events. 

 

As residual scientific doubts over global warning evaporate, the need for action by policymakers, businesses and private individuals becomes more urgent. Their response must combine “adaptation” to make society more resilient to the inevitable future impact of climate change with “mitigation” measures that cut carbon emissions. Forest fires stoke climate change debate. 

 

The adaptation process is only just beginning and needs to accelerate. Almost every aspect of modern life is vulnerable to increasing meteorological disturbances and extremes, from housing and health to emergency services and the transport infrastructure.  

 

One of the most important issues is how and where we build homes. As this week’s Greek tragedy illustrated, coastlines are particularly vulnerable to climate-related disasters. Local authorities must prevent illegal construction and restrict new building permits in vulnerable zones. Everywhere needs a safe evacuation route, should disaster strike. 

 

Whatever their location, new buildings should only be permitted if they have built-in climate resilience. In temperate regions that means meeting tight energy conservation standards to minimise seasonal heating requirements — yes we can still expect very cold snaps in the wilder winters induced by climate change — as well as inbuilt passive cooling which is essential in tropical regions. (One irony is that increasing demand for active cooling through air conditioning exacerbates global warming.) 

 

In the political world, action to implement the 2016 Paris Agreement must continue urgently in the regrettable absence of the US — or at least of its federal government. Several US cities and states, particularly California where heat-induced fires are currently causing devastation, remain committed to a strong carbon-cutting agenda. 

 

Meanwhile, in the short term, forecasters expect the heat to return for August to areas of north-west Europe that saw a sudden break in the weather this weekend. For many, this will be the hottest summer on record — and there is no denying that man-made climate change is to blame.