What are the Risks of Fires in the Amazon?
The fires in many parts of Brazil's Amazon area have brought an internationaloutcry to save the world's largest rainforest.
Wealthynations have offered Brazil at least $22 million to fight the fires. ActorLeonardo DiCaprio also offered $5 million for efforts to save the forest.
Duringthe recent G-7 meeting in Biarritz, France, French President Emmanuel Macroncommented on the fires. He told leaders meeting there that the world cannotpermit Brazil to destroy what he called the "lungs of the planet."
What's in the Amazon?
TheWorld Wildlife Foundation (WWF) says the world'slargest rainforest contains millions of species of plants and animals. Many ofthem are still unknown. Among the best known animals are jaguars, eagles, pinkriver dolphins, parrots, large snakes and many butterflies.
TheWWF says the forests contain over 40,000 kinds of plants and the 6,500 kilometers of rivers contain 3,000 kinds of freshwater fish.
Thearea drained by the Amazon River covers 40 percent of South America. The forestextends over seven other countries and a French territory.
Morethan 30 million people, including 350 indigenous and ethnic groups, live in the Amazon area and depend on the forests for food and shelter.
Is the Amazon the lungs of the planet?
Therainforest is often called the "lungs of the planet." But that might not be the best way to describe the area's importance to the world's ecosystem.
CarlosNobre is a University of Sao Paulo climate scientist. He said a better way tothink about the Amazon's role is as a sink, taking heat-trappingcarbon dioxide, or CO2, from the atmosphere.
Currently,the world is releasing around 36 billion metric tons of CO2 into the atmosphereevery year. And the Amazon absorbs about five percent ofthe CO2 making it important in preventing climate change.
Will the Amazon produce less oxygen for the planet?
Whileit is often said that the Amazon produces 20 percent of the world's oxygen,climate scientists say that is not the case.
They say forests, including the Amazon, absorb about the same amount of oxygen asthey produce. Plants produce oxygen through a process called photosynthesis,but they also absorb it to grow, as do animals and microbes.
Scientistssay the world's oxygen supply is not directly at risk from the fires. However,that does not mean the fires are not a problem. The Amazon forest also absorbs other heat-trapping gases produced by burning fossil fuels, like oil and coal.
What do the fires mean for the world's climate?
The fires not only destroy parts of the carbon-absorbing forests, but they releasemillions of metric tons of carbon into the air.
The Amazon rainforest also is important to rainfall in the area. Deforestationmakes rains less frequent, extending the dry season.
CarlosNobre estimates that if 20 to 25 percent of the forest were destroyed, the dryseason would expand. That would mean the area would no longer be a rainforest,but a tropical savannah, or an area with grasslands and few trees.
Nobreadded, "Unfortunately, we are already seeing signs of the Amazon turninginto a savannah."
What is causing the fires?
The current fires in the Amazon are not wildfires. They are mostly set illegally by people who are clearing the forest to raise cattle and crops.
People clear the land by cutting down the trees during the rainy season, letting thetrees dry out and burning them during the dry season. Fully clearing the thick forest for agricultural use can take several years of cutting and burning.
NASA researcher Doug Morton said researchers could see piles oftrees months ago in satellite images. He said, "They're burning anenormous bonfire of Amazon logs that have been piled, dryingin the sun for several months."
Nobresays Brazil's policy has changed under President Jair Bolsonaro. The newpresident has limited the power of forest protection agencies saying they getin the way of developing land.
Nobreadded, "The number of fires increasing is because people think lawenforcement won't punish them."
1.ethnic groups 民族
There are 56 ethnic groupsin China.
2.turn into 成为，变为
People are turning intomachines nowadays.
3.satellite image 卫星图
high-definition satellite image