Christopher Bonasia
The Advocate

A recent study improves projections for future crop yield by trying to estimate the financial trade-offs that influence farmers’ decisions about issues related to climate adaptation.

The results show that yields of six major crops — maize, soybean, wheat, rice, sorghum and cassava — could decline by an overall average of 25 per cent worldwide by the end of this century as adaptation efforts are held back by high costs to farmers and limited access to resources. 

Impacts from climate change will be felt worldwide, but with varying severity across crops and regions. Of the six crops, all will have lower yields by 2100 than they do today except for rice, where losses in some regions will be offset by increases where the crop benefits from new temperature and weather patterns.

Regionally, wealthy breadbasket regions like Canada and the rest of North America show some of the most severe losses, in part because limited climate impacts in those areas to date have not motivated farmers to adapt like those in other regions that are already experiencing severe changes. Figures included in the study show that in Quebec, yields for wheat, maize and soybeans are all expected to decline, though sorghum yields could increase.

While “wealthy-but-low-adaption regions” show the highest losses, the impacts to food security will be more severely felt elsewhere, and it will be poorer regions that are hardest hit by the loss of food access and greater price volatility.

Past research has estimated how climate change would affect crop yields in projections where farmers adapted either entirely or not at all. But this study factored in the financial trade-offs behind real-world management decisions, with estimates suggesting that adaptation rates would be influenced by how adaptation costs compare with income losses from climate impacts.

“Adaptation is costly to farmers,” said Andrew Hultgren, an environmental economist at the University of Illinois Urbana-Champaign and lead author of the study. “It is not free.”

While the researchers couldn’t collect data on all the myriad ways farmers can or will adapt to climate change, they were able to detect adaptation by identifying where losses occur alongside severe weather events.

For example, significant losses linked to severe heat in regions where high temperature shocks are rare indicate that adaptation had not occurred; at the same time, yields being maintained in regions that are used to high temperatures showed that farmers had taken adaptive measures, like by switching to heat-tolerant or early maturing varieties.

But as Hultgren and his colleagues note, the new varieties often produce lower yields per acre, and other adaptive measures to different climate impacts have their own financial burdens. These costs can mean that it may be more profitable for farmers to not adapt, and so they are less likely to.

Notably, the researchers were not able to account for future advances in technological, nor for farmers changing crops to better accommodate altered growing conditions. But the study points to a gap between what is possible and what is happening, as better access to resources or providing financial support for climate adaptation could change the balance of the trade off, making it more likely that farmers will choose to adapt.

 “The results indicate a scale of innovation, cropland expansion or further adaptation that might be necessary to ensure food security in a changing climate,” the authors write.

Unfortunately, that support has been insufficient in Canada, as programs aimed at supporting farmer adaptation — like the On-Farm Climate Action Fund — remain over-enrolled and underfunded.

Similarly, profit margins for farmers are at a historic low point and are likely to be weakened by increasing consolidation in the agri-business sector, such as by the recently finalized Bunge-Viterra merger that Canada’s competition watchdog said would have “substantial anti-competitive effects” before the federal government gave it the greenlight back in January.

While the study doesn’t answer whether adaptation can sustain current yields against climate change, it does suggest that keeping farmer profits low and failing to provide sufficient climate adaptation support will hold back efforts to limit losses.