Image credit: © Victor Englebert

Hardly a day goes by that we don’t hear about climate change and the havoc it’s wreaking or anticipated to inflict in the future. We hear that climate change could have a significant impact on forests, for example, and that the Amazon rainforest could be reaching a tipping point from which it might not recover.

Climate change is one way of destroying forests (in some regions at least; other regions might actually become more suitable to tree growth with a warmer climate). But there’s another way of effectively and more immediately destroying forests – and that’s to cut them down.

The primary reason for cutting down forests is agricultural expansion, and the main driver of agricultural expansion is the growing human population.

In our mid-November mailing on the famine in Madagascar, we said that 80% of tropical deforestation was caused by agriculture, citing a 2012 article. Recently, someone wrote to us and informed us that our statistic was out of date and the actual figure was closer to 90%. Data collected between 2000 and 2018 in a “Remote Sensing Survey” conducted by the United Nations’ Food and Agricultural Organization (FAO), which published its findings in 2020, show that 89.9% of global deforestation is due to agricultural expansion, including the conversion of forest to cropland (about 50% of forest loss globally) or grassland for livestock grazing (about 40% globally). The remaining ~10% of global forest loss is due to other causes, primarily urban and infrastructure development, and mining.

Broken down by continents, agricultural expansion accounted for well over 90% of deforestation in Africa and South America (mostly for cropland in the former and livestock grazing in the latter) and approached 90% in Asia and Oceania. In North and Central America (combined), agricultural expansion was responsible for 70% of deforestation, while in Europe, “other drivers” caused close to 70% of the deforestation. Europe is the only global region where agricultural expansion is not the overwhelmingly major cause of forest loss.

The dots of human population growth, expansion of land put under cultivation, and deforestation are not difficult to connect. The human population increases by over 80 million each year (net births over deaths) and every one of those people, in addition to the ones already there, must be eating, or the population wouldn’t be increasing.

But strangely, those dots are not being connected – at least as far as preventing deforestation is concerned. In a speech to the 26th Climate Change Conference of the Parties (COP 26) in November, FAO Director-General Qu Dongyu did not include reducing and eventually reversing population growth as one of the “upscaling actions to turn the tide on deforestation.”

Instead, he optimistically asserted that increasing agri-food productivity to meet the demands of a growing human population and halting deforestation were not mutually exclusive; he touted combining the latest technological innovations with local expertise on the ground to find out where and why deforestation and degradation happen and where action is needed. If word salads by politicians and bureaucrats could be turned into actual food, world hunger would quickly become a thing of the past.

Environmentalists talk about the impact of the human footprint on Earth. But the size of that footprint is inextricably affected by the total number of feet and this is especially true when it comes to food. Human beings can do without a lot of material things, but food isn’t one of them. Every human being alive today, however malnourished or undernourished, is here because he or she is eating, and what we eat will affect how much land is needed to grow our food. While some land is suitable only for grazing and not for growing crops, all things being equal, a largely vegetarian diet requires less land than a diet that includes meat. But it seems unwise to pin our hopes on vegetarianism; no and low-meat diets are becoming more commonplace, but outside of India, there are few countries where vegans and vegetarians exceed 15% of the population, and in most cases the percentage is much lower. Furthermore, in addition to agricultural expansion, population growth also drives bushmeat hunting, which poses an additional threat to biodiversity.

Human population growth is the ultimate driver of almost all environmental problems and the ecological collapse being manifested in different ways and to different degrees all over the world. Instead of putting most of their energy into addressing one symptom of human population growth – notably climate change – it’s time for our leaders to overtly acknowledge human population growth, in and of itself, as an issue requiring urgent attention. The consequences of population growth (which Malthus referred to as “positive checks”) are often brutal: conflicts and wars driven by resource scarcity, malnutrition and famine, unemployment, disease and poor health, family violence, and human misery in general.

Fortunately, slowing and eventually reversing human population growth does not have to be brutal. Population growth can be contained by what Malthus called “preventive checks.” While “the chaste postponement of marriage” that he advocated is still an option, there are many more and less challenging options available today. Wherever accurate information about family planning and the benefits of smaller families has been provided along with affordable contraception, birth rates have fallen dramatically. The Overpopulation Project has a list of family planning success stories from all over the world, including Costa Rica, Indonesia, Iran, Rwanda, South Korea, Thailand, and Tunisia. Bangladesh is another example of a country that dramatically slowed population growth through ethical and culturally compatible programs.

These success stories show that where there is a political will, there is a way to move toward sustainable population levels.

When we talk about climate change, deforestation, food security, water shortages, and resources scarcity in general, let’s not forget the population angle! Otherwise, we will not see the “forest” of human overpopulation and overshoot for the many individual “trees” which are the symptoms of that problem.


Madeline Weld, Ph.D.

President, Population Institute Canada