The level of debate about climate change in the General Election campaign has been like arguing over who is buying the drinks in the bar of the Titanic, a leading scientist has warned.

Professor Sir Brian Hoskins, chairman of the Grantham Institute - Climate Change and the Environment at Imperial College London, said discussion was at a "trivial level" in the election compared to the dangers the world faced from rising temperatures.

He made the comments as prominent scientists from international research institutions came together to publish a call on Earth Day for strong global action to limit climate change, warning the window of opportunity was closing fast to tackle the problem.

The "Earth statement", published by the Earth League, calls for crucial UN climate talks in Paris in December to secure a deal limiting temperature rises to 2C and transforming the global economy to low-carbon one with emissions near zero by 2050.

The science-based statement sets out key elements for climate action, including keeping within a safe "carbon budget" by leaving at least three-quarters of known fossil fuels in the ground, a fair distribution of action between countries, measures to unleash a wave of climate innovation and protection of vital ecosystems which absorb carbon, such as forests.

Sir Brian likened the shift from fossil fuels to low-carbon technology to the move away from slavery - which people had argued against because it would wreck the economy but had been achieved with the discovery of oil, coal and gas to power production.

Now the world had used up as much fossils as it could and had to move into the next stage with renewables which were more sustainable, he said.

Asked about how little climate change was being discussed in the election, he said: "It's like Titanic sailing into waters with icebergs, and yet what we hear is a debate in the bar about who is going to buy the drinks.

"Get real, we're all in this boat and there's some pretty nasty stuff out there and the conversation is just at a trivial level compared to the danger we have."

He added: "Unlike the Titanic there are major opportunities. The only opportunity for them was to get out safe, we actually have a chance for going from a world dominated by fossil fuels into the next stage."