One of the surprising things about increases in carbon dioxide in the atmosphere is that higher CO2 levels appear to lead to a decrease in nutrients in the crops. That counters the argument that more CO2 has a fertilizing effect on plants which is often used to minimize the harm from rising levels of greenhouse gases. Studies have shown that the higher CO2 levels disrupt the plants’ internal chemistry and so affects the amount of nutrients and protein they can store.
This is not so important for countries like the US with plenty of food available, but could cause an increase in famines in countries with marginal food supplies that depend heavily on crop productivity to feed their people. You can read more here.
