Why does the World need Grain to be Shipped from Ukraine?

Resume Exports of Grain through the Black Sea

Ukraine and Russia have signed “mirror” deals which will allow Kyiv to resume exports of grain through the Black Sea.
 
The agreement will allow millions of tonnes of grain, currently trapped in Ukraine by the war, to be exported.
 
The world shortage of Ukrainian grain since Russia’s 24 February invasion has left millions at risk of hunger.
 
Credit to : BBC News