Nuclear power is one of the least damaging sources of energy for the environment, and the green movement must accept its expansion if the world is to avoid dangerous climate change, some of the world's leading conservation biologists have warned.

Rising demand for energy will place ever greater burdens on the natural world, threatening its rich biodiversity, unless societies accept nuclear power as a key part of the "energy mix", they said. And so the environmental movement and pressure groups such as Friends of the Earth and Greenpeace should drop their opposition to the building of nuclear power stations.

In an open letter published on the Brave New Climate blog, more than 65 biologists, including a former UK government chief scientist, support the call to build more nuclear power plants as a central part of a global strategy to protect wildlife and the environment.

The full gamut of electricity-generation sources, including nuclear power, must be used to replace the burning of fossil fuels such as oil, coal and gas if the world is to have any chance of mitigating severe climate change, their letter says.

The letter is signed by several leading British academics including Lord May of Oxford, a theoretical biologist at Oxford University and former chief scientific adviser; Professor Andrew Balmford, a conservation biologist at Cambridge; and Professor Tim Blackburn, an expert in biodiversity at University College London.

As well as reducing the sources of carbon dioxide, the chief man-made greenhouse gas implicated in climate change, the expansion of nuclear power will leave more land to support biodiversity and so curb the extinction of species, they say.

Recognising the "historical antagonism towards nuclear energy" among environmentalists, they write: "Much as leading climate scientists have recently advocated the development of safe, next-generation nuclear energy systems to combat climate change, we entreat the conservation and environmental community to weigh up the pros and cons of different energy sources using objective evidence and pragmatic trade-offs, rather than simply relying on idealistic perceptions of what is 'green'."

It is too risky to rely solely on renewable energy sources such as wind and solar power for replacing fossil fuels because of problems to do with scalability, cost, materials and land use, they explain.

"Nuclear power – being far the most compact and energy-dense of sources – could also make a major, and perhaps leading, contribution …. It is time that conservationists make their voices heard in this policy area," they say.

A golf-ball-sized lump of uranium would supply the lifetime's energy needs of a typical person, equivalent to 56 tanker trucks of natural gas, 800 elephant-sized bags of coal or a renewable battery as tall as 16 "super" skyscraper buildings placed one on top of the other, they said.

The letter was organised by Professor Barry Brook of the University of Tasmania and Professor Corey Bradshaw of the University of Adelaide. The two co-authored a paper in the January issue of Conservation Biology outlining the scientific case of nuclear power in terms of environmental protection. Of seven major technologies for generating electricity, nuclear power and wind energy had the highest benefit-to-cost ratio, they concluded.

"Trade-offs and compromises are inevitable and require advocating energy mixes that minimise net environmental damage. Society cannot afford to risk wholesale failure to address energy-related biodiversity impacts because of preconceived notions and ideals," they said.

Professor Corey told The Independent on Sunday: "Our main concern is that society isn't doing enough to rein in emissions… Unless we embrace a full, global-scale assault on fossil fuels, we'll be in increasingly worse shape over the coming decades – and decades is all we have to act ruthlessly.

"Many so-called green organisations and individuals, including scientists, have avoided or actively lobbied against proven zero-emissions technologies like nuclear because of the associated negative stigma," he said.

"Our main goal was to show – through careful, objective scientific analysis – that on the basis of cost, safety, emissions reduction, land use and pollution, nuclear power must be considered in the future energy mix," he explained.

The letter aims to convince people of the potential benefits of nuclear power in a world where energy demand will increase as the climate begins to change because of rising levels of greenhouse gases, Professor Corey added.

"By convincing leading scientists in the areas of ecological sustainability that nuclear has a role to play, we hope that others opposed to nuclear energy on purely 'environmental' – or ideological – grounds might reconsider their positions," he said.

* This article originally reported that an open letter by more than 65 biologists had appeared in the journal Conservation Biology. In fact, it appeared on the Brave New Climate blog. 14/1/15