The Guardian’s global environment editor, Jonathan Watts, talks to eminent scientists Katharine Hayhoe and Peter Stott whose work over the past decades has helped prove that the planet is warming and that humans are responsible. Jonathan asks them about their struggle to convince governments and policymakers of the urgency of the situation and whether they feel optimistic about the progress being made at Cop26. On Tuesday, Carbon Action Tracker projected that the world is on track for disastrous levels of global heating far in excess of the limits in the Paris climate agreement, despite a flurry of carbon-cutting pledges from governments at the UN Cop26 summit. Temperature rises will top 2.4C by the end of this century, based on the short-term goals countries have set out. The Guardian is editorially independent. And we want to keep our journalism open and accessible to all. But we increasingly need our readers to fund our work.