2020 "Physical Examination" Report: The Arctic is performing "Song of Ice and Fire"

　　Today's viewpoint

　　The US "Science" magazine reported on the 14th that according to the latest assessments jointly reported by the National Aeronautics and Space Administration, the British Meteorological Administration and other agencies, the earth's temperature is generally about 1.25°C higher than the pre-industrial era.

Berkeley Earth, one of the monitoring organizations, reported that land temperature in 2020 will set a new record, 1.96°C higher than the pre-industrial level.

　　Not long ago, the National Oceanic and Atmospheric Administration (NOAA) of the United States issued an annual Arctic climate report-the Arctic Report 2020.

If the Arctic is a "patient", then this report is the result of a comprehensive "physical examination" of the health of this huge and important biome: temperature is rising, ice is melting, snow is disappearing, and the fragile ecosystem in the Arctic is rapidly evolving .

According to reports, the North Pole is no longer the North Pole decades ago, and in a few decades, it will no longer be the same.

　　At present, the temperature in the Arctic is rising at least twice as fast as the global average; at the same time, the Arctic is performing a "Song of Ice and Fire": the Arctic Ocean is warming, the melting of Greenland’s ice sheet is accelerating, and the entire tundra every summer Wildfires are raging...

　　Sea ice "air conditioning" is collapsing

　　Scientists say that the Arctic is the "leader" of global climate.

The earth heats up due to the greenhouse gases emitted by humans. The Arctic first felt the effects of this warming, which indicates that changes will also occur in the climate zone of lower latitudes.

　　At the end of the summer melting season, Arctic sea ice usually reaches its lowest value in September.

According to the report, sea ice in the eastern Siberia and the Laptev Sea (one of the continental marginal seas of the Arctic Ocean) area began to melt earlier in the spring of 2020, setting a new low in the Laptev Sea in June.

In 2020, the extent of summer sea ice hit the second lowest in 42 years of satellite records, second only to the summer of 2012.

When the temperature drops in autumn, the sea ice freezes later than usual.

　　Scientists said that a record low sea ice area appeared the year before, indicating that this "air conditioning" system is collapsing.

　　Walter Meyer, a senior researcher at the US National Ice and Snow Data Center, said that it is no longer a question of "whether" we will see an ice-free Arctic in the next few decades, but a question of "when".

　　Wildfires are raging and the Arctic turns green

　　Last year was a record summer for wildfires in the Arctic Circle.

This is mainly due to fires in Siberia, especially in the Sakha Republic, which borders the Laptev Sea.

　　According to data from the Copernicus Climate Change Service Center, as of June, wildfire activity in Siberia has broken last year's record, and high temperatures and abundant dry fuel are largely to blame.

　　Most of the dry fuel that fuels the Arctic fires comes from dead moss and other plant matter accumulated in the soil.

Freezing temperatures tend to prevent these dead plants from rotting completely in winter, and when the ground melts in spring, they will quickly dry out.

The warmer the air, the earlier the spring, and the faster they dry.

　　In addition, since the early 1980s, satellites have been tracking the vegetation of the tundra or the "greenness" of the Arctic, which is an important signal of climate change in the Arctic.

Since 2016, the "greenness" of North America has dropped sharply, but it is still above average in Europe and Asia.

　　The report found that from the complete satellite record, the Arctic is generally moving in a more "green" direction, as the temperature rises melting the frozen tundra, and shrubs and other plant species begin to grow in places where they could not take root in the past.

　　The ecosystem is a bit "abnormal"

　　Climate change is also affecting the flora and fauna of the Arctic Ocean, starting at the bottom of the food chain.

　　Tiny algae are the cornerstone of the Arctic marine ecosystem.

Every spring, when the sea ice melts and the ocean is full of sunlight and nutrients, algae begin to grow rapidly, providing plenty of food for other animals in the Arctic Ocean.

　　With the warming of the Arctic and the thinning of sea ice, the range of seaweeds has grown larger and appeared earlier.

There was even a second outbreak in some places in the fall.

Karen Frey, an expert on Arctic issues at Clark University in the United States, said this is a "relatively new" phenomenon.

　　The extra food is a boon to some animals in the Arctic Ocean.

Last year's Arctic "medical examination" report stated that the number of bowhead whales in the Arctic has recently increased.

Scientists believe that these changes may be related to increased algae.

　　When sea ice melts, the seaweeds that grow on the sea ice often fall to the bottom of the sea and become food for seabed creatures such as shellfish, sea urchins, and sea cucumbers.

But Frey warned that the melting of sea ice also meant to some extent that the "seaweed delicacy" of certain organisms was reduced.

　　Earlier, there were also reports that permafrost covered 24% of the earth’s land surface.

Some frozen ground in the Arctic may contain ancient frozen microorganisms, glacial giant animals, and even buried smallpox victims.

As permafrost is melting faster and faster, scientists are facing a new challenge to discover and identify microorganisms, bacteria, and viruses that may be "stirring".

　　In August 2019, Iceland held a funeral for Okyol Glacier, the first glacier lost due to climate change.

Iceland uses a nameplate to "commemorate" this irreversible change and the serious impact it represents.

This funeral is a ritual, but also a vigilance.

To curb the speed of climate change, it is urgent to protect the environment.

　　The 2020 Arctic "Physical Examination" report has made scientists feel that the pace of change in the Arctic has far exceeded expectations in the past 20 years, especially the past 5 years.

James Overland, an oceanographer at NOAA’s Pacific Ocean Environmental Laboratory, said: “The potential changes in the Arctic are three times what we see in mid-latitudes. This will completely change the appearance of the Arctic and provide feedback to the Earth’s other areas."

　　These changes and impacts should cause us to pay enough attention. The Arctic is sick, and we must fight this for a long time to come.

　　◎Intern reporter Zhang Jiaxin