Floods caused by rising sea levels could cost as much as $14 trillion if we fail to keep global warming below 2°C.

Svetlana Jevrejeva from the National Oceanographic Centre in Southampton and her team predict that the annual cost of warming above 2°C could be equivalent to almost 3 per cent of global GDP by 2100. The costs are calculated based on damage to assets exposed to flooding and the costs of constructing and maintaining sea defences.

The team also looked at what missing the targets will do to global sea levels. It found that warming of 1.5°C by 2100 would see a median sea level rise of 0.52m. Breaching the 2°C the target – as is likely – would see this figure jump to 0.63m.

Who’s at risk?

Some nations will suffer more than most, particularly China, which has a long coastline and high coastal population, the team says.

Larger cities, regardless of wealth, are likely to be better-protected due to their existing infrastructure, whereas island nations and coastal communities in developing nations will suffer the brunt of the flooding. But these rises and floods will impact all coastlines, and every country will need to adapt, says Jevrejeva.

Jevrejeva says that the projections should spur governments into action. “Failing to achieve the global mean temperature targets of 1.5 ºC or 2 ºC will lead to greater damage and higher levels of coastal flood risk worldwide,” says Jevrejeva.

A recent report from the UK’s Climate Change Committee warned that the UK is not on course to meet its emissions targets in the 2020s and 2030s. Some models suggest we will have reached the 1.5°C target within ten years.