The Climate Issue newsletter: The surprising effects of Europe’s heatwaves

Oliver Morton, our planetary affairs editor, on how an unusually hot, dry summer is testing the continent’s infrastructure

When I was travelling up to London on Thursday morning from my home about 60km to the south of the capital, I was a little irritated that the train was late. When I heard it was due to speed restrictions on the line, I was more understanding. Hot weather makes metal rails expand, and that brings risks that can be lessened by rolling along them at more cautious speeds.

People have an understandable but sometimes unhelpful tendency to attribute unusual events to unusual circumstances. (Unsplash)

My return home that evening was a little more fraught, and considerably less direct. An earlier train down from London had come off the rails outside Lewes, the town where I live. Three carriages had toppled over. A lot of people were knocked around and a couple seriously injured.

No one can explain the derailment with any certainty. But the possibility that the rails buckled in the heat is very much in the mix. So is the possibility that the drought now afflicting the south of England and all of Wales has led the clay of the embankment the railway is built on to dry out and subside.

People have an understandable but sometimes unhelpful tendency to attribute unusual events to unusual circumstances. The accident investigators may well find different explanations. But the fact that today, with temperatures still very high, there has been another derailment (this time in Essex) adds to suspicions. Whatever the outcome, next time I type out something along the lines of “higher temperatures will stretch the capacity of existing infrastructure, sometimes to breaking point”—an idea I have found myself expressing so many times in the past that it has developed a slight feel of boilerplate—I will do so with a sense of the close-to-home that I haven’t had before.

It is not just railways. All sorts of infrastructure has been found wanting in Europe’s very hot and dry summer. In the paper this week we report that in Kaub, a town in Rhineland-Palatinate, the Rhine is currently just 12cm deep. The Danube is not doing much better. The cruise ships that ply both rivers are staying away. Barges are carrying reduced loads. If water levels get much lower, the upper Rhine and the lower Rhine will become two separate rivers, as far as transport is concerned.

A lack of water in the rivers is not just a problem for boats. In some places dams are reducing their electrical output as a result of their reservoir’s reduced liquid input. Djerdap 1, Serbia’s biggest hydropower plant, is running at about a third of its normal output. But the problems are most acute for nuclear plants, which rely on river water for cooling.

Hot summers present two problems for such plants. One is that environmental regulations often require the water downstream of the plant to stay below a given temperature for the benefit of the ecosystem. When the riverwater is hot, the amount of extra heat the plant can dump into it is limited. Such concerns regularly reduce the production of plants in France.

The other is that sometimes the rivers simply do not have enough water for the plant’s needs. Romania has shut down two reactors at Cernavoda because the Danube fell too low to provide sufficient cooling water. There is now a state of emergency in the country’s energy sector. Neighbouring Moldova, which relies on Romanian power, faces severe restrictions. Upstream in Hungary, the reactors at Paks, which provide a large proportion of the country’s electricity, have been running at a fraction of their usual capacity. And the summer is not over yet.

Romania sought to keep the second reactor at Cernavoda running by using explosives to blast away riverbed obstructions and sinking rock-filled barges to change the flow. It has not proved enough. Hungary is planning to build an emergency weir that will raise water levels at Paks; if it needs to act sooner, it too has barges ready for scuttling.

There are longer-term measures to take. Previous droughts have prompted Germany to shift away from relying on river traffic. Its companies are also using barges with shallower drafts. Électricité de France, a state-owned utility company, has announced investments to improve resilience in the face of drought at both its nuclear plants and its hydropower plants. (Drought is not the only climate-related problem it faces. On August 10th some of the jellyfish thriving in the uncommonly hot sea found their way into the cooling system of its Gravelines plant, near Dunkirk, shutting down three reactors.)

Britain’s railway operator, Network Rail, which already has contingencies for excessive heat, will no doubt be reviewing them whatever the cause of the accidents in Sussex and Essex. Planning for summers hotter than any previously experienced is increasingly the norm among infrastructure operators of all sorts. But they are stymied by what they have inherited from more clement times—times from which the world is getting ever more distant. And for as long as that is the case, higher temperatures will stretch the capacity of existing infrastructure, sometimes to breaking point.

Have you been affected by the heatwaves in Europe? Write to us at climateissue@economist.com.