Last fall, after reading a comprehensive report on the perilous state of climate change, the urgency of the problem hit me with renewed force.

For the first time, 195 nations backed a consensus statement saying that humanity is “extremely likely” (greater than 95 percent confidence) to be the dominant cause. That’s about the same confidence doctors have that smoking causes cancer.

Also, for the first time, the panel declared last-ditch solutions, like geoengineering, were off the table: The total cost of sucking carbon out of the atmosphere is anticipated to be greater than the cost of implementing reductions in the first place.

That means we have no choice but to change our collective path right now. In the meantime, climate change–connected events will continue to accelerate in frequency and severity.

We’ve reached a point where the majority of people now accept that climate change is happening. But what should we do about it? A recent survey of British citizens found that 63 percent of respondents fell into this middle category: They accept climate change is happening but haven’t yet taken substantive action. They’re experiencing “stealth denial.” Here are common responses representing the three types of stealth denial the survey discovered, from the Guardian: Emotional Denial: "I don't feel uneasy about climate change"; Personal Denial: "My daily actions are not part of the climate change problem"; Practical Denial: "There is nothing I can do personally that will have any significant effect on limiting climate change"

Before I read the September report from the United Nations, I definitely fell into the latter two categories. It was abundantly clear to me that “we” needed to take “action” to prevent the worst effects of climate change. But that morning, it hit me: I couldn’t stop thinking, “But what does that mean for me on a personal level?”

That September morning, after an emotional morning of tears and tweets, I decided to take action.

I’m never going to fly again.

My reason was simple: Flying used to be my biggest personal source of CO2 emissions. With a single action, I was able to cut my personal impact on climate change by nearly 50 percent.

Shortly after my decision, I wrote: My wife and I realized that the “substantial and sustained reductions” called for by the Intergovernmental Panel on Climate Change (IPCC) had to start with us. World governments will never agree in time to coordinate reductions in greenhouse gas emissions. If anything is to change, it will have to come from individuals taking ownership of the problem themselves.

It felt like a small gesture. But I quickly realized, from the sheer amount of press my decision received, that our personal response to climate change is something many other people are grappling with. Fox News called me a “sniveling beta male.” Crazy people even wanted me to commit suicide. Apparently, it’s not manly to try to put your money where your mouth is and live up to your values. Still, by my count, my actions could have motivated as many as hundreds of people to take a similar no-fly pledge for the climate.

The vast majority of Americans fly only very rarely. For those in developing countries, air travel is a luxurious dream. Until recently, I had a carbon footprint twice that of the average American (and, likely, among the top 10 percent of all humans on Earth). That huge footprint came despite being vegetarian, recycling, owning only one car, and generally believing I was doing enough to make a difference. (The majority of my air travel was to support climate change adaptation projects in Ethiopia.)

There’s a dangerous line of reasoning embedded here: that incremental steps will be enough to solve climate change. They won’t be. Since the implementation of the Kyoto Protocol in 1990, global emissions have actually risen by 61 percent, reaching a new record high in 2013. A growing number of scientists are starting to embrace the fact that it will take bold action to make a dent in our current trajectory of increasing emissions. There was even a recent conference in the United Kingdom dedicated to this theme. Some even go as far as saying that without big steps very soon, the world’s youth would have a scientific basis to rise in mass revolution.

So, I decided to take a big step of my own.

In one of my interviews, the host called a sudden realization like mine a “climate epiphany.” That seems about right. I knew in my mind that climate change was a big problem—heck, I’m a scientist who writes about weather and climate every day—but I didn’t let myself believe that quite literally, among all humans on Earth, I was among those who contributed to the problem the most. Which means, of course, it was on me to do something about it.

Obviously, I still have a lot of work to do. I’m not carbon neutral yet, and I don’t believe in offsets. Plus, I still have a day job. Like many others, I’m not willing to give up all aspects of my lifestyle, but I am willing to do what’s necessary.

So what does that look like, in practice?

My world is much smaller now, and that’s both good and bad. I’ve found myself exploring more around where I live. One of the biggest downsides is giving up international travel, which I love. But I’d rather do my part now so the people who actually live in all those exotic places can continue to do so. Maybe, someday soon, there will be a low-carbon way to travel to those places again. Here’s hoping. But for now, for me, the climate is more important.

