The article is from the public number: Global Science (ID: huanqiukexue) , Compilation: Zhang Erqi, the title picture comes from: worm creative.
31 December 2019In the morning, people in the town of Marakuta took refuge on the coast.
It is 9 am on December 31, 2019, but the sky is still dark. The temperature has exceeded 40 degrees Celsius, and the air is filled with uncomfortable smoke. The approaching fire cut off all roads on land, and residents and tourists in the town had to flee to the coast, waiting for rescue.
This is not the plot of the doomsday movie, but a real scene that takes place in the town of Marakuta, Victoria, Australia. The raging forest fire finally arrived in this tourist town on December 30. With the help of the Australian Navy, more than 1,000 residents and tourists successfully evacuated by boat on New Year’s Eve.
Deadly Mountain Fire
Since last September, wildfires have occurred in various parts of Australia, and the fire is still spreading. Compared with previous years, this fire has spread to 6 Australian states and has killed 24 people, including several firefighters. Its severity is unprecedented in history.
Bateman Bay, Australia December 31, 2019 Hillfire. (Image source: Copernicus EMS; Sentinel 2 / ESA)
According to CNN’s (CNN) , as of January 5, there are more than 5.9 million hectares across Australia. (equivalent to 59,000 square kilometers) The land was burned and its area is close to half of England. In Australia’s historical records, there are only a handful of wildfires that have destroyed millions of hectares. And according to the United StatesNASA (NASA) satellite monitoring data, the 2019 Amazon rain forest fire burned about 1.8 million hectares of forest area; severe drought in California caused The severe mountain fire burned an area of about 800,000 hectares.
Australian Mountain Fire on November 1 (a), November 14 (b), December 5 (c), December 26 (D) Distribution. (Image source: BBC News)
Of the states, the worst hit was New South Wales. As of January 3, there were more than 130 wildfires across the state of New South Wales, of which more than 60 were still not effectively controlled. About 3.6 million hectares of land in the state were burned, more than 1,300 houses were damaged, of which 440 were completely destroyed and thousands of residents were displaced. In December, parks, trails and campsites in New South Wales were urgently closed.
Satellite images show fires in Victoria and New South Wales. (Image source: RAMMB / CIRA / CSU)
The fire caused extreme heat and poor air quality. According to CNN, fires destroyed houses in Sydney’s suburbs, and heavy smoke shrouded the city centre. Air pollution in Sydney last DecemberContamination reached 11 times the “dangerous level” (hazardous level, that is, the air quality index exceeds 300) . In the thick smoke, the famous Sydney Opera House can only see the outline.
The Sydney Opera House hidden in the smoke. (Image source: Bianca Britton)
Other states in Australia are also suffering. In Victoria alone, more than 800,000 hectares of land have been burned. There is no major fire in the Australian capital Canberra, but smoke from New South Wales has caused dangerous air pollution and killed one person.
Vast residents of Victoria and New South Wales are fleeing. (Image source: CNN)
The fire has begun to affect neighboring countries. Satellite images show that smoke from the fires in Victoria and New South Wales has affected New Zealand.
Satellite images show smoke from the fire blowing into New Zealand. (Image source: RAMMB / CIRA / CSU)
Ecological loss
The ongoing fire has caused serious damage to the local ecological environment. According to the Australian Federal Environment Minister (Australian Federal Environment) Minister Sussan Ley, It is estimated that the fire caused NSW 1 / Three Koalas died, and one-third of all habitats were completely destroyed.
Koala who failed to escape from the fire in time and eventually lost his life
Opossum injured in a fire. (Image source: REUTERS)
According to Chris Dickman, a professor of ecology at the University of Sydney, as of the end of December, about 480 million animals, including mammals, birds and reptiles, have been affected by the fire in New South Wales alone. He said that although many animals with high mobility, such as kangaroos, tapirs, and other birds may survive the fire, whether they can survive due to loss of food and shelter is still a problem.
Kangaroo fleeing the fire. (Image source: MATTHEW ABBOTT / NEW YORK TIMES / REDUX / EYEVINE)
Natural or man-made disaster
In Australia, every summer (January to February) , there are mountain fires, which is also known as “mountain fire season” span class = “text-remarks” label = “Remarks”> (bushfire season) . On the one hand, the hot and dry summer weather makes it easy for fires to spread and spread. On the other hand, some plants in Australian forests have evolved the “hidden fire” habit, which also makes forest fires particularly prone to occur. For example, the local dominant tree species-eucalyptus-is flammable, but its growth rate is very fast, and its seeds are also resistant to high temperatures. The fire can help them destroy other competitors, and after the fire, its seeds can grow new shoots and quickly grow into large trees.
For the cause of the fire, most cases are “sky fire”, which is a natural cause, such as lightning hitting a dry forest. Data from Victoria Emergency Services Agency (Victoria Emergency) In late December last year, lightning fell into the Gippsland area in eastern Victoria, and the fire spread over 20 kilometers in just 5 hours.
But there are also “human disasters” for the cause of the fire. Sometimes the farmer chooses to use the fire to clear the field. Once the operation is wrong, a mountain fire may be caused. There is also the phenomenon of deliberate arson. For example, a 19-year-old arsonist was arrested by the Rural Fire Station of New South Wales in November. According to investigations, he has deliberately arsoned several times during the six-star period.
A wildfire occurs in Australia almost every year, and this year’s extraordinarily long and severe fire is considered to be related to the exceptionally hot and dry climate of 2019.
Australian Government Bureau of Meteorology according to the Australian Meteorological Bureau’s
Average map of annual average temperature in Australia
The hot and dry conditions make the forest more flammable, and the accompanying strong winds make the fire and dense smoke spread faster. Coupled with more frequent thunderstorms, the risk of fire is further increased.
So is this fire related to global climate change? This is actually a complicated issue.
Climatologists have long warned that hotter and drier climates will increase the frequency and severity of fires. In fact, Australia has had less precipitation in recent years, which has made it easier for fires to spread.
Meteorological Australia (Bureau of Meteorology) Senior meteorologist Andrew Watkins said that the main climatic driver of the abnormally high temperature in Australia in recent years is the Indian Ocean dipole (Indian Ocean Dipole, IOD) enhancements. IOD will cause higher surface seawater temperature in the western Indian Ocean and lower surface seawater temperature in the eastern Indian Ocean. The IOD enhancement in 2019 caused the temperature difference between the two to reach a maximum of nearly 60 years. As a result, large amounts of precipitation and floods occurred in Africa on the west coast of the Indian Ocean, while Southeast Asia and Australia on the east coast were extremely dry and hot.
The picture shows the Indian Ocean, with its west coast being Africa, and its east coast being Southeast Asia and Australia. The blue area indicates that the sea surface temperature is lower than the historical average, and the red area indicates that the sea surface temperature is higher than the average.
What will happen in the future
Although the Australian wildfires have caused serious losses, we still do not know when the fires will be brought under control. At present, Australia has just entered the summer. According to previous experience, the temperature and drought will reach their peaks in January and February, so the fire is likely to continue to spread.
The Australian government has organized a fire department to fight the fire, but it is difficult to effectively control such a severe fire due to the number of people and the level of equipment.
After the fire, Queensland briefly declared a state of emergency in November, and NSW also declared a state of emergency in December. The power to allocate government resources and direct government agencies to take action. More than 2,300 firefighters are currently in NSW