Climate change to convert wilderness to farmland

Researchers at the University of Exeter have been attempting to find out how the world’s agricultural landscape might change over the next 40 years. By pulling together information on seventeen hundred crops from a database created by the Food and Agricultural Organization, they predict that, as global temperatures rise, wilderness areas closer to the Earth’s poles will become suitable for growing crops. At the same time, current agricultural areas will become less productive. As a consequence, farming may have to move, placing valuable wilderness ecosystems at risk. The study’s lead author, Alexandra Gardner, has been telling me about the research...

Alexandra - We wanted to look at what will climate change mean for agriculture and how might it change where we're able to grow crops? And we were particularly interested in high latitude areas currently classified as wilderness, so they're untouched by humans. These are really important areas for global biodiversity. They've got huge cultural value and they also have huge value as carbon stores. Are these areas going to be under threat from changes to agriculture?

Chris - So in order to feed a growing population, and an ever hungry world, because some areas, because of climate change, are going to be less good at growing crops, we're going to have to exploit areas that at the moment we regard as pristine wilderness?

Alexandra - Yeah, exactly. We've got a growing population we need to feed, so we need more food, but potentially on less land if some areas are becoming less suitable for growing crops. So we might be looking to areas where crops currently aren't grown and considering their conversion to agriculture.

Chris - How does one go about doing a study like that? How did you approach it?

Alexandra - We used a model called Ecocrop. Essentially, it looks at what the crop needs to grow and considers whether the temperature and the amount of rainfall that falls in the area over that season is going to be sufficient to allow it to grow. It was nearly 2000 crops. We modelled the climate suitability globally, 2008 to 2019, and then we made projections into the future and looked at, under two different climate scenarios, what might happen in terms of crop suitability for those crops. So we've just looked at climate, we've just looked at temperature and precipitation, how those are going to change and whether that will make it an area more suitable or less suitable for a crop.

Chris - And what picture emerges?

Alexandra - What we've seen globally is that large areas of land that are currently suitable for crops will no longer be suitable for crops in the future, or fewer crops will be able to be grown in those areas in the future. Whereas some places where cold temperatures currently limit crop reduction, they're going to become suitable for growing crops in the future.

Chris - Does this mean then that we're basically going to move farming from where it currently is to places that look much more promising just to sustain output and possibly augment output? Because we do have more people, we anticipate more people as we go into the future, and we've got to feed them.

Alexandra - That is the threat that we wanted to highlight. If we don't increase production or maintain production in some places on the land that is currently agricultural land, we will have to look elsewhere to meet the needs of a growing population.

Chris - Does your work give you any insight into how much new land we might have to open up and therefore how much wilderness might be under threat under these sorts of situations?

Alexandra - The area of land that becomes newly suitable for agriculture in the future, so that is an area where at present no crops can be grown but in the future at least one, possibly more crops, could be suitable to grow. This area is equivalent to 7% of the total wilderness areas. So 7% of wilderness becomes newly suitable for agriculture in the future.

Chris - So that means, given our track record for when an opportunity exists, we tend to find people exploiting it, up to 7% of the world's wilderness could be at risk?

Alexandra - Yes, if all of the areas that become newly suitable for agriculture in wilderness areas get converted to farmland, then up to 7% of total wilderness could be lost.

Chris - How bad did you assume climate change was going to have to get in order for the effects in your simulations to play out and therefore is it potentially preventable from that standpoint?

Alexandra - We looked at two scenarios of climate change, an intermediate scenario where we are able to cut our emissions of greenhouse gases, but still it results in a certain level of warming. And then we looked at a high emission scenario whereby essentially we do nothing, greenhouse gas emissions continue to rise and it's kind of the worst case scenario. Even with that intermediate scenario, there's still a lot of the wilderness at risk from being converted to agriculture, really just underscoring the fact that we need to do as much as we can to reduce those greenhouse gas emissions.