California wildfires 2020

from Wikipedia, the free encyclopedia
Forest on fire, Doe Fire
Visual conditions in San Francisco with Bay Bridge at noon, September 9th

The California wildfires in 2020 are a series of forest fires in the US - State of California . They began in the summer of 2020. On September 16, around 13,000 km² of forest had been destroyed. On September 9th there were still about 2.5 million acres (about 10,000 km²); around 20 times as much space as in the previous record year 2018 at this time. At the beginning of September, more than 8000 km² of forest had been destroyed; more than any other season since records began in the late 1980s. In historical comparison, the extent of the fires occurred extraordinarily early; usually September and Octoberthe months with the strongest fires .

A total of around 7600 different fires had been reported at this time, which were favored by a prolonged drought and strong winds. More than 4,200 buildings were destroyed, at least 25 people were killed, and more are missing. There were mass evacuations . With the SCU Lightning Complex , the LNU Lightning Complex and the August Complex , three of the four largest fires ever observed in the history of California burned in parallel at the beginning of September. The August Complex is the largest fire ever registered in California and, with the LNU Lightning Complex in fourth place in terms of area, is also one of the ten most destructive fires in California's history. By September 11th, August Complex had destroyed an area of ​​more than 3,000 km².

The 2020 forest fire season was already considered the worst on record in mid-September. Due to the simultaneous occurrence over a very large area and the enormous speed with which they increased in size, the fires have been described as unprecedented in recent (American) history, only comparable to the Great Fire of 1910 in Montana and Idaho .

course

Satellite image of the cloud of smoke over the states on the US west coast and over the Pacific Ocean

After a hot spring had dried out the vegetation and the summer months of 2020 were also hot and dry, a heavy fire season was expected. The first series of severe fires broke out in mid-August after violent thunderstorms with almost 11,000 lightning strikes occurred in California within three days. On August 18, the called Governor Gavin Newsom the emergency from. A second major wave broke out in early September when parts of California were hit by a massive heat wave that broke various records. Various fires also took on an enormous size within a short period of time. So z. B. the Bear Fire north of Sacramento overnight around 230,000 acres (approx. 920 km²).

The fires were fanned by strong, dry winds from the sea, which contributed to the occurrence of exceptional fire conditions. Among other things, these led to the formation of about 12 km high, mushroom-shaped smoke clouds as well as fire tornadoes , which make it almost impossible to contain the expanding fires. As a result of the drought in California in 2011–2017 , which was one of the main reasons for the death of around 163 million trees , there was also a great deal of easily combustible material available.

As of September 16, around 16,000 firefighters were fighting the forest and bush fires. In addition to fire brigade units from other states, a. also requested forces from Israel . Extinguishing is made more difficult by the fact that many other states in the western United States from Utah and Colorado to Montana are also affected by severe fires, which means that fire brigades are overloaded and supraregional fire fighting is hardly possible. Typically, Arizona and New Mexico have most fires in late spring and early summer, while California's fire season begins in late summer and then extends through fall. Severe fires also broke out in the states of Oregon and Washington , north of California, which affected an area of ​​672,000 and 500,000 acres (approx. 2700 and 2000 km², respectively) as of September 10, 2020.

causes

The cause of the severity of the fires in the entire western United States is considered to be a strong wind event in the northwest, a record heatwave that was replaced by windy conditions, and climate change , which dries out the vegetation due to higher local average temperatures and thus makes it more susceptible to fires as a result von Funkenschlag. Although it is difficult to attribute individual fires to climate change, it does lead to rising temperatures and changes in precipitation patterns. This is accompanied by higher temperatures and more severe droughts , which in turn promote fires. Among other things, there was significantly below-average rainfall in winter 2019/2020, while there was a strong heat wave in summer , in which, among other things, the highest temperature recorded on earth was 54.4 degrees Celsius. August 2020 was the hottest August ever recorded in California; 34 of the 58 counties broke temperature records. The highest temperature rises were recorded in the counties of Alameda , Contra Costa and San Joaquin , in which the SCU Lightning Complex fire burned from August 18.

A number of well-known climatologists emphasized that the California forest fires would very likely not have occurred in this form without the climate crisis . Allocation researcher Friederike Otto , head of the Environmental Change Institute at the University of Oxford, stated: “There is no doubt that the extremely high temperatures are higher than without the human-made climate changes. Much of the mapping literature now shows that climate change is an absolute game changer in terms of heat waves, and California will be no exception. " David Romps , director of the Berkeley Atmospheric Sciences Center, said similarly:" To get to the point : Were the heat wave and the thunderstorms and the dryness of the vegetation affected by the global warming? Definitely yes. Have they been made significantly hotter, more numerous, and drier because of global warming? Yes, probably yes and yes. "

The historical trends indicate that man-made climate change has already created conditions that increasingly favor the development of forest fires. This trend is likely to intensify as global warming proceeds. Between 1972 and 2018, the burned forest area in California increased by a factor of 8, while the local temperature rose by approx. 1.4 ° C, thereby increasing the saturation deficit of the air. The clearest evidence of the connection between man-made climate change and increasing forest fires is the increased drying of fuel due to higher temperatures. From around mid-August to mid-September 2020, the saturation deficit in California and other US states on the west coast was higher than ever in the past 40 years during this period.

