Climate Change Influences River Flow
Climate change is affecting the water balance of our planet: depending on the region and the time of year, this can influence the amount of water in rivers potentially resulting in more flooding or drought. River flow is an important indicator of water resources available to humans and the environment. The amount of available water also depends on further factors, such as direct interventions in the water cycle or land use change: if, for example, water is diverted for irrigation or regulated via reservoirs, or forests are cleared and monocultures grown in their place, this can have an impact on river flow.
However, how river flow has changed worldwide in recent years was so far not investigated using direct observations. Similarly, the question whether globally visible changes are attributable to climate change or to water and land management had not been clarified.
Now, an international research team led by ETH Zurich has succeeded in breaking down the influence of these factors, after analysing data from 7,250 measuring stations worldwide. The study, which has been published in the scientific journal Science, demonstrates that river flow changed systematically between 1971 and 2010. Complex patterns were revealed – some regions such as the Mediterranean and north-eastern Brazil had become drier, while elsewhere the volume of water had increased, such as in Scandinavia.
Climate Change in Siberia
Global warming is something of a boon for Russia, where 55% to 65% of the country is covered in permafrost. It is estimated that 60% of the country’s oil and 90% of its natural gas, as well as deposits of nonferrous metals and gold, lie under this thawing part of the planet.
President Vladimir Putin once shrugged off the perils of global warming, saying, “an increase of two or three degrees wouldn’t be so bad for a northern country like Russia. We could spend less on fur coats, and the grain harvest would go up.”
That was at least partially prophetic. According to Russia’s Federal State Statistics Service, grain production in 2020 was up 9.7% from the previous year, the second highest level after 2017. The amount of land under cultivation is also increasing.
But those shrugged-off perils are beginning to overshadow the bumper harvests.
In the Republic of Sakha in far eastern Siberia, the temperature is minus 50 C, yet white smoke rises from the snow-covered ground. In January, local media released an amazing image of a peat fire in the ground under the snow.
Roughly 140,000 sq. km of Russia, about the size of Greece, was lost to fire in 2020. Most of that was in once-frozen areas. When covered with snow in winter, the fires seem to be extinguished. However, the peat in the ground continues to smolder, and in summer it ignites on the surface. They’re being called zombie fires and are believed to be caused by global warming.
In Siberia, plants and other organisms that have been decomposing for more than 10,000 years are trapped in the soil as CO2 and methane gas. These gases are released by fires and other events, further accelerating global warming. The world’s permafrost zones are thought to contain twice the amount of carbon that is in the atmosphere.
In 2016, western Siberia experienced a different kind of crisis, an anthrax outbreak. One boy and over 2,000 reindeer died. The source of the bacterial infections was the melted corpse of a reindeer that had been frozen for more than 75 years. Some scientists have warned of the possibility of more dormant pathogens reactivating.
Although it was supposed to be a global warming “winner,” Russia has become an unexpected climate change victim.