According to the recent report from the Intergovernmental Panel on Climate Change submitted the UN. The Sea levels are rising faster than their prediction, which laid bare the severe risk to coastal cities and low-lying islands from climate change and the parlous state of the world’s oceans.
A gold standard of scientific research, outlined the threat to hundreds of millions of people from the acceleration in the rate at which sea levels are rising, caused by a combination of melting ice in polar regions such as Greenland and Antarctica and the expansion of the oceans as the water warms.
The researchers fear the extreme floods, which have historically occurred only once per century, were likely to happen at least once per year by 2050 in many regions, especially the tropics, even if global warming is limited to 1.5C. The findings come just days after the UN climate summit in New York, where the 16-year teenage activist Greta Thunberg told the assembled heads of state: “If you choose to fail us, we will never forgive you”. Despite pledges from world leaders to cut greenhouse gas emissions, the levels of carbon dioxide in the atmosphere continue to rise.
So what have they found and how bad is it?
In a nutshell, the waters are getting warmer, the world’s ice is melting rapidly, and these have implications for almost every living thing on the planet. “The blue planet is in serious danger right now, suffering many insults from many different directions and it’s our fault,” said Dr. Jean-Pierre Gattuso, a co-ordinating lead author of the report.
The scientists are “virtually certain” that the global ocean has now warmed without pause since 1970. The waters have soaked up more than 90% of the extra heat generated by humans over the past decades, and the rate at which it has taken up this heat has doubled since 1993.
The seas were once rising mainly due to thermal expansion – which refers to the way the volume of water expands when it is heated. The extra energy makes the water molecules move around more, causing them to take up more space. But the IPCC says rising water levels are now being driven principally by the melting of Greenland and Antarctica.
Thanks to warming, the loss of mass (which refers to the amount of ice that melts and is lost as liquid water) from the Antarctic ice sheet in the years between 2007 and 2016 tripled compared to the 10 years previously.
Greenland saw a doubling of mass loss over the same period. The report expects this to continue throughout the 21st Century and beyond.
For glaciers in areas like the tropical Andes, Central Europe and North Asia, the projections are that they will lose 80% of their ice by 2100 under a high carbon emissions scenario. This will have huge consequences for millions of people.