Researchers have revealed through a study that only half a degree of more global warming could inundate coastal areas that are currently home to more than five million people thereby rendering them homeless.
The study, conducted by researchers at Princeton University and colleagues at Rutgers and Tufts Universities, the independent scientific organization Climate Central, and ICF International, concluded that by 2150, the seemingly small difference between an increase of 1.5 and 2.0 C would mean the permanent inundation of lands currently home to about 5 million people, including 60,000 who live on small island nations. The findings are published in the journal Environmental Research Letters.
While many believe that Paris Agreement is the key to the global warming and climate change issue, authors of the study point out that even under the best-case climate policy being considered today, many places will still have to deal with rising seas and more frequent coastal floods.
The researchers concluded that increase in temperatures will make extreme sea level events much more common. For their research, the team used long-term hourly tide gauge records and extreme value theory to estimate present and future return periods of extreme sea-level events through the 22nd century.
Under the 1.5 C scenario, the frequency of extreme sea level events is still expected to increase. For example, by the end of the 21st century, New York City is expected to experience one Hurricane Sandy-like flood event every five years.
Extreme sea levels can arise from high tides or storm surge or a combination of surge and tide (sometimes called the storm tide). When driven by hurricanes or other large storms, extreme sea levels flood coastal areas, threatening life and property. Rising mean sea levels are already magnifying the frequency and severity of extreme sea levels, and experts predict that by the end of the century, coastal flooding may be among the costliest impacts of climate change in some regions.
Future extreme events will be exacerbated by the rising global sea level, which in turn depends on the trajectory of global mean surface temperature. Even if global temperatures are stabilized, sea levels are expected to continue to rise for centuries, due to the fact that carbon dioxide stays in the atmosphere for a long time and the ice sheets are slow to respond to warming.
Overall, the researchers predicted that by the end of the century, a 1.5 C temperature increase could drive the global mean sea level up by roughly 1.6 feet (48 cm) while a 2.0 C increase will raise oceans by about 1.8 feet (56 cm) and a 2.5 C increase will raise sea level by an estimated 1.9 feet (58 cm).