The rewilding milestone Earth has already passed

One particularly striking example is the shrinkage of the global wool industry. Production has fallen by around 50% from its peak in 1990. Grazing lands in Australia, New Zealand and Argentina – countries that use to be amongst the largest wool producers – have declined by 25%. Large areas of pasture have returned to nature, some of which is actively protected and home to unique species. For example, the huge 70,000 hectare (173,000 acre) White Wells sheep farm in Australia is now the Charles Darwin Reserve, home to 700 species of plant and 230 animals. Another 70,000 hectare (173,000 acre) area in Argentina, previously the Chacabuco sheep ranch, is now a nature reserve and home to the rhea or ñandú, an uncommon bird related to ostriches and emus. There are many similar examples worldwide.

While the use of synthetic alternatives has taken pressure off land, they have come with other issues, particularly plastic pollution and an increased reliance on fossil fuels. There are solutions to these new problems however, such as landless biodegradable bio-plastics based on fungal mycelium or microbial processes, and they are beginning to scale up. Further, while agricultural land use has declined, not all of it has been replaced by natural forests; there has been a huge growth in plantation forestry for timber products worldwide, and plantation forests generally harbour much less biodiversity than natural forests.

Overall, the steady slowdown in agricultural land use is welcome. However, it’s not guaranteed to continue, nor is it fast enough to bring about the land use change we need to achieve our global climate or biodiversity goals. To keep global temperature rise below 2C, we will need to tap the huge potential of our natural ecosystems to suck carbon out of the atmosphere.

What will happen in the future? We think current trends are likely to continue, with more and more land previously used for agriculture being freed up across the world. But this process could also accelerate further due to a range of promising technologies and solutions which could produce transformational change to our food systems, reducing land used for food production even more. Some of these are close to being a commercial reality; others are still just ideas in research labs.

What we can expect

Based on historical trends and future forecasts, it is likely that crop yields will continue to increase globally on average. In 1961, we produced just over one tonne of grain per hectare (0.4 tonnes per acre). We now produce over four tonnes per hectare (1.6 tonnes per acre).