But what is a carbon footprint, exactly? And how is it related to the climate crisis? Here are some answers.What is a carbon footprint?A carbon footprint is basically the total amount of greenhouse gas emissions that anything — a person, organization, event or product — has produced. Greenhouse gases are the gases in the atmosphere that produce the “greenhouse effect” and contribute to global warming and climate change. So your carbon footprint a way to measure the environmental impact your lifestyle has. For example, if you drive to work every day your carbon footprint might be bigger than someone who relies on public transport because you’re emitting more greenhouse gas. Read MoreHow is it calculated?It works by summing up the emissions from all your activities — everything from what you eat to what setting you wash your clothes with.It’s all measured in CO2e, which stands for carbon dioxide equivalent and is a standard unit for measuring carbon footprints. It essentially takes any quantity or type of greenhouse gas and expresses it in the amount of CO2 that would have the equivalent global warming impact. It just allows us to easily compare impacts across different gases. How do you know what your carbon footprint is?There are a number of online calculators that can help you figure out your carbon footprint, including one by The Nature Conservancy and another from the US Environmental Protection Agency.Once you know your carbon footprint, and what part of your lifestyle contributes the most to it, you can then find ways to lessen your impact.Carbon footprint figures that might surprise youMeat products have bigger carbon footprints per calorie than grains or vegetables. That’s because animals like cattle, sheep and goats produce a lot of methane gas. In 2016, they produced 170 million metric tons in CO2e of methane, according to a carbon footprint fact sheet compiled by the Center for Sustainable Systems at the University of Michigan. And yes, all that ends up in the atmosphere.Meat isn’t the only problem, the center says. Dairy products like cheese and yogurt contribute almost 19% of greenhouse gases emitted — even worse than poultry, seafood and eggs, which only contribute 14% of greenhouse gases. Vegetables, meanwhile, contribute a mere 4.9%. The center found that on average, one American household emits 8.1 metric tons of CO2e each year through food consumption alone. Yes, that’s TONS. The production of food accounts for 83% of emissions, and its transportation accounts for 11%. And the fact sheet points out that if you follow the speed limit, not only will you not get a ticket, you’ll also improve your fuel economy and, by extension, shrink your carbon footprint through greater fuel efficiency. You’ll also be better off — literally. The center found that when driving 50 mph or more, every 5 mph increase is equivalent to paying between 20 and 40 cents more per gallon.Speaking of your commute: Transportation is one of the biggest producers of CO2, only behind electricity generation, according to environmental advocacy group NuEnergy.Reducing waste, surprise surprise, actually makes a difference. For every 10% of waste reduction, you can avoid 1,200 pounds of CO2e, according to the Center for Sustainable Systems. And that’s not just recycling, that’s also simply by buying products with less packaging and refusing plastic bags at the grocery store.NuEnergy says that fossil fuels and coal are the source of 67% of generated electricity. If you’re trying to reduce your carbon footprint, think about that next time you leave the lights on. Corperations, unsurprisingly, have the biggest carbon footprints of all. Just 100 companies are responsible for more than 70% of the world’s emissions, according to a 2017 report from the nonprofit CDP in collaboration with the Climate Accountability Institute.