A former climate chief of the World Bank has been appointed to lead the UK’s efforts to forge a global coalition on climate action, the Guardian can reveal. Rachel Kyte, who previously served as special representative for the UN and a vice-president of the World Bank, will take up the role of climate envoy to lead the UK’s return to the front ranks of global climate diplomacy. Her role will be vital to the pledge made last week by David Lammy, the foreign secretary, that the UK would play a central role in tackling the climate and nature crises, in contrast with the previous government, whom he described as “climate dinosaurs”. The envoy role was axed by Rishi Sunak, to the anger of campaigners and dismay of foreign governments and allies. Sunak also snubbed international climate meetings. Kyte, a veteran of international climate summits, and most recently a professor at Oxford’s Blavatnik school of government, is widely respected among developed and developing country governments. She worked with many of them during her stint as chief executive of the Sustainable Energy for All initiative. Kyte told the Guardian: “This government is committed to reconnecting the UK to the world with climate action as a priority. And the world is being shaped politically and economically by climate change. This provides an opportunity to use international action to help deliver on the UK’s energy mission. And it provides challenges, not least in mobilising the financing to protect people and drive greener growth. There is no time like now for the UK to help drive action and I am excited to play my part in this new role.” Lammy and Ed Miliband, secretary of state for energy and net zero, will announce the appointment on Wednesday at New York climate week, where they are hosting an event on building a global clean power alliance. Miliband will hold discussions with other governments on the need for vastly increased pledges of climate finance to the developing world. Poor countries want assurances that they will receive at least $1tn a year in assistance to help them cut greenhouse gas emissions and cope with the impacts of climate breakdown. Climate finance will be the main topic of what are expected to be fraught discussions at the next UN climate summit, Cop29, in Azerbaijan. Miliband will lead the UK’s negotiations himself, in contrast with the previous government, in which it was left to junior ministers. The diplomatic charm offensive has already begun, as Miliband welcomed the president of Cop29, Mukhtar Babayev, to London in July, and in August made an extensive trip to Brazil, which is the current president of the G20 group and host of next year’s Cop30 climate summit. Lammy will also, with environment secretary Steve Reed, appoint a nature envoy for the first time, to push for global action on protecting the natural environment, as the Guardian revealed last week. That appointment is not expected until next month. Kyte, whose official title will be UK special representative for climate, will coordinate the UK’s relations with other donor countries, as well as forging alliances with the poor world, and with the economic giants of the developing world, China and India. Her appointment was welcomed by climate experts and campaigners. Edward Davey, UK head of the World Resources Institute thinktank, said: “Rachel is a giant and a ball of fire, with a vast hinterland of knowledge and experience and a global network of friends and allies. She will be brilliant and a force to be reckoned with.” Bernice Lee, research director for futures at the Chatham House thinktank, said: “Given what the foreign secretary just said about his priority of using climate and nature as a way to regain soft power for the UK and re-engage with the developing world, Rachel’s extensive experience and network that came from her work with the developing countries and tackling investment challenges on the ground at the World Bank and UN mean she is an excellent fit for the role of climate envoy.”