It came as a bit of a shock: Erik Solheim, head of the United Nations Environment Program (UNEP), has resigned.
For all his talk about the urgency of tackling environmental problems such as the species extinction crisis, plastic pollution and climate change, the last thing you would expect is that in just 22 months, he spent nearly half a million dollars jet-setting around the globe.
Yet exactly this is among the main reasons he stepped down on Tuesday, as disclosed by an internal UN audit.
Sure, leaders need to travel to do their job. But it seems Solheim flouted UN rules and regulations in accounting for travel, sparking a potential budgetary crisis as some countries threatened to withhold UNEP funding as a result.
In these days of waning trust in public bodies, it's important to maintain the legitimacy of a key environmental institution.
In case you don't already know, flying has the highest carbon footprint per person of any form of travel.
Although air travel makes up only about 2 percent of global greenhouse gas emissions — or 5 percent of manmade warming, if climate impact of cloud formation and other emissions are counted together — what's most troubling is that air travel is projected to grow massively in the years to come.
It really is a dilemma: You can't forbid people from flying, yet hopping on a plane does have such an outsized climate impact.
The deeper problem is systemic, since current prices for air travel don't reflect the externalized costs of climate impacts.
In other words, future generations will carry the true price of our cheap tickets — in the form of ever more heat waves and severe storms, destructive wildfires, rising sea levels inundating coastal communities, and health impacts we don't necessarily even understand the extent of yet.
But like many climate policy proposals, these still seem too far off to make the rapid change we're told the world needs in order to avert climate catastrophe.
So some people are taking things into their own hands
The trending hashtag #IStayOnTheGround embodies a movement out of Sweden, where activists have decided to personally stop flying in planes, to take a stand for climate action.
Under the shadow of "flygskam," or a personal sense of shame over flying, this noble bunch is part of a growing movement of anti-flying activists who have taken it upon themselves to set an example.
Solheim was justly criticized for exaggerated air travel — after all, he worked for an environmental organization that includes climate change among its main concerns.
But it's not just about the climate hypocrisy.
Such irresponsible actions threaten to delegitimize an important supranational body, which has done crucial work to tackle environmental problems.
The audit report said Solheim was away from the office 80 percent of the time. He allegedly allowed selected staff to work from Europe instead of from UNEP headquarters in Nairobi.
Solheim was also criticized for promoting a massive Chinese infrastructure project despite environmental concerns, and for sponsoring a Volvo race without disclosing it.
In his own defense, Solheim told Norwegian press that the audit had errors in it, and that he needed to travel so much to make the work of UNEP visible. He claimed certain elements were targeting him for being a reformer.
But in sum, his actions paint a questionable picture of a corrupt politician using a position of privilege to his own advantage.
The same, sad old story — which erodes confidence in public institutions and provides fodder for far-right attacks on multilateral bodies.
I would expect more from a leader. Leaders should be role models. They should be the change they want to see in the world, inspiring others to do the same.