Britain's Cop26 president Alok Sharma visited Russia on Tuesday to urge one of the world's largest emitters of carbon dioxide to commit to net zero by 2050, praising Vladimir Putin's support for tackling climate change.
Britain, which hosts the 26th United Nations Climate Change Conference of the Parties, or Cop26, in Glasgow from October 31 to November 12, is seeking major power support for more radical plans to fight climate change.
"I welcome the support President Putin has shown for international co-operation on tackling climate change, and look forward to constructive discussions here in Moscow," Mr Sharma said.
"Russia is an essential player in the fight against climate change."
Scientists, activists and world leaders say human activity – primarily the release of carbon dioxide and other gases into the atmosphere – is heating up the planet in a way that will lead to devastating changes to the weather and, in turn, life as we know it.
Scientists say there has been about 1°C of global warming since pre-industrial levels due to human activity.
Britain wants countries to be more ambitious to achieve net-zero emissions by 2050 and thereby limit the average temperature rise to 1.5°C this century, as agreed under the 2015 Paris Agreement.
China is the world's largest fossil fuel carbon dioxide emitter, followed by the US, India, the EU plus Britain, and then Russia, Emissions Database for Global Atmospheric Research figures show.
Some sceptics say the models used in climate science are inconclusive and fear the regulation required to meet some of the targets will hurt economic growth.
But climate activists say world governments are not going fast or far enough to combat climate change and say many political leaders are making grand pledges without giving a clear idea of how to achieve their stated ambitions.
"By capitalising on the benefits offered by shifting to a cleaner, greener economy, Russia has an opportunity to show real leadership as the world continues on its journey to net-zero emissions," Mr Sharma said.