Why it might be better to mine the world's rainforests than farm them

As if the world’s rainforests didn’t have enough problems to contend with, even the transition to zero-carbon power is threatening to level them.
 

Industrial mining ate up 3,265 square kilometers (1,260 square miles) of tropical forest between 2002 and 2019, according to a recent study in the Proceedings of the National Academy of Sciences. Some 80% of that total happened in just four countries: Indonesia, Brazil, Ghana and Suriname.

With the COP27 climate conference in the Egyptian resort of Sharm El Sheikh next week expected to increase the focus on the climate needs of developing countries, that’s raised concerns that there isn’t enough land to manage a shift away from fossil fuels. Much of the world’s reserves of nickel, an essential metal for making electric-vehicle batteries, lie under the rainforests of Southeast Asia. Some 6,732 sq km of Indonesian forest has been granted to nickel mining concessions, a coalition of environmental groups wrote in a July letter to Tesla Inc.

An “honest and comprehensive evaluation of the entire life cycle of clean energy” cars would show a “negative societal and environmental impact” on land, Michael Heberling, an academic at Michigan’s Baker College, noted this year.

Mining certainly involves destruction of the land that surrounds it. Even where minerals are extracted from underground rather than surface mines, the tailings, processing facilities and transport infrastructure that surround them consume many hectares of countryside.

Still, the challenges of preserving the world’s ecosystems are so vast that we risk looking only at one small part of the elephant, rather than the whole beast. Almost every economic activity carries some sort of environmental cost. The question isn’t about finding activities that are cost-free, but identifying the ones that maximize the associated social and economic benefits.

At the outset, it’s worth considering that the sheer amounts of commodities that we use each year vary greatly: about 8.2 billion tons of coal and 4.2 billion tons of oil; 1.2 billion tons of corn and 780 million tons of wheat; 25 million tons of copper and 2.7 million tons of nickel; 3,000 tons of gold and 180 tons of platinum.

That doesn’t give the whole story, though. Nickel ores contain about a thousand times more metal per ton than gold ores, so the far smaller output of the gold industry results in a roughly similar volume of waste rock. Then there’s the question of surface disturbance: commodities extracted from open-cut mines such as iron ore have a far bigger footprint than those like platinum that are mostly mined from deep underground. Oil and gas tapped from the ocean floor don’t take up a single hectare of land, except for what’s used for onshore transport and processing.

Looked at in terms of land intensity — the number of hectares needed to supply humanity’s needs — it’s clear that minerals are still a highly efficient use of space. All the world’s mines cover just 101,583 square kilometers, according to a study this year based on satellite observations — a smaller area than we use to grow oats, and equivalent to less than 0.2% of the world’s agricultural land.

Another consideration is how often the commodity gets re-used. The 50kg of nickel in an electric car battery will get used again and again over the tens of thousands of kilometers the vehicle is driven, and then may well be recycled for other uses when the vehicle is scrapped. The 50 liters of gasoline in your fuel tank, on the other hand, will need to be refilled several thousand times before the car is taken to the junkyard. Farmland, for all the vast areas that it consumes, can produce the same volumes year after year, even increasing over time with improvements in agricultural yields. 

Energy is an important and related consideration. If your electric car is charged up with power produced by burning coal, it’s likely to have a far more substantial land footprint than with electricity from nuclear, wind or gas — both because coal is profligate in terms of its demands for land, and because its supplies must be constantly renewed by digging yet more coal. Solar power, for all its advantages in terms of carbon emissions, also chews up a great deal of land.

A final consideration is to think about the cost of land use as well as its benefits. All land is not created equal. Some 60% of the world’s carbon biomass is stored in forests, with another 22% in grasslands and savannah. Keeping that carbon locked up in living tissues rather than venting it into the atmosphere is a burden that falls particularly hard on lower-income tropical countries, which have some of the largest reserves of forest and some of the greatest needs to consume land as an input into economic growth.

That’s where the rest of the world has a part to play. Economic development requires not just land, but labor, capital, and productivity improvements. Most emerging countries have no shortage of labor, but the capital required to develop land efficiently and drive their economies up the productivity value chain is far too scarce. Pledges that rich nations made a decade ago to provide $100 billion in annual investments to the rest of the world to decarbonize and adapt to the effects of climate change have still not been met.

If wealthy countries want the tropical forest lands that have already been cleared to be used more efficiently — and, where possible, returned to their natural state — then they’re going to need more, not less capital-intensive activity. Mining isn’t devoid of environmental impacts. But it’s a lot better than most of the alternatives.