These days, brands are all about selling you something more sustainable. In just the past week, we’ve seen Apple launch its first carbon-neutral products and Amazon start to share pollution reports for individual devices. 

GM sponsored a major hub for events during New York City’s Climate Week, coinciding with a United Nations climate summit. I walked past its electric vehicles displayed in a conference hall outside a panel about living in a changing climate.

Down the hall, I grabbed “locally sourced, plant-based nourishments” from a cafeteria featuring recipes by Hellmann’s (maker of the mayonnaise). Trying to decide between a chicken farro bowl and a Tuscan kale salad, I realized that the numbers on the menu didn’t represent calories but greenhouse gas emissions from each item.

As an environmental reporter, a lot of my job is sussing out how legit companies’ sustainability pledges really are. I’ve scanned a lot of brands’ sustainability reports and have seen their greenhouse gas emissions rival that of small countries. It’s made me a little wary of big corporations passing the buck onto consumers to make more sustainable lifestyle choices. At the same time, a lot of people I know want to make more environmentally friendly choices. And I went with the kale salad, which had a smaller carbon footprint than the chicken bowl. 

How much of a difference did that little decision make? Not much, honestly. Even so, there’s a bigger picture to keep in mind, John Thøgersen, a professor at Aarhus University whose research focuses on consumer behavior and sustainability, tells me. 

This interview has been lightly edited for length and clarity.

During Climate Week, Google hosted a panel about how to tackle “lifestyle emissions.” I’ve seen promotions for low-carbon liquor and all kinds of other products that are supposed to reduce consumers’ greenhouse gas emissions. The big question I have is, how important is consumer behavior in reaching global climate goals? How big of an impact can I, as a consumer, have in purchasing something because it’s supposed to be better for the environment?

I think there’s common agreement now that it is actually quite important. The most recent reports from the Intergovernmental Panel on Climate Change increasingly speak about consumers. Private consumers are assumed to be about 60 percent of final consumption, which is pretty big.

Now, in terms of consumer behavior, the biggest question is how to influence it. And to what extent could you say that this responsibility is individual versus collective? 

Some people will say that modern consumers live in a way that is mostly locked into a certain lifestyle. It gives them relatively little wiggle room for improving the sustainability of the lifestyle, which points at collective solutions rather than individual solutions.

Collective solutions would be, for instance, public transport rather than individual transport. It’s very clear that people only use public transport if it’s convenient and frequent. Another reason they might use public transport could be that they are not allowed to use cars, like if some cities have car-free zones. You could imagine Manhattan being completely car-free so that people would need to use bicycles and the subway or other public transport. 

Another thing I’m seeing brands start to do, including Amazon and Apple recently, is purchase enough renewable energy to match consumers’ energy use for some of their devices. How impactful is that?

The good thing about them doing this is that it would give an incentive to the company to actually try to reduce the energy use of their products, which I think is more important.

I think that’s an interesting point: who has the responsibility for the electricity consumption in the use phase? The better solution is to, you know, roll out renewable energy in the whole country.

Even for me, it can be difficult to discern what’s impactful versus what might just be marketing to get me to buy something. Do you have any advice for avoiding greenwashing? 

Look for public advice from NGOs and public organizations. My advice to both producers and consumers is to use third-party eco labels and certification so that the claims are backed.

What are some of the most impactful things you can do as a consumer?

One of the things that is strongly voiced in this discussion right now is the importance of focusing on the things that really matter. Those that really give bang for the buck. 

There’s now a lot of research that points at three areas of consumption that stand for 75 percent of the total impact: that’s food; transportation; and energy consumption in our homes. In each of these three areas, it’s possible to point at certain things, certain behaviors, that are especially impactful that people could change. And it’s not always what you think.

By far, the most climate unfriendly foods are beef and lamb. Cows and sheep, in addition to the CO2 emissions from production, also burp methane gas into the atmosphere. So, of course, lots of people know that we should eat less meat. Vegans would say we should go vegan. But really, we should drop beef and lamb. It’s okay if people move from beef and lamb to eat pork and chicken. That’s a huge jump in the food climate footprint. Whereas the difference between a diet that includes chicken and pork but no beef and lamb and a vegan diet is actually quite small. 

You can do a lot with moving to more energy-efficient appliances and so on. But by far, the most you can do is make sure that the energy that comes into the home is from renewables. 

What I’m really saying is that consumption is important. But we cannot individualize the responsibility for sustainable consumption; it’s mostly a collective responsibility. So politicians need to create the frame that makes the right behavior the easy behavior.