According to researchers at the Harvard T.H. Chan School of Public Health, if the present rates of carbon dioxide emissions do not stop, people in around 18 countries worldwide may face a loss of around 5% of the protein they obtain from their diet by 2015. This is due to the reduction in the nutrient values of crops such as rice, wheat and other staples. This would put an additional 150 million people at risk of dietary protein deficiency. This is the first study that actually quantifies the actual dietary health risk posed by greenhouse gas emissions.