Research shows that global sea level is accelerating

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Research shows that global sea level is accelerating

2018-08-30 00:25:35 292 ℃

Xinhua News Agency, Beijing, August 29 (Reporter Liu Shiping) The reporter learned from the Institute of Atmospheric Physics of the Chinese Academy of Sciences on the 29th that the World Climate Research Program's Global Sea Level Income and Expenditure Research Group released an evaluation report indicating that since 1993, the world The sea level has risen markedly, with an average annual upward trend of 3.1 mm, and this upward trend is accelerating.

The World Climate Research Program is an earlier program in global change research. Its purpose is to expand people's understanding of climate mechanisms, predict climate change, and monitor the impact of human activities on the climate.

This assessment report, co-authored by more than 90 scientists from around the world, including Chinese scientists, analyzes global sea level changes and their contributing factors since 1993. Since 1993, the main cause of global sea level rise has been the thermal expansion effect caused by ocean warming and the injection of fresh water from the land glaciers and ice sheets into the ocean.

Among them, the thermal expansion effect caused by ocean warming contributed 42%, the melting of terrestrial glaciers contributed 21%, and the melting of the Greenland ice sheet and the Antarctic ice sheet contributed 15% and 8%, respectively. In addition, the fresh water affected by precipitation, evaporation, runoff, etc., also affects global sea level changes, but its short-term fluctuations are strong and difficult to observe, and the contribution to sea level changes is highly uncertain.

Sea level change is a comprehensive indicator of climate change that is affected by changes in the oceans, atmosphere, and cryosphere. Cheng Lijing, an associate researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said that the data of the Institute of Atmospheric Physics of the Chinese Academy of Sciences, which participated in the preparation of this report, shows that the global oceans have continued to heat up in recent years. In the first half of 2018, the thermal content of the upper 2000 m ocean reached a new high. It has the highest record since modern observation. The continuous warming of the sea will further push the global sea level.

The 2018 China Blueprint for Climate Change published by the China Meteorological Administration shows that the comprehensive observations of the climate system and a number of key indicators indicate that the global warming trend continues. From 1980 to 2017, China's coastal sea level showed a volatility, with an average rate of increase of 3.3 mm/year, higher than the global average for the same period. In 2017, China's coastal sea level was 58 mm higher than the 1993-2011 average, the fourth highest since 1980.

Experts pointed out that sea level rise has important socio-economic impacts, which will increase disaster risks in coastal areas, such as destroying ecosystems, eroding land, and strengthening storm surges. Systematic monitoring, attribution analysis and estimation of sea level changes are the basis for addressing risks.