The single most damaging thing humanity has done to planet Earth is to commit the simple act of feeding ourselves.

Humans have essentially evicted nature from more than 40 percent of the habitable land on the planet, and taken it over for growing food.¹ We have chopped down or burned forests to convert them to farmland, throwing immense amounts of carbon dioxide, the primary greenhouse gas, into the air. At least a third of the excess CO₂ now in the atmosphere came, historically, from human changes to the land.²

And after all that damage, we are not really doing a very good job of feeding everyone. Global hunger declined slowly for several decades, but then jumped as a result of the pandemic, the Ukraine war and the resulting run-up in global grain prices. Crop failures, driven by the increase in heatwaves and other weather catastrophes, contributed to the price increases. We have lately turned the corner and are again making headway against hunger, but slowly.

Humanity confronts an urgent double imperative: to increase the supply of food for a global population expected to peak above 10 billion,³ and to save what is left of wild nature even as we do so. These are not two problems: they are a single, interlocking problem. In the same way that people now speak of an energy transition to guide the global push for cleaner energy, we believe the world also needs a land transition.

The principles of this land transition are straightforward in theory, but difficult in practice. Instead of destroying more forests, we need to go in the other direction: we need to improve our food system so much that we can begin withdrawing from agricultural land, letting some of it revert to wilderness. That implies using the rest of our farmland far more intelligently. The excesses, the waste, the pervasive inefficiencies, the overuse of chemicals in today’s food system — all need to be squeezed out.

Some 2.3 billion people faced moderate to severe food insecurity in 2024 — a small decline from the previous two years, but still up by more than 600 million people from a decade earlier. A more serious measure, chronic undernourishment, stands at 673 million people, more than 8 percent of the world’s population.⁴

Commodity prices recently hit levels associated with the great global food crises of the mid-1970s and the late 2000s, and have not abated by much. The effects of the high prices have been felt most acutely in poor countries, where more than half of a typical household’s budget can go towards buying food,⁵ but the food-price inflation of recent years has also roiled politics in even the richest countries, contributing to the public dissatisfaction that has put far-right populists into power.

Agriculture is itself a major cause of the global climate crisis, accounting for more than 20 percent of global emissions.⁶ Experts have long worried that the food system could fall victim to the very climate crisis it is helping to cause. Now, the climate situation appears to be contributing to the disruption in commodity markets. Certain highly visible crops — including high-grade coffee and the cocoa that is the main ingredient in chocolate — have seen wild price fluctuations as farmers were hit by weather disasters.

More than 150 winners of the Nobel Prize and the World Food Prize warned earlier this year that governments have failed to take control of the situation. Agricultural research budgets need to be increased, they said, to secure the future food supply, but are instead being cut. “We are not on track to meet future food needs,” the laureates wrote in an open letter. “Not even close.”⁷

Historically, high food prices have destabilised the governments of poor countries, or even caused them to fall. The current price run-up has not had such effects yet, perhaps because it came at a time of so many other disruptions, including the global pandemic. Yet the price gyrations may foretell worse to come as the climate deteriorates.

One way to meet future food needs in the face of a deteriorating climate would be to put more land under plough. Yet that would be exactly the wrong strategy, accelerating the destruction of nature and sending much of the world’s wildlife and plant life towards extinction.

A better approach would be to close the ‘yield gap,’ the mediocre per-hectare agricultural production that is commonplace in many middle- and lower-income countries, compared to the high yields that are achieved in rich countries. It has been clear for decades that these yields could be increased, if poor farmers were given access to some of the basic tools of modern agriculture, like fertilisers. But governments nominally dedicated to closing the gap have a mixed track record when it comes to delivering for their farmers, and the yield gap is closing only slowly. If farmers can grow more food on less land, the effect will be to free up marginal farmlands that can be returned to nature.

Restoring nature to disused farmlands is called ‘rewilding,’ and it is becoming a common strategy across many parts of the world. Immense stretches of forest land have been restored. Sometimes it happens by neglect; in the United States, for example, the farms of New England had become uneconomic by the early 20th century, and were abandoned. The regrowing forests of that region are pulling enormous quantities of carbon dioxide out of the air and turning it into leaves, wood and soil carbon. Many rewilding projects are more deliberate than that, however. The United Kingdom has seen successful efforts to restore beavers, storks, sea eagles and other wild animals to the landscape, a process that always starts with restoring habitat where they can live.

