A heated exchange between scientists helped to bring home to delegates that there is still at least some dissent from the scientific consensus on climate change.

The Channel 4 documentary called the The Great Global Warming Swindle was aired in the UK just days before the conference. Using an array of scientists and experts, it argued that sun spots and solar radiation, exacerbated by water vapour in the atmosphere, were the real drivers of climate change, not human activity.

One of the scientists who took part in the programme, Piers Corbyn, founder and managing director of the forecasters Weather Action, was in the audience. Come the Q&A session, he challenged the two scientists on the panel over the views they had just stated that average temperatures are rising as a result of greenhouse gasses generated by human activity and unleashing a panoply of dangerous consequences.

The panellists, Professor Bill McGuire, director of Benfield UCL Hazard Research Centre and Professor Julia Slingo, director of climate, National Centre for Atmospheric Science, acting director, Walker Institute for Climate System Research, University of Reading, strongly rebutted Corbyn’s challenge.

Slingo responded first. “We are very confident that the global warming effect is physically robust,” she stated. “No assumptions go into physically based models. We cannot twiddle knobs to support our assumptions.” Slingo said she was in no doubt that it was CO² emissions driving climate change. “We’re the cause and we’re watching the consequences now.”

McGuire was in complete agreement. “CO² levels of this magnitude have never happened before and it’s entirely down to human activity.” To deny that was to deny the greatest threat to future life on the planet.

Helen Yates is editor of Global Reinsurance.