Forget your carbon footprint. Let's talk about your climate shadow.

Consider these two people: One flies weekly for work; the other lives in a studio apartment and walks to the office every day. On the surface, it’s clear here who has the bigger carbon footprint. Flying is notoriously awful, emissions-wise, and when you compare a weekly flight to the energy use of a small home and the emissions of a daily walking commute, the outcome is obvious.

But here’s a wrinkle: The weekly flier is a climate scientist who travels around the world teaching about the dangers of climate change. The second person works for a marketing agency, making ads like this for an oil company. So who is contributing more to the climate emergency, really?

Almost 20 years ago, a clever campaign by BP brought us the concept of the carbon footprint, a now-ubiquitous tool that’s supposed to help you calculate how much you are personally contributing to climate change. Depending on which calculator you use, your “footprint” might take into account your electricity usage, how many miles you drive and the gas mileage of your car, your water usage, your eating habits, how much you fly, and how much garbage you accumulate. Some calculators offer helpful tips — like switching out your light bulbs or hanging your clothes to dry — or let you compare your carbon footprint to other households in your zip code.

The problem with the carbon footprint is that, as the example of the climate scientist and the oil industry marketer show, our footprints don’t paint an accurate picture of our true individual impact on the climate crisis. And by encouraging eco-minded people to use their carbon footprints as a “guide” to fight climate change, we risk them spending all of their energy on low-impact individual actions that are easy to quantify, like recycling or turning off lights, instead of putting that energy toward broader, more meaningful work, like lobbying local politicians or speaking up at work about wasteful practices. Imagine if Greta Thunberg had decided to devote her attention to using less water or ditching dairy products instead of creating #FridaysforFuture.

Think of your climate shadow as a dark shape stretching out behind you. Everywhere you go, it goes too.

If we have any chance at slowing climate change — which, according to a recent report from the U.N., has put “the world on a catastrophic pathway” — we desperately need a more comprehensive metric. We need something that truly encompasses the total impact each of us has on our climate crisis.

Enter: the “climate shadow,” a concept that I created to help each of us visualize how the sum of our life’s choices influence the climate emergency. Think of your climate shadow as a dark shape stretching out behind you. Everywhere you go, it goes too, tallying not just your air conditioning use and the gas mileage of your car, but also how you vote, how many children you choose to have, where you work, how you invest your money, how much you talk about climate change, and whether your words amplify urgency, apathy, or denial.

The power of your climate shadow is that, unlike a carbon footprint, it includes actions that defy easy calculation (which, as Greta’s #FridaysforFuture strike showed us, almost all high-impact actions do). I have a friend who decided not to have a child due to climate concerns, and another who helps with our local utility company’s green energy program. These choices wouldn’t be counted in a measurement of their carbon footprints, but they would factor into their climate shadows. The climate shadow also includes contagious behaviors, like installing solar panels, giving up flying, or talking about climate change in everyday conversation.

I visualize my climate shadow being made of three parts: my consumption, my choices, and my attention. My consumption would incorporate my lifestyle expectations, like running the air conditioner all summer or desiring two-day shipping when I shop online, as well as my participation in consumer culture (posting about new purchases on Instagram, spending money that goes toward a company or supply chain that is sustainable long-term) and, yes, my carbon footprint. My choices would include how I donate and invest my money, the number of children and pets I have, and what kind of company I work for and the kind of work I do for them. My attention is probably the most nebulous, yet perhaps the most important: How much of my attention is focused on the climate crisis? How many hours am I devoting to climate action? Is it at least as much as I spend watching Netflix, planning my next vacation, or taking a barre class?

By promoting the carbon footprint as the single most important thing for concerned citizens to focus on, the fossil fuel industry ensured that we wouldn’t put our energy toward what truly matters: collective action and activism.

When BP co-opted the concept of the carbon footprint and tied it to small, “feel-good” activities like shortening your showers or hanging your clothes to dry, they crucially shifted the narrative from corporate accountability to personal responsibility. An even more tragic outcome is that by promoting the carbon footprint as the single most important thing for concerned citizens to focus on, the fossil fuel industry ensured that we wouldn’t put our energy toward what truly matters: collective action and activism.

I would argue that individuals don’t need an emissions impact number to begin with. Our climate emergency requires more from us than simply changing our habits, like we might do after getting the readings off our Fitbit or smart thermostat. “People feel like there is power in numbers and ratings,” says Susan Joy Hassol, director of the nonprofit science outreach group Climate Communication, “but I think what's more important is that someone knows that they're doing everything they can. We have to do as much as we can, as fast as we can.”

Still want to reduce your carbon footprint? Great. But you don’t need to calculate the square footage of your home in order to know what to do. “The top five personal actions are one fewer child, be car-free, avoid plane travel, use green energy, and eat a plant-based diet,” Hassol explains. Everything else is pretty much inconsequential. Why? Because the average American’s carbon footprint is 16 tons per year. To meet our carbon emission goals, we would need to reduce each one to 2 tons. No number of eco-friendly light bulbs can do that kind of mathematical sorcery.

Bobby Kennedy once said about our GDP: “It measures everything in short, except that which makes life worthwhile.” Something similar could be said about our carbon footprint: It measures everything except what actually matters. If we are going to work together to keep the worst of the climate crisis from happening, it’s going to require a bracing moral inventory. Each of us will have to undergo a kind of spiritual reckoning, and that type of evaluation can’t be done by a calculator. To know the true expanse of your impact on the planet, I would urge you to overlook your carbon footprint. Instead, look behind you, at your shadow.