Scientists say that measurements provided by satellites and aircraft indicate that sea levels have risen over the past decade at the fastest rate in half a century. According to researchers, the cause of this phenomenon is the melting ice sheets and increasing sea temperatures. Experts believe that if this trend continues, it will lead to catastrophic consequences.
Throughout Earth’s history, glaciers have repeatedly expanded and contracted, and sea levels have risen and fallen with the warming and cooling of the climate. However, the current rise in sea levels will have a different impact compared to when the last Ice Age ended thousands of years ago.
Waleed Abdalati, an expert on Earth’s snow-covered areas who works for the National Aeronautics and Space Administration (NASA), states: “The difference today is that there are many people living in low-lying coastal areas who are highly vulnerable to disasters. It is estimated that about 100 million people will be affected if sea levels rise by just one meter. Therefore, this is certainly an important issue that requires long-term attention.”
So far, the rise in sea levels over the past decade has only been measured in a few millimeters, but it is enough to concern scientists, such as Steve Nerem from the University of Colorado in Boulder. He notes that U.S. satellites tasked with monitoring sea level heights have recorded a 50 percent increase in the rate of sea level rise since 1992 compared to measurements taken by tide gauges in previous decades. Nerem explains: “If we look at the data from tide gauges over the past 50 to 100 years, we see an average sea level rise of 1.8 millimeters per year. Now, over the last 12 years, thanks to data from NASA satellites, we have detected a change in the rate of sea level rise. We see a long-term trend here, and the average increase over the past 12 years is around 3 millimeters per year.”
Nerem mentions that data collected from ships show that about half of the sea level rise is due to the natural expansion of water as it warms, while the other half is due to water from melting ice. Eric Rignot, a NASA expert on Earth’s ice cover, notes that satellite data collected since the mid-1990s shows that the retreat of glaciers and ice sheets is occurring faster than previously thought. Rignot states: “A large portion of the water melting from ice sheets and flowing into the oceans today comes from mountain glaciers. These glaciers are located in areas such as Alaska, Patagonia, and the Himalayas. Glaciers in Patagonia and Alaska are retreating at rates 2 to 3 times faster than in the previous century. In Greenland, we are seeing the edges of ice sheets melting away. In Antarctica, we have observed rapid erosion of ice in the Antarctic Peninsula, which extends towards South America.”
Rignot points out that a warming atmosphere is a significant cause of this phenomenon.
For those who do not believe that an average rise of 3 millimeters per year is significant, Laury Miller, who collects such data at the National Oceanic and Atmospheric Administration (NOAA), explains that such a small increase can cause extensive damage over time. Miller states: “The issue for coastal areas is not just flooding. It’s not simply about rising water levels. There are also erosion effects, and these erosion impacts are broader than you might think in terms of vertical water level changes. With the current increase in sea levels, erosion over a century could cause coastlines to recede by 15 to 30 meters.”
At Pennsylvania State University, geographer Richard Alley mentions that if just 15 percent of the ice in Greenland melts, it would create enough new water in the oceans to inundate the entire southern part of Florida and many other coastal regions around the world. Alley states: “The world is currently warming, and ice sheets are changing as one would expect in a warmer world. Many of us have been surprised to see these ice sheets melting so quickly in certain areas. Right now, we really do not know how much of what is happening, so we do not feel alarmed. On the other hand, we also do not fully understand enough about this issue to feel reassured.”
Alley adds that more data needs to be collected over the coming years to provide more accurate forecasts regarding the impacts of rising sea levels.
Thu Huong (According to VOV News)
