A satellite image of Sentinel-2 from May 20 shows the Dutch province of Zeeland, including the port of Rotterdam, the largest seaport in Europe on the upper right. Much of the region is below sea level and is based on a complicated system of dams, canals and dams for survival.
Credit: European Space Agency
Credit: European Space Agency
Climate change is making the oceans rise faster than scientists’ most pessimistic forecasts, resulting in earlier flood risks for coastal economies already struggling to adapt.
Revised estimates released Tuesday in Ocean science have an impact on two-fifths of the Earth’s population living near the coast. Billions of dollars worth of insured property could face even greater danger from floods, storms and tidal waves. Research suggests that countries will need to reduce their greenhouse gas emissions even more than expected to keep sea levels under control.
Explore dynamic updates to Earth’s key data points
“It means our carbon budget is even more depleted,” said Aslak Grinsted, a geophysicist at the University of Copenhagen who co-authored the research. The savings must reduce another 200 billion metric tons of carbon – the equivalent of about five years of global emissions – to stay within the thresholds set by previous forecasts, he said.
The warmer it is, the faster the sea level rises. The sensitivity models of the future seem to be incompatible with historical data.
Credit: Aslak Grinsted
The researchers relied on the models of the United Nations intergovernmental panel on climate change, many of which have taken into account only the last 150 years, incorporating data dating back several centuries. New observations show that about half a meter of sea rise by the end of the century is now expected, with only a temperature rise of 0.5 degrees Celsius. The oceans could rise more than 1 meter to 2 degrees Celsius, a trajectory that will be easily passed under the current climate policies.
“The models on which we currently base our forecasts for sea level rise are not sensitive enough,” Grinsted said. “To be clear, they don’t strike a chord when we compare them to the rate of sea level rise we see when we compare future scenarios with observations that go back in time.”
The findings follow last month’s warning that rising temperatures have melted 28 billion metric tons of ice – the equivalent of a 100-meter sheet of ice covering the entire Kingdom – making climate scenarios at worst likely. The new methodology for tracking sea level change could help insurance companies, real estate developers and city planners build tidal defense systems.
“The scenarios we are seeing now regarding sea level rise are too conservative – the sea seems, using our method, to grow more than is thought using the current method,” Grinsted said, adding that his team at the Niels Bohr Institute is in connection with the IPCC on the incorporation of its results in the sixth year Evaluation report.