Climate crisis | Infrastructure is hot

Summer heat waves have damaged infrastructure around the world. And this is only the beginning, warn the experts.

Philippe Robitaille-Grou
special cooperation

July 2022. Mercury rises above 40°C in the UK. A first in the country. The train tracks, designed for average British summer temperatures, take 9km to expand on the 30,000km network. Whole lines are closed. At Luton Airport, London, flights are suspended due to heat-induced runway warps. In the same town, Hammersmith Bridge is wrapped in foil to prevent it from cracking.

On a global scale, similar recent phenomena have highlighted the vulnerability of infrastructures in the face of high temperatures: ruptured water pipes in Texas, power cuts in Europe, the collapse of the roof of a museum in China, etc.

“Most infrastructure was designed based on past climate, without realizing how much it would change,” says Jo Sias, professor of civil and environmental engineering at the University of New Hampshire.

In the northern hemisphere, heat waves affecting several regions simultaneously are already seven times more numerous than 40 years ago, according to a study published in January in the scientific journal of the American Meteorological Society. These waves are also increasingly intense and cover increasingly large areas, according to the study.

Result: “We are heading towards a scenario where our capacity to respond to infrastructure failures will be exceeded,” worries Mikhail Chester, director of the Métis Center for Infrastructure and Renewable Engineering at the State University of the State of Arizona.

Mitigate risks

“It is necessary to reduce greenhouse gases, but also to adapt the infrastructures,” says Julien Bourque, research associate at the Climate Institute of Canada (CCI).

In the UK, train tracks have been painted white to prevent them from absorbing too much heat and deforming further. They are thus 5 to 10 degrees cooler, assesses Network Rail, owner of most of the British rail network.

In Canada, road asphalt is generally designed to withstand temperatures between 20°C and 30°C, according to the Intact Center on Climate Adaptation at the University of Waterloo. This asphalt is made up of rocks, sand and bitumen. “This mixture is very sensitive,” says Jo Sias. At too high temperatures, the surface softens. The problem is that the wheels of the vehicles can then leave permanent marks.

Certain types of bitumen provide better resistance to high temperatures. However, they are more expensive.

Roads and other public infrastructure are quite a headache for Canada. They are 60% managed by the municipalities, which “clearly do not have the necessary funding, not only to prepare these infrastructures for the future, but even to keep them in good condition at present”, deplores Julien Bourque.

The future bill

Another source of concern for the ICC: electrical networks. On hot days, power lines sag and their carrying capacity decreases. However, at the same time, the networks are facing an increased demand for air conditioning. This exacerbated pressure is likely to cause power outages. “And with our carbon neutrality objectives by 2050, we will need even more electricity and infrastructure,” warns Julien Bourque.

In his report titled Submerged: The Costs of Climate Change on Infrastructure in Canada, the CCI describes the long-term benefits of investing in resilient infrastructure. Replacing power grid components to adapt to anticipated heat and rain could reduce damage costs by 80% by 2100.

In the case of roads, up to 98% of the costs attributable to climate change could be saved by the end of the century by modifying materials and design, according to the report.

Prepare for the worst

“You have to solidify and strengthen as much as possible,” insists Mikhail Chester of Arizona State University. But we also have to accept that we will reach a limit. We will not be able to make all infrastructure resilient enough to deal with the massive uncertainties that climate change represents. The researcher wishes to put forward the method safe to failthat is to say the idea of ​​designing facilities ready to yield in a controlled manner to the weather.

Such an approach has been adopted in the Netherlands, with the “Room for the River” project. Near some rivers at risk of overflowing, the Dutch decided not to erect buildings and dykes. On nearby land, farmers were allowed to plant and warned that they would lose their crops every five to ten years, due to flooding. They were compensated in case of loss, which cost significantly less than the construction and maintenance of dikes.

“In the case of heat waves, one can think of electrical microgrids which, during power outages, would provide electricity for critical needs,” suggests Mikhail Chester. These would allow, for example, the air conditioning of community centers for the most vulnerable.

In Quebec, a first microgrid consisting of solar panels and storage batteries was inaugurated in 2021 in Lac-Mégantic. But like everywhere in the world, there is still a lot to do, says Julien Bourque. “We must ensure that governments consider adaptation and resilience in all aspects of decision-making in terms of funding and regulation,” he concludes. Otherwise, we will only build more risks. »