Wheat futures are climbing after Ukraine's Black Sea ports came under renewed Russian fire, with three dry-cargo ships struck in recent days. Earlier Thursday, Ukraine attacked the Russian Black Sea port of Taman, a key gateway for grain shipments, while Russia hit vessels in and around Ukraine's Black Sea ports. Black Sea TurmoilThe UN has warned that Russia’s attacks on Black Sea ports are increasing risks to global food security. Last week, Bloomberg Agriculture Spot Index (BCOMAGSP) climbed to a three-year high on conflict fears across the Gulf area and worsening Black Sea conditions. The UN's Global Food Index has trended higher over the last 2.5 years.