Countless studies and climate models developed over the past several decades have revealed the dire state of our planet, with even worse things to come if we fail to take urgent and decisive action to curb global warming. Regardless of our efforts, however, some irreversible change is already underway – a new study, released on Monday in the Proceedings of the National Academy of Sciences indicates that Miami, New Orleans and many other iconic coastal cities in the US might soon be swallowed by rising sea levels no matter what we do.
Scientists have already established that if we do nothing to reduce our reliance of burning dead dinosaurs up to the year 2100, the planet will face sea level rise of 4.3 to 9.9 metres, said lead author Ben Strauss, Vice President for sea level and climate impacts at Climate Central.
“Just think of a pile of ice in a warm room. You know it is going to melt, but it is harder to say how quickly.”
The authors projected business-as-usual carbon emissions, in addition to the complication of the melting West Antarctic ice sheet, for at-risk land where more than 20 million people reside.
They also considered what might happen if the world were to make a big turnaround, reaching peak carbon emissions by 2020 – a radical scenario that would have to occur far earlier than the current aim of some world powers to peak by 2050.
An online tool that shows which US cities may face “lock-in dates beyond which the cumulative effects of carbon emissions likely commit them to long-term sea-level rise that could submerge land under more than half of the city’s population” has been released.
Based on the new model, Norfolk, Virginia faces a lock-in date of 2045 under a scenario of unabated carbon emissions, while cities like Miami and New Orleans have exceeded the limit already.
“In our analysis, a lot of cities have futures that depend on our carbon choices but some appear to be already lost. And it is hard to imagine how we could defend Miami in the long run,“ said Strauss.
The state of Florida has the most cities at risk from sea level rise, followed by California, Louisiana and New York.
That said, reducing carbon emissions to the levels seen in the 1950s by 2050 could still make a big difference. Under this scenario, a total of 14 cities with more than 100,000 residents could avoid locking in this century, including Jacksonville, Florida; Chesapeake, Norfolk; Virginia Beach in Virginia; and Sacramento and Stockton in California.
According to Michael Mann, a well-known author on climate change, the study provides a “better quantification of the detrimental impacts of the magnitude of sea level rise we may commit to in the decades ahead if we continue with business-as-usual policies of fossil fuel burning”.
A global version of the online tool is expected to roll out by next month.