Siberian tundra may disappear completely by 2500 due to global warming. To prevent this from happening, it is necessary to reduce greenhouse gas emissions, which accelerate climate change, according to Live Science..

Even under the most optimistic scenario, two-thirds of the local landscape with a short growing season and a cover consisting mainly of grasses, mosses, shrubs and lichens will disappear, leaving behind two fragments separated by 2500 kilometers. Melting tundra permafrost will release greenhouse gases bound in it, further accelerating climate warming.

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“We were stunned at how quickly forests can replace tundra,” said an environmentalist from the Center for Polar and Marine Research.. Helmholtz of the Alfred Wegener Institute Stefan Kruse. The disappearance of the tundra will not only harm biodiversity and human culture, but may exacerbate warming in the Arctic, which is already going twice as fast as in other regions of the planet.

Between 1960 and 2019, temperatures in the Arctic region rose by an average of four degrees Celsius.. This has led to a decrease in sea ice and has affected the Arctic landmass.. One of the consequences of rising temperatures is the expansion of forests to the north.

How quickly such forests can replace the herbaceous-shrub ecosystem of the tundra is unknown.. According to Kruse, the change in the line of forests in response to global warming is not the same around the world.. In some regions, the trees moved north, in others they remained in place.. Previous tundra surveys have been limited to small areas, but circumstances may vary from site to site..

Now Kruse and his colleague Ulrike Hertzshu have created a new computer model that has estimated the entire expanse of the Siberian tundra with a length of 4000 kilometers.. This model takes into account the life cycle of individual trees, from how far they can plant seeds to how well they grow when faced with competition from other trees.. In addition, the growth rate is taken into account depending on temperature, precipitation and the depth of summer permafrost thawing..

It turned out that when trees start to move north in response to global warming, they do it quickly.. Moreover, they are unlikely to retreat if the temperature drops again.. In a scenario in which carbon emissions are reduced to zero by 2100 and temperature rises halt to within 2 degrees Celsius, only 32.7% of today's tundra will remain by 2500. And it will be divided into two mini-tundras: one in Chukotka, one on the Taimyr Peninsula.

But even this scenario may not be achievable unless important action is taken very quickly.. This means that the result of climate change for the tundra can be much more deplorable.. In an average scenario in which carbon emissions are not reduced until 2050 and are halved by 2100, only 5.7% of the current tundra area will remain unforested by 2500.

In a faster warming scenario, trees could move up to 30 kilometers north. When scientists modeled a cooling climate followed by a warmer climate, they found that the trees would not recede as quickly as they advanced.. Kruse emphasizes that once mature trees are established, they can withstand a lot..

The researchers did not directly model how shrinking the tundra would affect its inhabitants, such as reindeer.. But living in two populations separated by space that interferes with interbreeding tends to be bad for the species.. Reindeer migrate from north to south and back throughout the year, it is not known how the spread of forest will affect these migrations.

People will feel the consequences. Indigenous peoples such as the Nenets herd and hunt reindeer. According to Kruse, the loss of the tundra could affect the culture of these peoples..

How the disappearance of the tundra will affect the future of global warming is also unclear.. But covering mossy, scrubby meadows with trees can make matters worse.. The snow-covered tundra is lighter than the canopy of a deciduous forest. That is, the forest will absorb more heat, which could make the Arctic an even hotter place.. And that extra heat could exacerbate the melting of the tundra's permafrost, which holds huge amounts of greenhouse gases.. Melting will release them and also wake up bacteria and viruses..

Change is likely to go beyond simply replacing the tundra with deciduous forests.. As more and more permafrost melts during hotter summers, evergreen trees will also migrate..

They remain leafy all year long, absorbing even more heat than leafy ones.. The south side of the taiga, where temperatures are already warmer than the north, is likely to warm even more, leading to drought and wildfires that release even more carbon into the atmosphere..

Earlier, the World Meteorological Organization (WMO) said that there is a chance that the average temperature on the planet will reach 1.5 degrees above pre-industrial levels in the next five years.. These odds are about 50/50..