Sea level rise: don't worry too much, long-term changes are still difficult to predict.

Sea level rise has always been one of the "ultimate disasters" under some theories.

According to the IPCC report, the sea ice area in the Arctic has been at the lowest level since 1850 in the past decade. Since 1980s, the frequency of ocean heat waves has doubled. It is conservatively estimated that since 2006, human activities have affected the generation of most ocean heat waves. Alpine and polar glaciers will continue to melt in decades or hundreds of years, and the carbon loss caused by the melting of frozen soil is irreversible on the Millennium scale. Due to the uncertainty of the ice sheet melting process, the average global sea level rise may exceed the expectation under the maximum emission scenario-2100 2m, 2 150 5m. Even in the most powerful emission reduction scenario, the sea level will continue to rise in the next hundreds or thousands of years.

Then, with the intensification of global warming in recent years, what is the speed of sea level rise?

The Blue Book of Climate Change in China published by the Climate Change Center of China Meteorological Bureau in 20 18 shows that the annual average surface temperature in China has shown a significant upward trend since the 20th century, with the last 20 years being the warmest period since the beginning of the 20th century. From 1980 to 20 17, the sea level along the coast of China fluctuated and rose, with an average rising speed of 3.3mm/year.

If this speed is maintained, it will take 606 years and the sea level will rise by 2 meters. 2 100 rises by 2 meters, which means that global warming is exploding and accelerating exponentially, which should be an extreme expectation.

At present, the atmospheric environment of the earth is still a complex subject. For example, volcanic eruptions will emit a lot of greenhouse gases and carbon dioxide, but the dust rising into the sky will block the sun, leading to a drop in the average temperature of the earth.

For another example, the melting of glaciers in the Antarctic and Arctic will bring a lot of fresh water to the ocean, thus weakening the role of ocean currents, thus disrupting the existing ocean temperature cycle, thus bringing about cooling and extremely cold climate, thereby increasing the glacier area. The American film "The Day After Tomorrow" borrowed this speculation about ocean and climate change and made a Hollywood-style extreme display.

Weather forecast, it is very difficult to accurately predict the weather in a month. It is still very difficult to predict the marine environment after 80 years by relying on the existing data model.

However, reducing environmental pollution, reducing emissions and trying to reduce the impact of human beings on the environment is still a positive attitude of human beings in the face of the unknown. However, don't worry too much about sea level rise. If it does happen, it must be that the South Pole and the North Pole were bombed by nuclear bombs, or the earth was attacked by the solar wind ... Humans can't escape, so don't worry about anything.

It's not easy for urbanites, and they are under great psychological pressure. There is no need to put more pressure on them.

PS: At present, there are area data and real glacier volume, but the data is still quite lacking. In fact, we don't know how much water glaciers can bring, and whether these water will evaporate, turn into rain and land, or form water vapor, thus reducing the energy of sunlight falling and cooling the earth.