With leaders from the world's biggest economies converging on Rio de Janeiro for a two-day G20 summit starting Monday, the usually relaxed seaside city is under a tight security blanket.

Heads of state arriving in Rio de Janeiro on Sunday for the G20 summit will spend Monday and Tuesday addressing issues from poverty and hunger to the reform of global institutions. Still, the ongoing U.N. climate talks have thrown a spotlight on their efforts to tackle global warming.

As Brazil gears up to host the G20 leaders summit, here are 5 things that will be at the top of the South American nation’s agenda