Sea level rise is not a new phenomenon. For most of the 20th century, the global average sea level has risen – about 0.05 inches (1.4 millimeters) per year, according to the United Nations. Intergovernmental Panel on Climate Change. The global average sea level is the average of all seas Earth. But in the last two decades, the rate has more than doubled. From 2005 to 2015, sea levels rose by 0.1 inches (3.6 mm) per year.
But is this increase globally consistent?
No, no. “Sea level rise is not the same all over the world,” said Kathy Magnes, senior primary research scientist at the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia. He heads the Climate Extreme and Forecasting Committee of the CSIRO Center for Climate Science.
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Many places are rising while the global average is rising, but sea levels are falling in a few places, said Jackie Asterman, assistant professor of earth and environmental sciences at Columbia University’s Lamont-Doherty Earth Laboratory in New York. “There is no place to escape sea level change,” Asterman told LiveScience.
What causes sea levels to change? Climate change, Often. Rising temperatures will heat the air and water. As the water warms, it expands. Hot air and water also melt ice. “In Antarctica“Warming oceans play a major role in the formation of glaciers.” As glaciers melt, more water flows into the oceans, adding more to the oceans.
But where is that extra water going? It does not spread equally around the world, McKinsey said. Globally, there are two main factors – thermal expansion and the gravitational pull of ice. With Thermal expansion, Ocean currents redistribute heat, which moves around cold and hot water. “If there is more heat in some areas and less heat in others,” the warmer ocean areas will expand further, while cooler places will have less expansion, McKinsey said. He added that atmospheric winds could lower and raise the oceans. Also, as the planet warms, the shapes of that air change, Live Science previously announced.
When huge icebergs melt, they simply do not add water to the ocean. The mass attracts the mass. Antarctic and Greenland Glaciers are so large that their masses exert a gravitational pull on the ocean around them, Asterman said. Thus the sea level in those areas rises slightly. But as the ice melts, so do their masses. As the mass decreases, the force of gravity also pulls the water upwards. As a result, sea levels are falling near melting glaciers, for example in Greenland, but rising on the opposite side of the world, in this case the southern hemisphere, he added. “This pattern of sea level change in the world known as the sea level fingerprint is different to that particular iceberg,” Asterman said, explaining how each of the melting Greenland and Antarctic ice sheets has their fingerprint shapes.
Local effects such as groundwater pumping, fossil fuel extraction, and sedimentation are also exacerbating sea level rise, McKinns said. In some areas, especially in cities built on deltas such as Tokyo and New Orleans, land falls as sea levels rise. “Some of these big mega-deltas are actually sinking at a much faster rate than sea level rise,” McKinsey said. “It’s a double whammy, where land is declining and sea levels are rising.”
Natural climate cycles also contribute to sea level rise. ” El Nino and La Nina All the water accumulates on one side causing a vision-like effect [Pacific Ocean] At one point the basin, then at another level the basin will accumulate on the other side, ”McKinsey said.
Rising sea levels around the world can lead to catastrophic storms and frequent catastrophic floods or floods that cause general erosion, for example road closures. Storm water drainage systems are relied upon Gravity It must function properly between the inland and the ocean, so that if sea levels rise, water will not flow in the right direction through drainage system pipes, especially during storms. “If we continue to have storms, they will raise water levels above already high sea levels,” Asterman said. “This is a very short-term issue related to sea level rise.”
First published in Live Science.