evidence: Scientists agree that global warming is caused mainly by human activity. Specifically, the evidence shows that certain heat-trapping gases, such as carbon dioxide, are warming the world—and that we release those gases when we burn fossil fuels like coal, oil, and gas. [...] Carbon dioxide (CO2) is the heat-trapping gas in our atmosphere responsible for most of the warming measured over the past several decades. It’s released during cement manufacturing and when coal, gas, and oil are burned—something humans started doing a great deal of during the Industrial Revolution through to today. [...] We know that CO2 warms the world, that CO2 concentrations are at record-breaking levels, and that global temperatures are rising. But how do we know for certain that humans are the cause?