Once a luscious, vibrant green forest bursting with life is now a desolate grassland where dry brown grass wilts in the dusty heat. Rain is becoming rarer, and the formerly rich soils are parched. The steaming jungle is a thing of the past
here.
In the heart of South America lies the Amazon rainforest, the largest forest on our planet, spanning 5.5 billion square kilometres. It covers more land than all the other rainforests combined. The Amazon is an effective carbon sponge,
absorbing an impressive half a billion tons of CO2 per day, whilst supporting a rich forest ecosystem containing over 40,000 plant species and 2.5 million insect species.
The forest is known as the ‘lungs of the earth’ due to a large amount of oxygen released by the trees as they respire. In addition, evapotranspiration pumps an astonishing 20 billion tons of water vapour into the atmosphere every day. This
condenses into clouds which move west towards the Andes, where it falls as rain and drains back into the amazon basin, feeding the river, forest, and wetlands of the delta.
This movement of airborne water is commonly known as a ‘flying river,’ and is the major source of water and life for the entire Amazon rainforest, which covers a substantial area of the South American continent.
The importance of this hydrological cycle has been vastly underestimated, and the consequences are beginning to show. Deforestation of the Amazon is known to be a terrible practice due to its detrimental impacts on biodiversity, native
tribes, and the ability of the forest to act as a carbon dioxide sink.
‘The loss of large areas of rainforest is leading to a decrease in evapotranspiration, leading to an overall decrease in rainfall.’
However, it has recently been concluded that the loss of large areas of rainforests is leading to a decrease in evapotranspiration, leading to an overall decrease in rainfall across the region.
Tree felling for timber is a major source of deforestation, however, in recent decades clearing for agricultural expansion has been rising rapidly as the demand for beef escalates. Meat consumption has more than doubled in the last 50
years, putting pressure on farms to increase production and meet demands. Farmers often use the infamous slash-and-burn technique, setting fire to patches of forest to release land for cattle or soybean production.
This is particularly damaging, as large amounts of carbon dioxide are released into the atmosphere, whilst also reducing the carbon-sponge effect of the forest, decreasing natural habitat, and reducing the amount of water vapour produced.
The resulting smoke also adds millions of particles into the atmosphere, which prevents rainfall by drying the clouds. This prolongs the dry season, meaning fires are more likely to spread, exacerbating the loss of vegetation and wildlife
as the fire-protecting humidity of the forest is lost.
Amazon trees have not been exposed to fires naturally and therefore have not evolved any fire resistance like the trees of the Cerrado. In the short space of only two months without rain, the forest becomes dry enough for the fire to spread
rapidly and turn huge areas into smoke and ash. Deforested areas are particularly fire-prone, and will go up in a blaze if slash-and-burn fires are started nearby.
With the loss of trees, Amazon droughts are becoming more common, a huge worry for both humans and wildlife. Water is the main input for agriculture—without it, there would be no vegetation, no pollinators, and therefore no food. Over time,
increasingly prolonged droughts, escalated by climate change, are intensifying this deforestation-drought feedback loop, converting large portions of an already struggling rainforest into dry savannah.
‘With the loss of trees, Amazon droughts are becoming more common, a huge worry for both humans and wildlife.’
Amazon species are not adapted to live in a dry environment; poison dart frogs need water to pool in leaves to raise their tadpoles in, tamarins and marmosets rely on juicy, succulent leaves and fruits to gain moisture, and giant river
otters hunt in the rivers and lakes, which are slowly shrinking.
The droughts also inhibit the ability of the forest to regenerate and recover after fires, which will further compromise the net amount of carbon dioxide the Amazon is able to absorb. This is of huge concern, with scientists warning that if
climate change and global warming are to be combatted, deforestation of the Amazon must be halted in order to conserve this precious carbon sink.
This begins with protected areas, national parks, and government laws that inhibit logging and burning of the forest for commercial use. However, monitoring such a vast area is difficult; illegal logging, burning and ‘agricultural sprawl’
are rampant across much of Brazil and Venezuela, and often cattle ranchers do not realise the full extent of the damage they are doing or are financially motivated without considering the long-term consequences.
Biological ‘hotspots’ require increased protection and sustainable land management to conserve the array of essential species which reside there. Law enforcement is also a major requirement in order to maintain the principles of the
protected areas, preventing poaching, logging, or other illegal activities from damaging these areas of the forest.
Regeneration projects, including tree planting over previously deforested areas, can aid restoration, alongside efficient re-use of logged or wasteland areas.
Despite the seemingly endless sprawl of lush green, steaming, thriving forest, the Amazon is clearly struggling to cope with the increasing pressures and demands humans are putting on it, both directly and indirectly. The rainforest is one
of the planet’s most important and effective tools to tackle the global climate crisis, and it needs strict protection now more than ever if it is to survive.
Staal A., Flores B., and Aguiar A. (2022). Feedback between drought and deforestation in the Amazon. Environmental Research Letters. Volume 15, Issue 4.