Playing the doomsday card on climate change is not the best way to achieve collective global action needed to counter it, according to leading commentator on global warming Prof Chris Rapley.

The need for that action could not be clearer in light of evidence showing human activity was “interfering with the life-support system of the Earth” which had been relatively stable for millions of years, said the professor of climate science at University College London.

“In many respects what is happening to the Earth is one of the most extraordinary narratives in the history of the universe with the end pages still blank,” said Prof Rapley, who was in Dublin to give a lecture hosted by the Environmental Protection Agency on why it is so difficult to communicate climate change.

He highlighted the time frame within which climate change was happening, and indications global warming was occurring more quickly than anticipated, especially in polar regions – and yet there was a widespread “disconnect between evidence and action”.

“Let’s assume we are the only life form in the universe. It’s 14 billion years since the ‘big bang’; four billion years since the planet was formed. Everything has happened really very slowly up to a few decades ago. In the last 30 to 40 years human beings have been affecting the metabolism of the planet.”

Up to that point, damage to the planet caused by humans was interference “on a landscape scale”, and relatively minor, he said. Carbon dioxide emissions over recent decades had upset the energy balance of the planet; “that is qualitatively a different level of interference.”

If the Earth was considered a space ship, “we are tinkering around with its life-support functions”, he explained.

Discussion oversimplified

The climate system was very complex, Prof Rapley said, yet discussion around it was often oversimplified. In addition, there were “gaps in our knowledge, and many scientific uncertainties, some of which are fundamentally unknowable” but this could be distorted in emotional argument.

It was extremely difficult to predict precisely what the future holds and to determine exactly what actions to take, he noted. In addition, there were economic considerations, political implications and ethical questions that further complicate the way forward. “In many ways, it’s down to what risk you are prepared to take.”

“The irony of the climate change story is the more vividly you deliver the message, the more likely you are to generate emotions of fear, guilt, unhappiness and in particular helplessness,” he added.

Art and theatre could play a major role to play in breaking through uncomfortable feelings about climate change – what psychologists call cognitive dissonance – which leads to a shutting-down process and forms of denial “because the implications are unbearable”.

The best ways of countering this was with stories that were “engaging; meaningful, actionable, hopeful and experiential”, he believed, though climate scientists were uncomfortable in this space because of their training. Explaining “what you feel and think over a pint” was probably a much more useful entry point into the debate.

The scale of the problem, the urgency needed and the complexities of climate change could be overwhelming, he admitted. Against that, people needed hope; so in communicating causes and global response needed, a “very tricky” balancing was required.

Collective action at the speed and scale required meant politicians and policymakers, commerce and businesses and the general public had to be on board. If one element of that triangle was missing, failure was inevitable.

Battle hardened from engagement with climate sceptics, he pointed to his distinctive brand of optimism in trying to secure meaningful action on climate change: “I’m full of dark optimism. It’s pretty difficult, but you should never give up.”

A former director the British Antarctic Survey and the Science Museum in London, Prof Rapley paid tribute to the work of the Citizens’ Assembly in Ireland for promoting public discussion and dialogue, and helping to break down what for many was “a taboo subject”.