As Russia continues its invasion of Ukraine, gas prices remain high around the world. Europe is dependent on Russia for about 40% of its natural gas supplies, and despite the expansion of renewable energy over the past two decades, that dependency is increasing as countries shift to gas from dirtier coal. Putin’s attack on Ukraine has put this reliance into sharp focus as Europe considers how to respond. Madeleine Finlay speaks to our environment correspondent Fiona Harvey about how Putin has weaponised Russia’s fossil fuels, and how Europe could reshape its energy supplies for the future. Help support our independent journalism at theguardian.com/sciencepod