Four average-size men running will release more carbon dioxide (CO2) than they would if they were all riding together in a hybrid car for the same distance. This does not hold true for average-size women because of their statistically lower body mass. This also does not necessarily mean that hybrid cars are always the more environmentally friendly choice. For instance, this calculation does not take into consideration the total pollution created when building the car or refining the gasoline for use in the car — or for that matter, the fact that humans emit CO2 constantly, whereas cars can be turned off.
More facts about carbon emissions:
- In the mid-1990s, every person on the planet was, on average, responsible for at least one ton of carbon emissions a year — that's about twice what the oceans and forests can absorb.
- Carbon emissions for food transport are high — food in the United States travels an average of 1,500 miles (2,414 km) before it's eaten — but closer is not always better. For instance, it's better, environmentally speaking, to buy certain foods that are shipped — not flown or driven — than those that are driven a great distance because carbon emissions from ships are much lower than those from trucks.
- Indonesia and Brazil are responsible for about 10 percent of the world's total carbon emissions simply because of the rapid deforestation of their rainforests. The only two countries responsible for more carbon emissions are the U.S. and China.