As international leaders gather in Paris to mark the second anniversary of the climate change plan agreed in the French capital in 2015, Theresa May has announced millions of pounds of UK funding to help those worst affected.
Mrs May announced £140 million of new funding to help the world's poorest communities build resilience to extreme weather events caused by global warming.
And she said the UK will give an extra £15 million to help Caribbean island state Dominica recover from the devastation of Hurricane Maria in September, as well as a further £87 million for poor communities fighting against illegal logging.
Britain will demonstrate its commitment to clean growth by hosting a global Zero Emission Vehicle Summit in the autumn of 2018. And the UK is also joining Canada in leading the expansion of a drive to phase out the use of "unabated" coal burnt without use of carbon capture and storage technology.
Speaking ahead of her visit to Paris, Mrs May said: "Tackling climate change and mitigating its effects for the world's poorest are among the most critical challenges that we face. That is why I am joining other world leaders in Paris today for the One Planet Summit and committing to stand firmly with those on the front line of extreme weather and rising sea levels.
"And by redoubling our efforts to phase out coal, as well as build on our world-leading electric car production, we are showing we can cut emissions in a way that supports economic growth."
Also attending the summit hosted by French President Emmanuel Macron are expected to be world leaders including Jim Yong Kim, president of the World Bank, and Antonio Guterres, the United Nations secretary-general.
The UK funding for resilience will go to some of the communities disproportionately affected by climate change, whether through deforestation or vulnerability to natural disasters and climate extremes.
It is intended to offer help to an additional two million people with measures such as irrigation for better harvests, support in planting more resilient crops, improved forecasting and help to develop insurance schemes.