Imagine the impact of the second world war. This, according to former World Bank chief economist Nicolas Stern, captures the scale of the economic impact of climate change, left unchecked. The social and environmental effects are predicted to be similarly catastrophic. Given the widely accepted need for rapid and deep cuts in CO2 emissions, the response to E.ON's application to build the UK's first coal-fired power station in 30 years, at Kingsnorth in Kent, and news that business secretary John Hutton seems minded to give it the go-ahead, has been bewilderment and anger.

A new high point of opposition starts this weekend as the Camp for Climate Action embarks on an eight-day protest to press the government and E.ON to abandon the scheme. This is no fringe issue: they will be taking action to stop a proposal potentially so destructive that increasing numbers of scientists are speaking out against it.

Over recent years scientists have become increasingly vocal about the need to take action to cut CO2 emissions. In 2005, the science academies of the G8 countries along with Brazil, China and India - three of the largest emitters of greenhouse gases in the developing world - signed a joint statement to push political leaders to tackle climate change as an urgent priority. By 2008, this group was calling for a rapid, planned transition to a low-carbon economy.

Opposing plans for new coal-fired power plants in developed countries has become an international frontline of climate change politics. Jim Hanson, senior climate change scientist at Nasa, wrote to Gordon Brown last year calling for a ban on new coal, stating that Brown's decision on Kingsnorth has "the potential to influence the future of the planet". This is because coal is one of the most polluting and carbon-intensive forms of fossil fuels - producing twice the carbon emissions per unit of electricity as gas. Coal is the cause of fully half of the fossil fuel-caused increase of CO2 in the air today, and there is plenty left to burn. If we don't limit the use of coal, avoiding catastrophic climate change will become impossible.

However, Paul Golby of E.ON, in these pages yesterday, dismissed anyone opposed to his company's plans to annually emit at least 6m tonnes of CO2 into the atmosphere - more than the total emissions of Costa Rica or Cameroon - as naively ignorant of power generation realities. He has tried to scare the public into thinking that new coal is necessary to keep the lights on.

Yet the independent energy consultancy Pöyry, in a report out today (ilexenergy.com), gives the hard numbers showing projected demand can be met, while respecting strict emissions limits and energy security concerns, using renewables and not resorting to new coal. Meanwhile Cambridge professor of physics David MacKay's book Without Hot Air presents five different plans of how we can meet the UK's energy needs and radically reduce emissions. Of course there are no easy answers, but for Golby to deny that there are no answers other than business as usual is dangerously untrue.

Let's be clear. Either coal usage must stop, or the CO2 released from any coal burned must be kept out of the atmosphere, by burying it under the sea, using an unproven technique known as carbon capture and storage. The Royal Society has made a clear proposal that all new coal plants must capture 90% of their CO2 emissions by 2020, or have their operating permits revoked. If agreed, this would send a clear signal that if carbon capture and storage works, coal use is acceptable, otherwise it is not. However, last month, when E.ON and energy minister Malcolm Wicks were before parliament's environmental audit committee, both evaded accepting the Royal Society proposals' impeccable logic.

E.ON's preference is to use the carbon market to reduce emissions. This won't deliver real cuts, as its own business case shows: Golby believes E.ON can participate in the European scheme, provide competitively priced electricity and turn in a good profit for 20-40 years by burning the dirtiest fuel. Such delusions must be exposed: it is not possible to keep releasing large quantities of CO2 into the atmosphere and avoid the social, environmental and economic consequences of climate change.

The Climate Camp is creating space for serious debate about the kind of world we want to live in. More than that, the campers give shape to a force that can perhaps override the profits-now catastrophe-later logic of the government and E.ON: they form a broad-based movement of people committed to a socially just transition to a low-carbon society. I certainly don't want to live in E.ON's world, where business as usual trumps avoiding dangerous climate change. So I'll be joining the campers in Kent. Anyone else with concerns about the future should do the same.

· Simon Lewis is a Royal Society research fellow at the Earth & Biosphere Institute, University of Leeds

s.l.lewis@leeds.ac.uk