The UK has just come through its hottest summer since at least 1884. Not one blistering afternoon, but three months of drought, five heatwaves, and the worst wildfires on record. In France and Spain, fires drove hundreds of thousands of people from their homes, and the El Niño now building in the Pacific is, the Met Office says, the largest in more than a century – likely to make 2027 the hottest year the world has ever measured.

Meanwhile at Westminster, the Climate Change Act – passed in 2008 with just five MPs voting against, and strengthened by Theresa May in 2019 to commit the UK to net zero by 2050 – has gone from settled law to a target for populists who promise to tear it up. Nearly two decades of cross-party agreement is fraying just as the tide is starting to come in.

These are all one story. It is what happens when a problem measured in centuries meets a political system that resets every five years. That mismatch is the subject of this year’s Rationalist Press Lecture, the successor to the Voltaire Lecture, which ran from 1968 to 2025.

Book your ticket for the Rationalist Press Lecture 2026 today.

Professor Corinne Le Quéré CBE has spent her career counting carbon. For 13 years she led the Global Carbon Budget, the international effort that tells us each year how much we have emitted, how much the oceans and forests have absorbed, and how much room is left. She was founding Chair of France’s High Council on Climate and spent a decade on the UK Climate Change Committee, putting independent evidence in front of governments of every stripe – even when they’d rather not hear it.

In the Rationalist Press Lecture 2026, she will set out where the science now stands, what a carbon budget actually is, and why a date set in law is not the same as a plan. And she will look at the harder, more uncomfortable questions. What does it take for a small group of scientists to tell a government it is off track, and for that to matter? In a democracy, is it even legitimate for a parliament to seek to bind its successors for decades into the future? And how can we sustain the votes necessary to secure a safe and sustainable future for the one planet we have – and for all of us who live on it?

About Professor Corinne Le Quéré CBE

Professor Corinne Le Quéré CBE FRS is Royal Society Research Professor of Climate Change Science at the University of East Anglia, where her research examines how the climate and the carbon cycle shape each other, and how the oceans absorb the carbon we emit. In 2004 she instigated the Global Carbon Budget, the annual international effort to track global emissions and carbon sinks, and led its update for 13 years. She directed the Tyndall Centre for Climate Change Research from 2011 to 2018, was founding Chair of the French High Council on Climate, and served on the UK Climate Change Committee from 2016 to 2026. She authored three assessment reports of the Intergovernmental Panel on Climate Change, which shared the Nobel Peace Prize in 2007.

Her awards include the Dr A.H. Heineken Prize for Environmental Sciences from the Royal Netherlands Academy of Arts and Sciences, the Prince Albert I Medal, and the Vernadsky Medal of the European Geosciences Union. She was made a Chevalier of the French Legion of Honour in 2019, and appointed CBE the same year for services to climate change science.

About Janet Ellis MBE

Janet Ellis MBE is a broadcaster, actor, writer, and the President of Humanists UK. A longstanding advocate of humanism, she became a patron of Humanists UK in 2014 for her exploration of the human condition through the arts, and was awarded an MBE in 2016 for services to charity and the theatre.

About the Rationalist Press Lecture

The Rationalist Press Lecture takes on any question worth asking – in science, philosophy, culture, or the world around us – and examines it in the light of reason and the humanist commitment to living well. The medal is awarded each year to someone who has made a significant contribution in one of those fields, and the lecture is chaired by the President of Humanists UK.

The series is the successor to the Voltaire Lecture, which ran from 1968 to 2025. Past speakers include Michael Foot, Sir Hermann Bondi, Baroness Barbara Wootton, Sir Ludovic Kennedy, Professor Brian Cox, Bonya Ahmed, Bettany Hughes, Professor Nichola Raihani, Dr Caroline Dodds Pennock, Professor Steven Pinker, and Professor Anil Seth.