Boris Johnson is to tell other world leaders that the climate emergency is “driving insecurity” as he uses the first UN security council session chaired by a British prime minister in nearly 30 years to set the scene for the Cop26 climate conference in Glasgow. The prime minister will chair a virtual session of the security council which will also be addressed by David Attenborough, who will warn leaders that without urgent and coherent action the pace of change could become unstoppable. While the security council has regularly discussed the threats from the climate emergency for almost 15 years, Johnson’s decision to focus on the subject will be seen as a statement of intent ahead of Cop26, due to be held in November. In words released ahead of the virtual meeting taking place on Tuesday, Johnson said the security council “is tasked with confronting the gravest threats to global peace and security, and that’s exactly what climate change represents”. He said: “From the communities uprooted by extreme weather and hunger to warlords capitalising on the scramble for resources – a warming planet is driving insecurity. “Unlike many issues the council deals with, this is one we know exactly how to address. By helping vulnerable countries adapt to climate change and cutting global emissions to net zero, we will protect not only the bountiful biodiversity of our planet, but its prosperity and security.” Attenborough was to tell world leaders that Cop26 could be “our last opportunity to make the necessary step-change” over changing climate. He said: “If we bring emissions down with sufficient vigour we may yet avoid the tipping points that will make runaway climate change unstoppable. If we objectively view climate change and the loss of nature as worldwide security threats – as indeed, they are – then we may yet act proportionately and in time.” Some of the most vulnerable countries are also planning to make an appeal to rich nations at the security council meeting, calling for more action to reduce greenhouse gases, and aid and other assistance to help make poor countries more resilient to the impacts of climate breakdown. Kat Kramer, the climate policy lead at the charity Christian Aid, said: “Millions of the world’s poorest people are already living with the impacts of climate change, which is forcing displacement, devastating livelihoods and putting pressure on communities who are competing over resources such as land and water. “In some countries, these impacts become the drivers of local conflicts which can be instrumentalised by leaders and escalate into violence and war. This threat of violence and insecurity threatens to undermine international peace and security.” Funding for poor countries to cope with the impacts of the climate crisis will be a key focus at Cop26. The UN secretary general, António Guterres, warned last year in an interview with the Guardian that the longstanding pledge by rich countries to provide $100bn (£70bn) a year to developing countries from 2020 was unlikely to be met. Of the tens of billions of climate finance that are provided each year, only about a fifth goes to helping countries adapt to the impacts of global heating. Along with the US, China, Russia and France, the UK is one of the five permanent members of the security council but has not chaired a session since John Major did so in 1992. There are also 10 non-permanent members, elected for two-year terms, which are Estonia, India, Ireland, Kenya, Mexico, Niger, Norway, St Vincent and the Grenadines, Tunisia and Vietnam. The UK has an official climate target of reaching net zero emissions by 2050. A new target announced in December promises a reduction of 68% in annual carbon emissions by 2030, compared with 1990 levels, further and faster than any other major economy in the next decade.