Global climate change is, unfortunately, the bleeding wound of our planet. Global warming, which affects living things of various sizes, can even cause old bridges to collapse due to extreme climatic conditions.
Extreme weather conditions caused by climate change threaten collapse of old bridges. The recent collapse of a bridge in the Grinton area of North Yorkshire has raised many questions about how prepared we are for such risks. The bridge, which was on the World Cycling Championship route in September, collapsed in just four hours after a month of rains, causing a small flood of surrounding houses.
The collapsing bridge in Grinton is not the first bridge to be destroyed by climate change. In 2015, storms first named Eva and then Frank caused severe damage to the 18th-century Tadcaster bridge in North Yorkshire and the nearby medieval Eamont Bridge in Cumbria. Floods in 2009 destroyed 29 bridges in the Cumbria region alone.
With climate change making such heavy rains more widespread in the future, it is a question of whether such bridge collapses will occur more in the future.
Indeed, if bridges are being affected and destroyed by global climate change, which bridges are at greater risk? We know that bridges can collapse for various reasons. Some just collapse because they're old. Some are destroyed by the wrong material or environmental processes such as floods, erosion and earthquakes. Even bridges can collapse due to ships hitting them.
Europe's first major roads and bridges were built by the Romans. These infrastructure investments developed greatly during the industrial revolution, and most of them later became the II. It was rebuilt after World War II but has since increased the pressure on various factors, bridges and other critical structures. For example, when many bridges were first built, the traffic mostly consisted of pedestrians and animals. This was not a serious weight for the bridges, but after decades of passing over the bridges, things changed and became more severe.
Engineers around the world think that countless bridges can reach the end of their expected lifespan (between 50 and 100 years), but we don't know which bridges are most at risk. This is because there is no national database or method to identify structures at risk.
Since different bridge types are sensitive to different failure mechanisms, we need to evaluate each bridge on its own axis. In Newcastle, for example, the seven bridges along the Tyne River connect the city to the town of Gateshead. These bridges vary in function (pedestrian, road and rail), material (steel to concrete) and age (17 to 150 years) parameters. Therefore, the risk and type of failure for each bridge is very different.
The flood is considered a major threat in the UK's National Emergency Risk Registry. Although Met Office's latest climate forecasts show a decline in average rainfall in winter and rainfall in summer, precipitation naturally varies widely. Floods are caused by particularly heavy rainfall. Therefore, it is necessary to look at not only the average of precipitation but also how it changes.
Warmer air can hold more moisture and therefore can cause extreme rainfall, such as in Grinton. High resolution climate models and observational studies also show excessive rainfall intensity. All these studies mean that bridges will be more likely to collapse due to flooding in the future. In order to mitigate future disasters, we need to review our infrastructures, including assessments on change in use, aging and climate change.