A successful Cop26 is essential for Britain and the world. Here's how it can happen | Simon Lewis

Without a clear plan for what he wants to achieve, Boris Johnson risks becoming a bystander at a crucial world summit

In November Boris Johnson will host the most important global meeting ever to take place on UK soil. The outcomes of this UN summit on climate change, known as Cop26, will help shape the fates of billions of people for decades to come. For the UK it is also the first big stress-test of its new role in the world after leaving the EU.

Superficially the chances of success appear high. The US, China, EU, UK and 97 other countries have now stated that by mid-century their overall emissions of carbon dioxide will be zero. The economics are aligned: coal, oil and gas companies are increasingly poor performers, while renewables companies are booming. The escalating costs of climate emergency coupled with the increasingly obvious benefits of an energy transition are rapidly altering the calculus of what is possible.

Related: If Johnson thinks he can charm his way to success at Cop26, he's sorely mistaken | Larry Elliott

Simon Lewis is professor of global change science at University College London and University of Leeds, and the author, with Mark Maslin, of The Human Planet: How We Created the Anthropocene