Human beings have not yet grasped the fact that their very survival hangs in the balance because of manmade planetary challenges such as global warming, which are largely being ignored, an international group of eminent scientists has warned.

The 17 experts, including professors from universities in the United States, Australia, and Mexico, warn in a report published in Frontiers in Conservation Science on Wednesday that the world is in much worse shape than scientists previously thought, and that society seems able to comprehend.

"The scale of the threats to the biosphere and all its lifeforms－including humanity－is in fact so great that it is difficult to grasp for even well-informed experts," they say in their report, which references more than 150 academic studies on environmental challenges.

They say the planet is facing a "ghastly future of mass extinction, declining health and climate-disruption upheavals" that are being made worse by ignorance and inaction.

They explain the lack of action is down to a delay between the erosion of the natural world and the impact of that decay on humanity, making it hard for people to see what is happening.

" (The) mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilization," they argue.

The scientists say climate change and overpopulation will trigger mass migration, wars, and even more pandemics.

But they say people should not give up and that the situation should be like a "cold shower" for world leaders, jolting them into action "to avoid a ghastly future".

They call for changes to global capitalism, education, and equality, and for an alternative to be found to the quest for perpetual economic growth.

The experts also call for an end to the use of fossil fuels and for huge corporations to be shackled.

Paul Ehrlich, head of the Center for Conservation Biology at Stanford University and author of the 1968 book The Population Bomb, was among the 17 scientists who wrote the paper. He told The Guardian newspaper "environmental deterioration is infinitely more threatening to civilization than Trumpism or COVID-19"and said "growth mania" had become the fatal disease facing civilization.

"It must be replaced by campaigns that make equity and wellbeing society's goals; not consuming more junk," he said.

The Russian state-controlled international television network RT noted that the authors called for nations to prioritize the urgent reversal of biodiversity loss and that the report's authors said it is time scientists were blunt about the challenges facing humanity, even if that scares some people.

"Anything else is misleading at best, or negligent and potentially lethal for the human enterprise at worst," the experts said.

The report was published as the United Kingdom government pledged to spend at least 3 billion pounds ($4.1 billion) on nature and biodiversity in the coming five years.

The BBC reported Prime Minister Boris Johnson made the announcement from the One Planet Summit for biodiversity in Paris.

Prince Charles, the son of the UK's monarch, also attended the event and, this week, launched a "Terra Carta", through which he wants companies to support a more sustainable future and do more to protect the planet.