Russia is the world’s largest gas exporter, so major geopolitical changes throw the future a major portion of global gas supply into uncertainty. As things unfold, the gas market is moving in response to perceived risks of the war.
Russia could end up constraining or turning off its gas, which would mean remaining gas would become a much rarer, pricier commodity. Other countries could also decide to stop buying gas from Russia, which would also push prices higher as they’d all need to source gas elsewhere – putting a massively higher demand on a much smaller supply.
Europe is also buying up loads of gas right now to ensure it is well stocked for next Winter to reduce future reliance on Russia. Finally, Nord Stream 2, a new pipeline from Russia that would’ve increased supply significantly, now seems likely to be cancelled.