Diplomatic tensions over global warming spilled over into the G20 summit negotiations in Brazil this week, with sources saying the 20 major economies reached a fragile consensus on climate finance that had eluded U.N. talks in Azerbaijan.

Heads of state arrived in Rio de Janeiro on Sunday for the G20 summit and will spend Monday and Tuesday addressing issues from poverty and hunger to the reform of global institutions. The talks must now also grapple with how to address escalating violence in Ukraine after a deadly Russian airstrike on Sunday.

Still, the ongoing U.N. climate talks have thrown a spotlight on their efforts to tackle global warming.