Maria van der Hoeven, executive director of the IEA, and Pope Francis. Credit: Maria van der Hoeven:Leon Neal/AFP/Getty Images, Pope:Franco Origlia/Getty Images

The Paris-based International Energy Agency (IEA) posted a special report on energy and climate change on 15 June that is aimed at helping policy-makers to take action at this December's climate meetings in Paris. The next day came the early leak of Pope Francis’s long-anticipated encyclical on climate change and the environment. Remarkably, the pontiff's letter draws squarely from the latest research: so much so that some of its science-influenced passages would not look out of place in an IEA report. Below, Nature picks out some choice paragraphs from both reports: can you tell who said what?