Last year was extremely hot andarid, as a result of thermal domes, temperatures in some regions broke records. In particular, the western United States was affected, where a serious drought arose. However, according to experts, one should not expect that the situation will change in the near future. The region can expect the worst drought in the last 1200 years (in fact, in the entire history of observations), which will last until 2030. I must say that the problem associated with a lack of moisture arose more than 20 years ago, but there were occasional breaks. For example, 2011, rich in precipitation, pleased and gave hope to farmers. There was not a lot of rain in 2019, but they were compensated by heavy snowfall in winter. Now experts expect the drought to continue without interruption. The reason for this, in their opinion, is global warming. True, it is quite possible that drought would have occurred without human activity, since dry periods are typical for the region. However, the situation would not be so critical. According to one recent study, drought will be increased by 40% as a result of global warming.
- 1 The worst droughts in the US in the last 1200 years
- 2 Drought in the US breaks records
- 3 Global warming exacerbates drought
- 4 When will the drought end in the US?
The worst droughts in the US in the last 1200 years
A feature of the climate in the western United States has always beenits instability. Periods of heavy rainfall are regularly replaced by dry months or even years. At the same time, American scientists are constantly monitoring the situation, as a large number of people live in the region. In 2020, climatologist Park Williams of the University of California, Los Angeles, conducted a study with his colleagues that studied regional drought over the past 1,200 years. Tree rings were the main source of climate information.
In years when there is a large amountrainfall, the annual rings are thick, as the trees are actively growing. In stressful years, when there is little moisture, the rings, respectively, are thin. Trees during this period try to save moisture, so they do not spend it on growth.
Researchers have studied tree rings for more thanone and a half thousand trees in the western United States, many of which were about 800 years old and even more. As a result, they were able to find out that in the period from 800 to 2018 there were 40 droughts, four of which were extremely severe, the so-called “mega-droughts”. The first arose in the late 800s, and there were also severe droughts in the mid 1100s and 1200s. But the fourth megadrought, which lasted from 1575 to 1593, turned out to be the strongest.
Drought hits records in the US
When scientists published their analysis, it wasit is clear that the current drought in 2018 is far from being the worst. For example, in the 1500s, the situation was more serious, and it lasted longer. Since 2019 was a rainy year, experts hoped that the dry period was over.
But as it turned out, 2019 was just an exception.not a change in the dry period. The subsequent years 2020 and 2021 were even worse than 2018. For example, the summer of 2021 saw record heatwaves that sucked every trace of moisture out of the soil and drained reservoirs so much that many farmers found themselves without water to irrigate their crops at all. As a result of the drying up of large reservoirs along the Colorado River, water consumption in the states of Arizona and Nevada has been reduced.
When Park Williams and colleagues added to theiranalysis of data in recent years, it became quite clear that the current drought is the driest on record, although not yet the longest. Several previous megadroughts have lasted longer. At the same time, 2021 was the driest year in the last 300 years.
Global warming exacerbates drought
The team found that climate change,caused by human activity has turned the drought “from bad to terrible”. That is, if it were not for global climate change, these would be typical dry years for the region. However, as a result of warming, the climate has become hotter and drier, so the soil has lost much more moisture. According to experts, 2021 alone is about 20 percent drier than it could be.
Also, according to experts, climate changehas been responsible for about half of the loss of water in the Colorado River in recent years. At the same time, the risk of fire has risen sharply. Average temperatures have already risen by about 1.1 degrees Celsius since the late 1800s. Temperatures are predicted to rise even more in the coming decades.
When will the drought end in the US?
No one can say for sure when it will end.this drought. But, judging by the history of past droughts, sooner or later it will happen anyway. But the problem is that, unlike the situation of past years, it will be much more difficult to eliminate the deficit of soil moisture in the context of global warming.
“The inertia of a drought of this magnitude is unlikely to be broken in one year of good rainfall. It will take several rainy years for the soil to absorb enough moisture.” Park Williams says
This is extremely bad news for many.farmers who have been waiting for years for a change in the current situation. To estimate when the region will emerge from the ultra-dry phase, the research team studied the wet and dry period patterns described in their study. They then overlaid this historical data on the current state.
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As a result, the team concluded that evenassuming no climate change, the drought could last until 2023. Under current conditions, simulations have shown that the drought has a 75% chance of continuing until 2030. But, the worst thing is not even that. The fact is that the next phases of the drought will be even stronger and longer. That's why some experts say that global warming could be more dangerous for people than the coronavirus pandemic.