The last time Californian climate scientist Peter Kalmus was on an airplane was in 2012: He says it made him feel physically sick and like he was “stealing” from his children’s future, and vowed never to fly again.

US President Donald Trump’s administration has made no secret of its disdain for climate science, but that hasn’t stopped some ordinary Americans from finding ways to drastically reduce their own carbon footprints, hoping to persuade others through their examples.

Kalmus was pursuing his post-doctoral studies in 2009 when he became increasingly concerned about the prospect of climate breakdown, tipping points such as the thawing of the Earth’s permafrost triggering runaway global warming that wreaks havoc on weather systems.

“I was shaking people by the lapels, posting screeds on Facebook, not really getting anywhere,” he told AFP in an interview from his home in a Los Angeles suburb.

“Eventually, it dawned on me that I should maybe bring my actions into alignment with my beliefs.”

Drawing upon his expertise as a scientist, he calculated the emissions associated with various aspects of his life and was surprised to learn that electricity consumption made up a tiny portion compared to air travel.

“So I started focusing on flying less. I tried being a vegetarian for a month, and I liked it better,” he said, quickly realizing that, rather than feeling like sacrifices, the changes he made were improving his sense of wellbeing.

Read more: AFP