The theoretical physicists specializing in complex systems Mauro Bologna and Gerardo Aquino have come to the conclusion that global deforestation caused by human activities could trigger the irreversible collapse of human civilization within the next twenty or at most forty years.

Specifically, physicists believe that, at this rate, we will no longer have forests in about 100-200 years.
But clearly unrealistic to imagine that human society only begins to feel the effects of deforestation after even the last tree is felled, they write.
The collapse of human civilization would in fact occur much earlier, due to the increasing impact of deforestation on the support systems necessary for the survival of humans including the absorption of carbon dioxide, the production of oxygen, the conservation of the soil, the regulation of the water cycle, the for human and natural food chains and habitat for an unspecified number of species.
In the absence of these fundamental elements, it is highly unlikely to imagine the survival of many species, including ours, on Earth without [forests], the study notes.
The progressive deterioration of the environment due to deforestation would have a huge impact on human society.
As a result, human collapse would begin much earlier.
Bologna lecturer at the Department of Electronic Engineering of the University of Tarapac, Chile, and Aquino researcher at the Alan Turing Institute in London currently engaged in the construction of models of complex political, economic and cultural systems to predict conflicts.
In the past he has conducted research in the biological physics group of Imperial College, the Max Planck Institute of Complex Systems and the University of Surrey mathematical biology group.
Their study models the current rate of population growth and deforestation as variables of resource consumption, all with the aim of calculating the remaining possibilities for civilization to avoid collapse.
Before the development of human civilizations, the Earth was covered with 60 million square kilometers of forest.
As deforestation accelerated by humans' environmental footprint on the planet, the new study notes that less than 40 million square kilometers of forest remain today.
By comparing the current population growth rate with the deforestation rate, the authors found that statistically, the odds of surviving without facing catastrophic collapse are very low. The most optimistic scenario is that we have less than a 10 percent chance of avoiding it.
The authors write:
In conclusion, our model demonstrates that a collapse of the human population caused by resource depletion is the most probable scenario of dynamic evolution based on current parameters.We conclude from a statistical point of view that the probabilities that our civilization will outlive itself are less than 10. percent in the most optimistic scenario.
The calculations show that, maintaining the current rate of population growth and consumption of resources, especially forestry, we have a few decades left before an irreversible collapse of our civilization.
This verdict would therefore seem to indicate that there is more than 90 percent probability of a collapse of industrial society based on the impact of deforestation alone on the planet's carrying capacity and its ability to sustain human life.
We call this moment the tipping point, they explain, because if the deforestation rate is not altered before this moment, the human population will no longer be able to sustain itself and a disastrous collapse or even extinction will occur.
Faced with the prospect of collapse, and without changing our unsustainable levels of population growth and consumption, the only other avenue for survival would be unprecedented technological development.
In the study, the authors offer an interesting techno-utopian perspective: a Dyson sphere, a hypothetical megastructure around the sun that absorbs the bulk of its energy and sends it back to Earth.
The Dyson sphere is not to be taken literally, but for its energy value, Dr. Aquino told me.
The same amount of energy could be produced in any other way (with nuclear fusion, for example).
It may help to think of the Dyson sphere in the context of the Kardav scale, a measure proposed by Soviet astronomer Nikolai Kardav in 1964 to establish the level of technological advancement of a civilization based on the amount of energy it can accumulate.
The Kardav scale suggests that if a civilization can achieve technological advancement that makes the most of the energy of its star, this would allow it to go beyond the usual limits of resources.
The consumption of natural resources, especially forests, in competition with our technological level, wrote Aquino and Bologna.
As theoretical physicists, much of the paper addresses these problems on a theoretical, and partly hypothetical level of what a society would need to transcend resource constraints, and what would such a society look like?
A higher level of technology leads to population growth and increased consumption of forests but also to a more effective use of resources.
With a higher technological level we could ideally develop technical solutions to avoid / prevent the ecological collapse of our planet or, as a last resort, to rebuild civilization in an extra-terrestrial space.
Of course, the authors acknowledge that our engineering skills are currently insufficient to make such a powerful technology.
By widening the focus of the study for a moment, the authors speculate that this circumstance may explain why we have not yet been able to detect traces of intelligent alien life on other planets: the dynamics exemplified by this model suggest that intelligent civilizations tend to shrink into ash due to the depletion of their planet's resources before they can reach a technological level to become more advanced and resist these circumstances.
A deeper investigation of the study reveals further problems.
In particular, it is worth focusing on the model of interaction between humans and forests, which gives the most worrying results.
The reason this model is based on deterministic population growth parameters and deforestation projections are based on current conditions.
The assumption, therefore, that these rhythms and conditions will simply continue to remain around the same level.
In this type of exercise, the model is not designed to take probabilistic ifs into account: indeed, it demonstrates what would happen in a scenario of literal business as usual that takes current trends and applies them to the future.
The verdict, therefore, is very extreme: if we maintain the same rate of deforestation, population growth and resource consumption, collapse appears inevitable within the next two or at most four decades.
The good news is that this pessimistic scenario, although it reflects the very serious risks of the trajectory we are on, may not take into account the most recent data and expectations regarding these trends.
According to the 2020 State of the Worlds Forests, the report published by FAO, the UN Food and Agriculture Observatory, together with the Observatory on the Environment (UNEP), the global deforestation rate has been declining in recent decades.
From the 1990s to the period between 2010 and 2020, the net loss of forest areas decreased from 7.8 million hectares per year to 4.7 million hectares per year.
One of the reasons that despite the continuing deforestation, new forests are being created at the same time, both naturally and by deliberate planning.
But the deforestation rate also appears to have decreased in itself.
In the 1990s, the UN report indicated a deforestation rate of around 16 million hectares per year.
Between 2015 and 2020, it dropped to around 10 million (estimated) hectares per year.
Yet there is no need to be too optimistic.
In absolute terms, the UN report shows that the global forest area, however, decreased by 178 million hectares (!!!)
between 1990 and 2020.
Furthermore, we run the serious risk of reversing.
The most recent data produced by the World Institute of Resources's Global Forest Observatory confirms that the loss of primary forests in 2019 was 2.8 percent higher than the previous year, indicating that the rate of destruction is starting to rise again.
Similarly, population growth projections are likely to be lower than expected.
A new set of predictions published by The Lancet suggests that population growth rates could decline after mid-century due to declining fertility rates, contrary to past projections.
Unfortunately, the time frame required for these changes may be too long to substantially alter the predictions of the model shown in Scientific Reports.
As the authors point out, it is difficult to imagine, in the absence of a very strong collective effort, large changes to these parameters taking place in such a short time frame beyond the possibility of fluctuations around these trends.
But these slowdowns indicate that avoiding such dangerous exponential growth may be possible, especially by using a more active and focused approach.
Another way to avoid collapse, the authors speculate, a reform of civilization from the ground up.
What puts us on the current trajectory towards collapse is that the consumption of planetary resources may not be perceived as a deadly danger to human civilization because it is driven by the economy. Such an organized civilization favors the interest of its members who are less or at all concerned with the ecosystem that hosts them.
The most effective way to increase our chances of survival is to move from self-interest in the strict sense to an idea of collective care for each other, and for the ecosystems in which we find ourselves.
Illustration by Pamela Guest.

From Vice