The flames and smoke of the most devastating wildfires for almost a decade in the Amazon Rainforest caught belated attention to a key issue – how are such fires ignited? In temperate forests, forest fires, which catalyse reproduction of Sand Pine (Pinus clausa) by heating up the cones to release their seeds, are considered as natural phenomena due to scanty rainfall. Yet, most of forest fires, either in the "Earth’s Lungs" or the "Pearl of the Orient", are set deliberately.
Around 60% of the Amazon Rainforest is on Brazilian land. Figures show that this year, the area of forest fire has soared by 80% since the same period last year; the number has reached a record high of 70,000 cases. Certainly, the hot and dry weather arising from global warming can naturally kindle bushfires. However, more evidence is proving that Jair Bolsonaro, the new president of Brazil, is the unspoken culprit. The nation’s top official has been accused of turning a blind eye to farmers who raze the rainforest to the ground, for crops and cattle farming. The cheap deforestation tactic is widely applied by farmers, lighting incessant fires that consequently ran out of control.
Yadvinder Malhi, Professor of Ecosystem Science at Oxford University, pointed out that the Amazon encountered a long fire season in 2016 due to a record-breaking drought. However, records show that rainfall was abundant this year. The earthly inferno was undoubtedly man-made.
Some 2,700km away from the basin, the sky of São Paulo was cloaked with suspended particles emitted from the blaze. “Black rain” fell from the gloomy clouds that no single ray of sunlight could penetrate. Scientists warned that the Amazon fire may alter the global rainfall pattern, so greater climate related risks are more likely to occur. Carbon storage in forests – for instance in trees and soil, is an essential attribute in stabilising the carbon cycle. The carbon pool of forest is considered as precious for two reasons. Firstly, photosynthesis of trees and plants is a natural process to absorb carbon dioxide from the air. Secondly, burning down the trees is the same as release of stored carbon dioxide to the atmosphere. The escalating carbon dioxide level is less likely to be held back, forests become more vulnerable as a result of the vicious cycle of global warming.
Hong Kong has a humid subtropical climate, and self-igniting plant species can hardly be found. It is crystal clear that none of the 1,000 cases of hillfire reported annually are natural. Most of the fires are fuelled by the sparks from burning weeds and lighting incense while grave-sweeping. More than destruction of landscape and animals’ habitats, hillfires result in soil erosion that leads to land degradation and badlands. Also, reservoirs are more likely to be blocked by the loosened soil, depleting the capacity of freshwater storage. Tree-planting teams are sent by the government to restore the landscape, yet, a second's carelessness could ruin efforts in years. Restoration is the final fix, preventing the hazard is always the second thought.