A study looking ahead to 2070 found that climate change was occurring thousands of times faster than the ability of crops to adapt.
Wheat, rice, maize, rye, barley, and sorghum are all edible grasses that yield nutritious grains. In many parts of the world and throughout history, wheat or rice famines have led to widespread starvation.
The research, published in the Royal Society journal Biology Letters, looked at the ability of 236 grass species to adapt to new climatic niches — the local environments on which they depend for survival.
Faced with rapid climate change, species wedded to a particular niche can survive if they move to another region where conditions are more suitable, or evolve to fit in with their altered surroundings.
The scientists found that the predicted rate of climate change was typically 5,000 times faster than the estimated speed at which grasses could adapt to new niches. Moving to more favourable geographical locations was not an option for a lot of grass species because of the limits to their seed dispersal and obstacles such as mountain ranges or human settlements.
While the research cannot predict what might happen to world food supplies as a result, the authors warn of “troubling implications”.