The World Economic Forum, which organizes the annual gathering of political and business leaders in the Swiss ski resort of Davos, says a failure to deal with and prepare for climate change is the potentially most costly risk facing the global economy over the next ten years.

The WEF says Thursday that it's the first time that an environmental concern has topped the list of global risks in the 11 years it's assessed them. The survey of almost 750 experts and decision-makers was conducted in the fall of 2015 before the global warming targets agreed on in Paris in December. Respondents were drawn from a variety of fields, geographies and ages.

The most likely risk to the global economy was identified as large-scale involuntary migration.