Rising temperatures due to climate change are a threat to railway infrastructure, according to a study by Beijing Normal University.
With an emphasis on China’s rail system, the researchers think just half a degree Celsius less warming would save economic losses of about $ 630 million (£ 452 billion) per year.
The rain-induced disaster risk of the railway infrastructure increased with increasing days of extreme rainfall in the decades from 1981-2016.
According to Liu Kai, the paper’s lead author, global warming would be limited to the Paris Agreement target of 1.5 ° C instead of 2.0 ° C, disaster risk of China’s railway infrastructure for extreme rainfall.
“A flood disaster could inundate the track [and] lead to defects in the subsurface and track structure,” she said. “Based on our statistics, a total of 975 historical disasters caused by rainfall from railways were reported from 1981 to 2016.
“Rain-induced debris flow was the largest contributor, about 42 percent; followed by the rain-induced flooding, which is about 26 percent; rain-induced landslides, about 18 percent, and rain-induced composite hazards, about 14 percent.
“The team used a“ random forest ”machine learning model to calculate disaster susceptibility and quantify the relationship between susceptibility and precipitation change.
” We found a remarkable increase in disaster susceptibility of rail lines along the Yangtze River valley, center of China with the greatest population density, “Liu said.” Disaster susceptibility has increased by 30 percent over the period 1999-2016 from 1981-1998.
” The level of the reference period (1981-1998) is expected to increase from 1.1 percent to 4.5 percent in 2050 and to 12 percent in 2090.
With a global average temperature increase of 1.5 ° C, direct damage and repair costs are expected to increase to an average of $ 1.47 billion per year.
With 2 ° C of warming, the damage doubles and the loss grows to $ 2.10 billion.
China’s railway system is still undergoing significant expansion and the total mileage of the railway lines is expected to be around 200,000 km in 2035, compared to around 140,000 km in 2020.
“The design of newly planned high-speed rail lines should take into account the effects of climate change. How to reduce the disaster susceptibility of the world’s most densely populated rail network must be planned to mitigate the negative impact, ” said Liu.
Last year, Britain’s Network Rail’s budget was cut by £ 1 billion in Chancellor’s Spending Review, despite recent government pledges to invest heavily in infrastructure.