A new study finds that, for each degree Celsius that global temperatures increase, sea levels could rise by 2.3 meters, and will remain high for centuries to come.
The study from the leading climate institute, Potsdam Institute for Climate Impact Research, was the first to pair data from climate history with computer simulations of contributing factors associated with long-term sea-level rise. This included ocean thermal expansion, glacier melting, and melting of the Greenland and Antarctic ice sheets.
Researchers contribute the melting ice to global warming. The International Panel on Climate Change (IPCC) says the burning of fossil fuels has released heat-trapping gases, which are nudging up temperatures..
Anders Levermann, lead researcher of the study, is confident the research has led to a robust benchmark estimate, having used a combination of physics and data.
Last century, sea levels rose by 17 cm, a rate which, according to the IPCC, has accelerated to more than 3 mm a year. Of the current rise, a third has been attributed to the Antarctica and Greenland ice sheets. Previous studies have predicted sea levels will increase by up to 2 meters by 2100.
Nearly 200 governments have agreed to limit global warming to 2°C above pre-industrial temperatures. By the end of 2015, a deal to curb emissions should be in place. Since the Industrial Revolution, global average surface temperatures have risen by 0.8°C. Within the next two decades, temperatures will likely increase another 0.4°C to 1.0°C, up from the previous two decades.
To narrow down uncertainties about the impact of melting ice on ocean levels, head of the Ice-2-Sea project, David Vaughan, has predicted that in this century sea levels will rise by 16.5 to 69 cm under a scenario of moderate global warming. The biggest impact this will have is the effect on storm numbers and intensity.
The results indicate that major adaptation along coastlines is necessary. It’s likely that some currently populated regions will not be protected in the long run
Still, a small number of scientists deny any sort of human influence on global warming, believing natural climate fluctuations are responsible. These so called climate skeptics find the current evidence unconvincing, and say changing temperature measurements are unreliable, contradictory and are not backed up by solid historic data.
They continue to question the accuracy of computer climate forecasts, pointing to historic, cyclical changes in global temperatures as evidence that these changes are natural. Others think the evidence indicates temperature rise has stopped, and that the effect of human activities shadows in comparison to the role of the sun.