Researchers from the University of Cambridge, UK, created a world map showing where farmland should be located to minimise environmental impact and maximise production. This could eliminate freshwater use, increase biodiversity and capture large amounts of carbon.
The “new” world map includes large farming areas for all the major crops in the mid-western USA and below the Sahara desert, among others. In contrast, areas of current farmland in Europe would be restored to their natural habitat.
Although this assumes highly mechanised farm practices with the use of heavy machinery, it would still cut overall carbon impact by 71% by allowing some land to revert to its natural forest state. This is the equivalent of eliminating 20 years of CO2 emissions at our current rate. Land covered by forests is much more efficient at capturing CO2: not only do trees capture CO2 as they grow, but also the soil can trap more carbon than if it had crops in it.
This could dramatically reduce the risk of extinction for many species as chosen croplands revert to their natural state. The authors believe these lands would recover their original ability to trap CO2 and biodiversity levels within a few decades.
The new farmlands would take advantage of natural rainfall, totally eliminating the need for irrigation. Agriculture currently uses about 70% of global freshwater, but this causes drinking water shortages in many parts of the world.
To re-draw the world map, the authors used 25 major crops, including wheat, barley, and soybean, representing over 75% of all croplands globally. With this data, they then developed a mathematical model to look at all possible ways to distribute farmland across the globe to maintain production levels for each crop. From all the scenarios found by the model, the researchers picked the one with the lowest environmental impact.
“In many places, cropland has replaced natural habitat that contained a lot of carbon and biodiversity – and crops don’t even grow very well there. If we let these places regenerate and move production to better suited areas, we would see environmental benefits very quickly,” said Dr. Robert Beyer, formerly a researcher in the University of Cambridge’s Department of Zoology and first author of the study.
While the authors acknowledge that a complete relocation can’t be put into practice, this work still highlights places where croplands are very unproductive but have a great potential to be good spots for biodiversity and carbon storage.
Instead of a worldwide approach, a redistribution within national borders would still have massive benefits: reducing carbon impact by 59% and increasing biodiversity by 77%. Even if countries only relocated the worst 25% of croplands, it would still result in about half of the benefits compared to moving all croplands.
“It’s currently not realistic to implement this whole redesign. But even if we only relocated a fraction of the world’s cropland, focusing on the places that are least efficient for growing crops, the environmental benefits would be tremendous,” said Beyer.
The researchers acknowledge that relocating must be done with the support of the people it affects. This could involve, for example, set-aside schemes where farmers receive financial incentives to return part of their land to forest. The same incentives can also be used to encourage farmers to move to better locations.
Much of the world’s farmland is located in regions where they have a huge environmental footprint and represent a significant drain on water resources. Humans chose these locations for their proximity to settlements, but the researchers believe it is time to grow food in a better way.
(1) Beyer, R.M., Hua, F., Martin, P.A. et al. Relocating croplands could drastically reduce the environmental impacts of global food production. Commun Earth Environ 3, 49 (2022). https://doi.org/10.1038/s43247-022-00360-6