system
Given the following post, respond as if you're commenting on Reddit:
human
How will Ukraine war impact grain production? Will this lead to higher prices for food and what effect will this have on poorer countries?
gpt
Ukraine and Russia both are large fertilizer exporters, as well as large exporters of grains. Nitrogen fertilizer, which is largely used for corn and wheat, is produced in an energy intensive process, usually with natural gas. Hence, the spike in European natural gas prices has shut down some nitrogen fertilizer production in Europe. Therefore, there is a *significant* global shortage of fertilizer, particularly nitrogen based fertilizers given Russia sanctions, Ukraine production offline, and high natural gas prices in Europe. 

This means fertilizer is very expense and suggests that the global wheat and corn crop will be smaller as farmers either (1) cannot afford to pay up front for fertilizer or (2) as they try and substitute with less effective fertilizers. This means higher grain prices in 2023. 

Given the existing sanctions on Russia and the events in Ukraine, there is also a massive disruption of the current crop outlook. Therefore, prices for corn and wheat have increased significantly. This means food prices increase globally and there is a significant chance of famine and social unrest.