Environment Climate change is already having a big impact on crop yields, and the subsequent financial losses will continue to rise as the world keeps warming The economies of countries where many people work in farming will be hit the hardest Global warming-fuelled heat and drought is already hitting yields of maize, wheat and soybeans to the tune of $20 billion a year, a study has estimated. This could rise eightfold, to more than $160 billion by 2100, unless we slash emissions.