Around 270 private jets were flown into Switzerland by Davos participants between Sunday and Tuesday, according to the World Economic Forum (WEF).
The total number could be higher given that a number of delegates will remain in Davos – where the threats posed by climate change have been high on the agenda – until later in the week.
Releasing the official data on Wednesday, the WEF estimated a 14% reduction in the number of private jets flown into and out of Zurich and St Gallen airports year-on-year.
However, it acknowledged that "the data is not always easy to determine," as busy periods often forced flights to include additional legs in their journeys – meaning that one trip to Davos could be divided into four separate flights.
Based on the average number of daily flights into and out of Zurich, the WEF said "we could assume that there have been in the region of 185 extra flights over the three days of the conference." It estimated that 43 additional return flights were made to St Gallen by Davos participants between Sunday and Tuesday.
During this year's meeting, New Zealand Prime Minister Jacinda Ardern urged fellow world leaders to take action on climate change at this year's event, while former U.S. Secretary of State John Kerry warned people would die if the Trump administration failed to address the issue. Meanwhile, the CEO of Ikea and chairman of Carlsberg both told CNBC that sustainability was vital for every modern business model.
The WEF also flagged climate change as a major global risk ahead of the event, warning that a breakdown in international cooperation was hampering efforts to tackle the threat.
The WEF's data release came after airline Air Charter Service (ACS) predicted on Monday that around 1,500 private jets would fly in and out of Davos this week.
Andy Christie, the company's private jets director, said in a press release on Monday that the firm had analysed private jet activity around the event since 2013.
"Last year was the busiest year for private jets so far, showing an 11% increase on 2017, with more than 1,300 aircraft movements. If we see a similar increase this year, we could be looking at almost 1,500 aircraft movements over the six days," he said.
According to ACS, most private jet flights to the WEF in Davos came from Germany, France, the U.K., the U.S., Russia and the UAE.
The WEF said that although its data did not cover the entire week, the official numbers were "a far cry from the 1,500 flights mentioned in some news reports, which appear to be based on marketing literature from a commercial operator."
Independent audits in 2018 established the Forum's annual meeting as a sustainable event, meaning the WEF must continue to demonstrate efforts in managing its emissions.
The WEF said it would calculate the meeting's carbon footprint and compensate for it by buying the corresponding amount of carbon credits from South Pole, a social enterprise that supports emissions reduction projects.
"For those who do travel to Davos by plane, we fully offset the flights – private or otherwise," the WEF said in a statement.
"This year's drop in private air traffic is a sign that participants are taking the environmental impact of their travel more seriously… We have been offering incentives to participants to use public transport for some years. We also ask that they share planes if they have to use them – something that has been gaining popularity in recent years."