G20 leaders have committed to reaching net zero "by or around mid-century" ahead of the COP26 climate conference.
Leaders of the world's 20 largest economies have also agreed to end public financing for coal-fired power generation abroad, but set no target for phasing out coal domestically.
The lack of agreement over the domestic issue relates directly to top carbon polluters China and India - and represents a failure by leaders to agree on a key issue.
Wrapping up two days of talks in Rome ahead of the global COP26 climate summit, the group of 20 had been looking to find common ground and definitive commitments on how to reduce emissions while helping poorer countries deal with the impact of climate change.
The 20 members, which include the UK, the US, China, India, Brazil, Russia and the EU, represent more than three-quarters of the world's greenhouse gas emissions.
The nations are essential to pushing forward commitments to ensuring global temperatures do not reach 1.5C above pre-industrial levels - the main aim of COP26, which is being hosted by the UK.