In the latest edition of its Global Risks Report, the World Economic Forum ranks environmental threats at the top of the list for the third year in a row - both in terms of impact and likelihood.
Extreme weather events, exacerbated by climate change, are listed as the risk most likely to happen over the next 10 years.
"Of all risks, it is in relation to the environment that the world is most clearly sleepwalking into catastrophe," the report warns.
Environmental concerns account for three of the top five risks by likelihood and four by impact.
2018 saw unprecedented heatwaves, storms and floods across the globe, and global greenhouse gas emissions continued to grow last year, with the current concentration of carbon dioxide in the atmosphere the highest it has been in 3 million years.
'Failure of climate-change mitigation and adaptation' comes in second place both for the list of most likely risks and impact, reflecting respondents' increasing concerns about environmental policy failure.
The report says: "The results of climate inaction are becoming increasingly clear. The accelerating pace of biodiversity loss is a particular concern."
A World Wildlife Fund report from last year highlighted the extent of the challenge we face - with loses in vertebrate species averaging 60% between 1970 and 2014.
The report's findings are based on the annual Global Risks Perception Survey, which asks the Forum's network of business, government, civil society and thought leaders to gauge the risks facing our world.
The Global Risks Report 2019 has been released ahead of the World Economic Forum's Annual Meeting in Davos.
As well as identifying potential dangers facing the world in the coming year, the report urges governments and organizations to address the impact of specific threats and make preparations to contain potential fallout should they occur.