It is a cause for concern that new satellite research from the US space agency National Aeronautics and Space Administration (Nasa) shows that not only are global sea levels rising quickly, but they could rise even more drastically than previous reports estimated.
According to Nasa, seas around the world have risen an average of three inches (7.6cm) since 1992, and as much as nine inches (23cm) in certain places. According to Steve Nerem, head of Nasa’s Sea Level Change Team, it is pretty certain that planet Earth is locked into at least 3ft of sea level rise, and probably more. But it is not known now whether it will happen within a century or somewhat longer.
Sea levels are rising for three main reasons: The melting of ice sheets in Greenland and Antarctica, the melting of mountain glaciers, and the expansion of oceans as they absorb heat and become warmer. All three causes can be directly attributed to global warming.
The United Nations Intergovernmental Panel on Climate Change (IPCC) said in 2013 that global sea levels were likely to rise between one and three feet over the next century. But after studying 23 years of satellite information—the entire record of data available - Nasa warns that those estimates are probably too conservative.
“The data shows that sea level is rising faster than it was 50 years ago, and it’s very likely to get worse in the future,” Nerem said. The question now, Nasa says, is “how that range might shift upward.”
Citing satellite measurements, Nasa estimates that the Greenland ice sheet, covering 660,000 square miles - nearly the area of Alaska - shed an average of 303 gigatonnes of ice a year over the past decade
The Antarctic ice sheet, covering 5.4mn square miles - larger than the US and India combined - has lost an average of 118 gigatonnes a year. All that melted ice has to go somewhere.
Rapidly increasing sea levels could have drastic consequences for human populations, especially the hundreds of millions of people who live in coastal areas or on islands. Coastlines will erode, storm surges will rise, and some areas could become completely uninhabitable.
Writing in Gulf Times in May 2014, Abdullah al-Mamoon, a chartered professional engineer and a water and climate change expert, had warned that “Qatar and other countries in the Gulf region face serious challenges from climate change of mainly sea level and temperature rise. A metre rise in sea levels would directly affect 3.2% of the Gulf region’s population, with possible inundation of coastal towns, ports and increasing salinity of soil and fresh water reserves in the aquifers.
“Sea level and temperature rise will impact various infrastructures in Qatar; including buildings in coastal settlements, electricity distribution and transmission networks, water supply infrastructure, variety of onshore industries (petrochemical, power, desalination, waste water treatment and fertiliser plants etc.), port infrastructure and operations.”
Countries have to take notice of the Nasa research and redouble efforts to combat global warming, before it is too late.