There was a moment when Janisse Ray realized she couldn’t call herself an environmentalist and an activist and keep traveling by airplane.

She hasn't been on a plane in almost a decade. In this episode of terrestrial we find out how giving up flying has changed Ray's career and her relationships.

Her decision may seem radical, or ahead of the curve, but it might be one that more of us face in the years ahead.

In June a heat wave swept through the southwest. It was so hot that airplanes couldn’t take off. In Phoenix temperatures hit 119 degrees Fahrenheit and dozens of flights were canceled.

Hotter weather makes for thinner air so airlines had to drop weight by paying their customers to give up their seats — or delay flights until it cooled off later in the day.

It was one of those moments where it feels like nature might be trying to tell us something. But this is about more than just planes not being able to take off because of hotter weather, it’s also about the fact that planes emit a lot of carbon, which drives climate change and makes for more heat waves.

And for many of us, flying is the single largest contributor to our annual carbon emissions.

The average American emits roughly 16 tons of carbon dioxide each year. Scientists say that if we want to keep the planet safe for human and animal life we need to drastically reduce our carbon emissions — down to two tons of carbon dioxide per year.

To put that in perspective, if you fly from New York to London you’ve just about hit your quota for carbon emissions for the year.

But, could you give up airplane travel for the sake of the climate? If you stopped flying how would your life and your relationships change? Please share your thoughts in our Facebook group.

You can hear more from terrestrial by subscribing on iTunes.

You can read an essay Janisse Ray wrote about choosing to take the train, first published in Orion Magazine.

Curious about your own carbon footprint? We’d recommend UC Berkeley’s “Cool Climate Calculator”.

Thank you to Kim Nicholas, a climate scientist at Lund University in Sweden, for her help with this episode. She recently published a paper that takes a close look at the leading contributors to our carbon footprints.