One of the most common questions I’ve received since I stopped flying is, “How does it affect your job?” It’s been a relatively easy transition so far. I was able to work remotely to support my project in Ethiopia, and I’m continuing to do interviews and meetings by video conferencing. But invitations to in-person meetings are picking up, and I’m finding myself being much more choosy than I otherwise would have been. Increasingly, there’s a thought process of “Is this worth it?”— which I suppose should have been there all along.

This week, I put my no-fly vow to the test for the first time. I took the bus from Wisconsin to Atlanta.

The destination was the American Meteorological Society’s annual meeting. Thousands of meteorologists are here in Atlanta from around the world, and it's a chance to share the latest research and meet fellow weather nerds.

I chronicled the journey in a series of tweets.

Here’s the route I took, about the same distance as London to Rome:





Which by bus took 28 hours. One way. Why did I decide to take the bus? Here's the stats.





From both a climate and financial standpoint, there’s a clear case to take the bus. From a butt-numbness standard, the bus isn’t quite there yet in the United States. However, the rise of limited-stop intercity operators like Megabus is helping the United States to quickly catch up to the rest of the world in terms of frequency and comfort on long-haul bus rides. In Chile, a spread-out country that has embraced long-distance buses, you can easily and cheaply snag a first-class quality experience with meals, Internet, live TV, and a lay-flat bed in every seat.

Buses are the most climate-friendly mode of transportation per passenger mile next to walking or riding a bike. This makes sense: There’s no need to accelerate hundreds of tons of aluminum to nearly the speed of sound, or to push thousands of tons of steel along 19th-century rail routes. Even a Prius is dragging along lots of extra weight just to move you down the road, especially if you’re solo, as most car trips are.

My bus ride would have been even cheaper if I hadn’t booked at the last minute. Two weeks prior to my departure, the Megabus fare between Madison, Wis., and Atlanta was $80 round trip.

Besides the baby crying across the aisle, the loud-talker a few rows behind me, and my seatmate who slept the last hour of the trip on my shoulder, my bus trip wasn't actually that bad. I wrote a piece for Slate on the bus, had an hour to walk around downtown Chicago, met two high-school students who were scouting colleges and a 74-year-old grandmother traveling to visit her 92-year-old mother, and otherwise enjoyed my window seat.

Once I arrived, my colleagues were a bit incredulous but generally supportive. But still, I heard the familiar refrain: “Kudos, but I just don’t think I could do that.”

Now, riding the bus is not for everyone. But I do think everyone can make a significant change to his or her leading source of personal emissions. That may be transportation, it may be your diet, it may be your source of electricity, or it may be something else. Nearly 25 years ago, when the Kyoto Protocol was implemented—the first international climate treaty, which the United States didn’t sign on to—there was still time to make incremental changes and have them add up gradually. That time is over. Now, we need to take bold action—in every aspect of our lives, to the extent possible.

What I’m doing works for me, but it might not work for everyone. Bold action (like refusing to fly) might pose undue stress on our families or get us fired. That’s when we should ask ourselves: If I’m worried about the future welfare of my children (or other people’s children), what’s the most I could reasonably do to make a difference? One person’s actions won’t make airlines revamp their schedules and fly fewer flights. And it’s true: The planes I would have taken to and from Atlanta took off whether or not I was on them. But 1 million people’s actions might make a difference. I’ve also been asked about whether the world economy would be in huge trouble if everyone stopped flying. Well, I doubt everyone will ever stop flying. Furthermore, my goal is to get people to think about the fact that if we continue on our current emissions path—aviation is the fastest-growing emissions source globally—climate change itself could decimate the economy.

Could riding the bus be a game-changer for the climate? Transportation is second only to coal-dominated power plants in terms of U.S. emissions. There’s a lot of room to improve. Now, we all know the United States doesn’t have a nationwide high-speed rail system like some countries in Europe or Asia (though one is theoretically in the works). We’ve instead chosen to focus on our interstate highway system, which is the most extensive in the world.

Given the pressing nature of climate change, and the decades it would take to spin up a reliably fast rail system in the United States, I think we’re better off embracing our current system (for now) and getting it to work for us.