Why are tropical forests important for everyone in the world?
Google Earth recently released a time-lapse video illustrating the destruction of forests in the last thirty years. It is painful to watch, but why do we feel this way? The answer to this question is so extensive and broad that it is hard to know where to begin, and this blog will certainly not be definitive. Everyone knows that deforestation is a bad thing. But when the trade-off is between chocolate or coffee, coconut, the minerals that make phones and computers work, a gold ring, a beef burger or, of course, the palm oil in our foods and cosmetics (all of which are grown or mined where tropical forest has been cleared)… a few fewer trees in some distant land doesn’t seem to matter so much. Nevertheless, it is important to know what we are losing when tropical forests are being permanently degraded or destroyed.
To be clear, I am going to focus on forests that are located in tropical climates. Forests in other regions are also important of course, but are less likely to have parts that are undisturbed and are much less rich in biodiversity. Tropical forests constitute 45% of all forests and are experiencing the fastest rates of deforestation. Why does this matter?
Carbon Capture and Storage
Forests are sometimes called the ‘lungs of the planet’ but that does not quite explain their function and importance properly. Through photosynthesis, trees do indeed take in carbon dioxide and release oxygen. Most importantly, however, trees take in carbon and use it to create their own biomass. Huge amounts of carbon is stored as part of plants’ biomass, forest litter, deadwood and in the soils. The FAO estimates that there is 296 Gt of carbon stored in the world’s forests, possibly double that in the atmosphere. Importantly, about half of this is in the soil. Not all forests and soils store carbon equally. The highest densities of sequestered carbon are in the forests of South America, and Western and Central Africa, storing about 120 tonnes of carbon per hectare in the living biomass alone.
Carbon dioxide is released back into the atmosphere when the sugars in the plant are metabolized by a plant or animal, the dead biomass decomposes, or a fire burns through the forest. If the average passenger vehicle releases about 4.6 metric tons of carbon dioxide a year, clearing just one hectare of forest in South America would be equivalent in emissions to driving 26.5 cars for a year. Whilst most natural forests take in more carbon then they release, human activity has accelerated the release of forests’ carbon store through cutting down trees, draining peat soils and burning fires to clear the land. As you can see below, between 1990 and 2020, on average Brazil has had the most carbon emissions from forest land whereas Russia has had the most carbon removal from forest land.
Biodiversity
Tropical forests are the ultimate habitat for all sorts of life. They are warm, wet, with lots of other species to interact with. They are thought to host half of the world’s species richness in just 6 to 7 percent of its land area. Additionally, tropical and subtropical forests contain ten hotspots with the greatest numbers of endemic plant and animal species (living only in one area) and the greatest number of threatened species. Researchers found 270 plant species per 0.1 ha in Colombia. This is before accounting for the unknown numbers of undiscovered plant and animal species we don’t know about!
Why is this important? One of the reasons is that plants from tropical rainforests are a key source of medicines for many kinds of health care systems, including Ayurvedic and traditional Chinese, as well as Western mainstream medicine. Reportedly, there are over 28,000 plant species being used for medicinal use. This includes the Madagascar Periwinkle, from which vinca alklaloids have been isolated, which are used to treat various cancers. Given how few plants have been tested for their medicinal qualities, medical research could be missing out on countless opportunities when species become extinct. Forests don’t just serve humans, of course. Biodiversity is important for all kinds of plants and animals, and the loss of key species in the food chain may have wide reaching effects that are hard to predict.
Supporting Livelihoods and Cultures
We are all forest dependent to some extent, but some more than others, and none more so than indigenous groups who rely on tropical forests for their livelihoods and whose identities are rooted in the forest landscape. On Indigenous People’s Day, Nemonte Nenquimo, president of the Waorani of Pastaza and a co-founder of the Ceibo Alliance, wrote a powerful letter in the The Guardian in which she said,
… for Indigenous peoples it is clear: the less you know about something, the less value it has to you, and the easier it is to destroy. And by easy, I mean: guiltlessly, remorselessly, foolishly, even righteously. And this is exactly what you are doing to us as Indigenous peoples, to our rainforest territories, and ultimately to our planet’s climate.
There is different knowledge and there are ways of knowing and living that are intimately tied up in the tropical forest landscape that deserve to be respected.
In addition to carbon capture, biodiversity and livelihoods, we could also talk about regulating climate conditions, preventing soil erosion, as well as many country specific benefits. Whether or not you live close enough to feel it, tropical forests are vital to us all.
