Tropical Deforestation: Why is it so dangerous and why should we care?
By: Fabio Cresto Aleína
At the end of April, the Brazilian National Indian Foundation (FUNAI) announced a U-turn on the policy they have been pursuing for decades, effectively making 9.8 million hectares of ancestral indigenous land in the Amazon forest accessible to land grabbing, mining, and deforestation. Besides the ethical implications of this new regulation, which can destroy the means of sustenance of previously uncontacted indigenous tribes and potentially expose them to the current pandemic, this new turn in the Brazilian policy can have huge repercussions for the whole world. Tropical forests like the Amazon are biodiversity hotspots as they harbor half of all Earth’s species, and therefore are considered a key ecosystem in the preservation of global terrestrial biodiversity. Without a strong plan to protect such ecosystems, we will have no means to prevent the extinction of countless endangered species. If we zoom out from the Amazon and take a look at the tropics as a whole, we can see that the situation is dire almost everywhere, as deforestation rates are plummeting worldwide and most of the tropical forests are, like the Amazon, under threat because of the increasing human pressure.
In the tropics, deforestation mainly occurs because of land use change, with large-scale monocultures replacing the original tropical forests and therefore causing irreversible losses in biodiversity and carbon stocks. Forests are among the most efficient terrestrial ecosystems in storing carbon, sequestering it from the atmosphere into the living tissues of plants, as well as in the dead wood, in the litter and in the soil. Besides the huge losses in biodiversity, by transforming forests into plantations, land use is effectively amplifying carbon emissions. But hold on, someone could object: monocultures are plants too, are they not accumulating carbon as well? Well, they are, and normally plants in agriculture are growing even faster than natural vegetation, but in the long term, they do not store any carbon as they are generally harvested after 10 to 20 years in the tropics, therefore returning most of the accumulated carbon to the atmosphere.
Natural forests, conversely, are able to store more carbon for longer timescale, and they are generally more resilient to climate extremes and diseases, as they evolved self-regulating and self-regenerating mechanisms that enabled them to survive for millennia before the arrival of humans. In other words, cutting forests both releases carbon dioxide to the atmosphere (in case trees are burned), and eliminates the carbon accumulation ability of the ecosystem. But the ecosystem services of forests (and tropical forests in particular) do not stop at their ability of accumulating and storing carbon, or at their role as biodiversity hotspots. Tropical forests are in fact also involved in the regulation of water supply, a function which is often neglected. By stabilizing the soil and therefore reducing the risk of landslides and by reducing soil erosion, as well as by enhancing water recycling through evapotranspiration, they play a fundamental role in reducing the water security risk.
Evapotranspiration is basically the pump-like process that transfers water from the soil to the atmosphere, therefore increasing air humidity and the water available for precipitation. This is particularly true in the Amazon, where up to one third of the local rainfall originates within the Amazon basin. An increase in deforestation will definitely decrease this contribution, thatdoes not stop at the Amazon basin: actually, all countries in South America (except from Chile) and some of Central and North America are benefitting from the moisture coming from the Amazon. Recent studies also showed how increases in deforestation rates can push this ecosystem towards a so-called “tipping point”, after which most of the Amazon will become a drier savanna-like ecosystem in less than 50 years, with catastrophic consequences worldwide.
Since the 2010 COP-10 conference in Nagoya, Japan, Guatemala has been recognized as one of the 20 “megadiverse” countries, and it owes this definition also to the abundance of its forests. In a recent study by Bronson Griscom and colleagues, Guatemala was identified among the first 40 tropical countries in which nature-based solutions to climate change are the most cost-effective in terms of sequestered CO2 equivalent per year. In particular, Griscom and colleagues showed that if we account for the total potential of nature-based solutions, they could cover over 100% of the total current greenhouse gas emissions of the country. In the case of Guatemala, the most important cost-effective nature-based solution for climate change are precisely the protection of the existing forests, and the restoration of previously forested land. Of course, a general global transition to a decarbonized economy is fundamental in order to reach the goals of the Paris Agreements, but science is showing us that countries like Guatemala already possess the natural potential to overcome the global challenge of reducing carbon emissions. It is also clear that to realize the potential highlighted in these scientific studies, the governments of tropical countries such as Guatemala will have to take immediate and difficult measures in order to combine a comprehensive plan for conservation and renaturation of the local ecosystems with the rural socio-economic development.
Avoiding deforestation and therefore limiting the expansion of croplands can potentially cripple the development of the agricultural sector. In policy science, this is called a “super-wicked problem”, which is a combination of complex problems, that defy any simple solution and can only be learned about as they are being addressed. The capacity to fight climate change depends also on the development of rural communities. However, some activities leading to such development, like deforestation for agriculture, can enhance climate change and its impacts; and unfortunately, this is one of the reasons why deforestation rates are not slowing down in Guatemala. Global Forest Watch reported that in the period 2000-2018 alone, Guatemala lost over 20% of its most forested areas (that is, areas with a forest cover larger than 75%), with a total tree cover loss of 35% in the same period of time. These numbers are huge, with the districts of Petén, Alta Verapaz, and Izabal leading the not-enviable ranking of the areas with the largest losses since 2000.
The solution to this super-wicked problem probably lies within a profound change of our means of production and the choice of a more sustainable and conscious agriculture, a choice that has to be shared by the politicians, by the farmers, but also first and foremost by the voters and the consumers. We all have the responsibility of driving the change. Of course, larger countries like Brazil and Indonesia are often on the front pages of the world’s news because of the sheer amount of hectares lost every year to unsustainable agriculture (mainly related to the meat industry) and other commercial activities, but we cannot forget what is happening right at our doorsteps, even now, while facing one of the most dramatic global health and economic crises in history.
References and further readings:
Griscom et al., National mitigation potential from natural climate solutions in the tropics, Phil. Trans. R. Soc. B (2019)
Levin et al., Overcoming the tragedy of super wicked problems: constraining our future selves to ameliorate global climate change, Policy Sciences (2012)
Lovejoy and Nobre, Amazon tipping point: Last chance for action, Science Advances (2019)
Spracklen et al., Observations of increased tropical rainfall preceded by air passage over forests, Nature (2012)
Staal et al., Forest-rainfall cascades buffer against drought across the Amazon, Nature (2018)
Torres and Brandford, “Brazil opens 38,000 square miles of indigenous lands to outsiders”, Mongabay (2020)
Mongabay, “Deforestation statistics for Guatemala”