Satellites recorded on Earth an accelerated increase in the most serious problem

13 February 2018, 16:15 | Science and Health 
фото с glavnoe.ua

The study, conducted on the basis of 25 years of satellite imagery, found that the level of the world's ocean rises not at a stable 3 mm per year, as was assumed earlier. The rate of ocean level rise is accelerated by approximately 0.08 mm / year. This means that by the year 2100 the rate of water rise will reach 10 mm / year or more.

"This acceleration, caused mainly by the melting glaciers of Greenland and Antarctica, has the potential to double the growth rate of the world's oceans by 2,100 compared to forecasts suggesting greater consistency in growth - over 60 cm instead of 30," says Steve Nerem, professor at the University of Colorado at Boulder. - And this is almost certainly a conservative estimate. Our extrapolation assumed that the level of the world ocean will continue to change in the future at the same rate as it was in the past 25 years. But, taking into account the major changes that we see in the ice sheets, this does not seem to be the case ".

If the ocean continues to rise at such a speed, its level will increase by 65 cm by 2100 - this is enough to cause serious problems to coastal cities, scientists at a number of universities and research centers, including the Goddard Space Flight Center (NASA) and the National Center for Atmospheric research. The results are published in the journal Proceedings of the National Academy of Sciences.

The growing concentration of greenhouse gases in the Earth's atmosphere raises the temperature of air and water, which has a dual effect on the world ocean level. First, warm water expands. This caused the growth of the ocean level by about 3.5 cm over the past 25 years. Secondly, melting ice falls into the ocean. These changes have been recorded with the help of satellites since 1992, however, it is difficult to measure the growth of the ocean level, even in the long term. Due to volcanic activity and similar natural phenomena, fluctuations in the level of the world's oceans occur, which can be influenced by changes in the phases of the Southern Oscillation (El Nino and La Nina). Therefore, scientists had to resort to several climatic models and gravity data obtained from the satellite GRACE.

The authors of the study consider the data obtained to be only the first step. For 25 years, enough data has been collected for the initial detection of changes, but for more thorough results it will be necessary to conduct additional satellite observations, HiTech writes with reference to Phys.. org.

Источник: glavnoe.ua