Adaptation to 2 metres of sea-level rise should start today

“The IPCC AR6 makes clear that 2-m of sea-level rise will be exceeded sooner or later and this must be considered in all future coastal development” explained Robert Nicholls, Director of the Tyndall Centre and co-author of a latest paper about  multi-meter sea-level rise published in Environmental Research Letters.

Unlike other climate change impacts, sea levels will not stop rising as temperatures stabilise, continuing to rise for hundreds to thousands of years, even if average global warming was stabilised at 1.5C in line with the UN Paris Agreement. 

While the amount of global sea-level rise is unclear it will continue to rise and more than two metres of sea-level rise is inevitable. Estimates are two metres rise will be exceeded in the next century to 2,000 years in the future depending on future greenhouse gas emissions and ice-sheet melting. 

Coastal managers can act today to address this challenge. They can plan development in low-lying areas so that it can be easily adapted, especially for critical infrastructure, such as nuclear plants, ports and industry. Some coastal stakeholders are already acting in this way, such as concerning flooding on the Thames Estuary, UK. They can also create space for nature with immediate benefits for tourism and coastal biodiversity as explored by the coastal conservation agency in France. Stakeholders around the world can learn from and add to these examples as reflected in increasing attention to this issues. 

The authors set out three recommendations on how to avoid the worst impacts of sea-level rise. First, net zero greenhouse gases need to be reinforced and sustained to help postpone 2-m of sea-level rise further into the future, giving more time for coastal communities to plan adaptation. Second, monitoring for early warning signs on the collapse of ice-sheets must be strengthened and sustained. Third, coastal zone decision-makers and communities must commit to adaptation planning in their decisions, considering all options, including relocation where risk and hazard is too high.

There are multiple benefits in initiating adaptation today. First, some adaptation actions require decades to plan and implement. Acting now limits the risks of reactive or unmanaged responses. Second, it is an opportunity to develop resilient coastal areas that are projected to undergo rapid development in the next few decades. It can also help better manage ecosystems in coastal areas that are already degraded.

Robert explained “It may seem distant in the future, but much of the  infrastructure we have today and many that are planned are already in low-lying coastal areas. Sea-level rise is accelerating and adaptation will take time. We need to envision a future for coastal and estuarine areas for the next centuries”. 

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