Coastal cities in danger
How does climate change affect coastal flooding?
By 2050, COASTAL FLOODS that used to hit once a century will strike many cities every year, according to the IPCC, the gold standard on climate science. This is because climate change has made sea levels rise.
Higher seas make storms worse in two ways.
- First, tropical cyclones create storm surges. This means fast winds and low atmospheric pressure raise the level of water hitting the coast. This increases the frequency and intensity of flooding by raising the platform from which storm surges strike.
- Then there’s the rain. After a storm, rainfall further inland that has built up tries to escape into the oceans. But this can overwhelm the capacity of drainage channels in the ground and burst riverbanks. As that travels downstream to the oceans, it can worsen flooding in coastal cities.