The virgin forests at risk of imminent destruction are mainly in the tropics. For decades, rich countries have recognised that they ought to pay less affluent tropical countries to encourage them to save those forests, which — as long as they are standing — help to absorb industrial emissions of carbon dioxide. The funds flowing to poor countries for this purpose typically amount to a few billion dollars a year, whereas the need, according to some estimates, may be as high as $470 billion per year.⁸ Towards the end of this report, we will discuss a proposal from Brazil that might help to get this effort back on track.

For all its success, the modern food system is wasteful. At least 30 percent of the food farmers grow is never eaten.⁹ In Western countries that tends to occur because consumers buy more than they need and throw it out when it spoils, or in restaurants, they may be served meals too large to eat. In poor countries, the waste tends to occur closer to the farm, often due to poor storage conditions or inadequate transport to market. The problem can be as simple as rats or insects infesting the grain.

Globally, dietary habits are also a major part of the problem. Beef and lamb are profoundly damaging to the environment, requiring far more land, food and water than other meats.¹⁰ Diets based as much as possible on plants are not only less environmentally costly but usually healthier, too. Governments have been afraid to touch this problem, refusing even to consider policy options like meat taxes. The bright spot is that many consumers around the world are shifting away from beef and towards chicken, which can be grown more efficiently than cows.

As countries get richer, overall meat demand is rising. That is a major reason for the continued destruction of tropical forests and savannahs: to turn the land into pastures for grazing or fields for the production of feed. In Brazil, for example, millions of hectares have been converted to soyabean farms, with 70 to 80 percent of the Brazilian crop shipped to China every year.¹¹ The Chinese, in turn, use soyabean meal to raise immense numbers of animals for slaughter — one producer there uses skyscraper-like buildings to raise more than a million hogs a year, many times the size of a ‘large’ hog farm in the United States.¹²

The preference for meat-eating means that much of the world’s agricultural land is used to grow feed for animals, not food for humans. The intensive cultivation of maize and other feed grains is a major reason for the heavy use of nitrogen fertilisers, which have to be synthesised in factories that use immense quantities of fossil gas. Nitrogen fertiliser is not used judiciously in much of the world; it is often over-used. Usage is considered somewhat excessive in the United States, with its gigantic maize crop, but the application rates are even higher in China and India.¹³

Some of this excess fertiliser turns into a gas and enters the atmosphere, adding to the overall problem of greenhouse gases. More of it washes down rivers into coastal estuaries. There, the excess nutrients cause harmful blooms of algae; when the algae die, their decomposition consumes most of the oxygen in the water, leading to ‘dead zones’ depleted of sea life. The dead zone near the mouth of the Mississippi River is sometimes the size of the state of New Jersey,¹⁴ and China also has large ones. Governments have been so hesitant about cracking down on excessive fertiliser use that virtually no progress is being made on this problem.

Western consumers are sometimes startled to learn that their consumption patterns can lead directly to the destruction of tropical forests. Much of the deforestation in Indonesia in recent decades — think of terrified young orangutans fleeing burning hellscapes — was carried out to grow palm oil for sale into Western markets. That ingredient is sometimes listed on labels for ice cream and lipstick as ‘palmitic acid,’ ‘palmate’ or ‘palmitate.' Under heavy international pressure, the Indonesian government has made headway in slowing the rate of forest loss.¹⁵

The hardest-fought battles over forest destruction, however, have been in Brazil. Deforestation hit a peak in Brazil in the early 2000s, then was brought down under the presidency of the liberal president Luiz Inácio Lula da Silva. It started to rise under the right-wing government of Jair Bolsonaro, but with Lula back in office since 2023, deliberate destruction of the forest appears to be falling again.¹⁶ Suppressing deforestation in Brazil has taken tremendous political courage, and activists, journalists and prosecutors have been murdered for their involvement in the cause.

The Amazon is not saved, however. The forest has been hit in recent years by intense droughts that may have been worsened by global warming. The droughts, in turn, set the stage for immense destruction of forest lands by fire. Last year’s fire losses nearly matched the high losses of 2016. For many years, computer models of the forest have been signalling the possibility that it could essentially collapse in an overheated world, giving way to grasslands that would be biologically much poorer.

The risk of human destruction has not ended, either. An estimated 13 percent of the Amazon has already been destroyed,¹⁷ and additional lands have been degraded. The mighty forest covers parts of nine countries, and suppression of deforestation in Brazil has pushed deforestation into neighbouring countries. How much of the Amazon can be salvaged over the coming decades remains an open question.