Air pollution and health

Heaven over Eureka

The forest fires caused enormous clouds of smoke that resulted in heavy air pollution and darkened entire cities such as San Francisco during the day . As a result, millions of people, especially the elderly and people with previous illnesses, are exposed to acutely harmful levels of air pollutants. This exacerbates the tension in the U.S. healthcare system caused by the COVID-19 pandemic , given that air pollution can make symptoms of COVID-19 more difficult. In some regions the air quality reached the lowest level “dangerous”. As a result of smoke pollution, air pollution in San Francisco and Los Angeles, as well as other cities on the west coast of North America, increased so much that they were counted among the ten cities with the highest air pollution in the world. Sometimes there was ash rain.

The clouds of smoke moved over long distances, mostly on the west coast, but were also visible in New York City , on the US east coast. In Switzerland , too , the smoke was measurable and could be seen with the naked eye through a stronger orange color at sunrise and sunset.

See also

Web links

Commons : California Forest Fires 2020  - Images, Videos and Audio Files Collection

Individual evidence

  1. ↑ a b c d Climate change fuels US forest fires, but not alone . In: Tagesspiegel , September 16, 2020. Retrieved September 16, 2020.
  2. ↑ a b c d Wildfires Bring New Devastation Across the West . In: The New York Times , September 9, 2020. Retrieved September 10, 2020.
  3. ↑ a b Record area forest burned in California . In: Spiegel Online , September 9, 2020. Accessed September 10, 2020.
  4. ↑ At least 26 dead in fires in western America . In: Frankfurter Allgemeine Zeitung , September 12, 2020. Retrieved September 12, 2020.
  5. ↑ Three recent wildfires now among top 4 largest in California history: See Cal Fire list . In: San Francisco Chronicle , September 4, 2020. Retrieved September 10, 2020.
  6. ↑ a b c d Western wildfires break records as devastating toll on lives and homes begins to emerge . In: Washington Post , September 10, 2020. Retrieved September 11, 2020.
  7. ↑ a b A gigantic catastrophe . In: Süddeutsche Zeitung , September 11, 2020. Retrieved September 11, 2020.
  8. ↑ California wildfires: Thousands evacuate as 'siege' of flames overwhelms state . In: The Guardian , August 20, 2020. Retrieved September 10, 2020.
  9. ↑ California Wildfires: Extreme Heat Turns State Into a Furnace . In: The New York Times , September 9, 2020. Retrieved September 10, 2020.
  10. ↑ A Climate Reckoning in Fire-Stricken California . In: The New York Times , September 11, 2020. Retrieved September 11, 2020.
  11. ^ A Siege of 80 Large, Uncontained Wildfires Sweeps the Hot, Dry West . In: Inside Climate News , September 9, 2020. Retrieved September 10, 2020.
  12. ↑ Three dead in Northern California and five destroyed small towns in Oregon, orange smoke over San Francisco - the latest developments in the forest fires in the USA . In: Neue Zürcher Zeitung , September 10, 2020. Accessed September 10, 2020.
  13. ↑ How Record-Smashing Heat Ushered in Western Infernos . In: Scientific American , September 11, 2020. Retrieved September 11, 2020.
  14. ↑ What Is Causing Those Fires And Blackouts In California? Could It Be (Gasp!) Climate Change? . In: Cleantechnica , August 22, 2020. Accessed September 11, 2020.
  15. ↑ Michael Goss et al .: Climate change is increasing the likelihood of extreme autumn wildfire conditions across California . In: Environmental Research Letters . tape 15 , no. 9 , 2020, doi : 10.1088 / 1748-9326 / ab83a7 .
  16. ↑ A. Park Williams et al .: Observed Impacts of Anthropogenic Climate Change on Wildfire in California . In: Earth's Future . tape 7 , no. 8 , 2019, pp. 892–910 , doi : 10.1029 / 2019EF001210 .
  17. ↑ title . In: The Washington Post , September 11, 2020. Retrieved September 12, 2020.
  18. ↑ Wild fires blot out sun in the bay area . In: The New York Times , September 9, 2020. Retrieved September 10, 2020.
  19. ↑ Why wildfire smoke can turn the sky orange and damage your lungs . In: Vox , September 9, 2020. Retrieved September 10, 2020.
  20. ↑ Fires in the USA stir up fear of climate change . In: Süddeutsche Zeitung , September 14, 2020. Retrieved September 14, 2020.
  21. ^ Forest fires on the US west coast: smoke as far as New York . In: ORF , September 16, 2020. Retrieved September 16, 2020.
  22. ↑ Fires continue to rage, fire at historical observatory contained - the latest developments on forest fires in the USA . In: Neue Zürcher Zeitung , September 16, 2020. Retrieved September 16, 2020.