evidence: The conclusion rests on basic physics known since the 19th century, when physical scientists first recognized that carbon dioxide, then a recently discovered gas, could act as a sort of greenhouse, preventing heat introduced by the Sun from escaping back as thermal radiation into space—the "greenhouse effect." The heat trapped by carbon dioxide warms our oceans and atmosphere. This effect is what enables life on this planet, keeping Earth at a livable global temperature. But changes in the concentrations of these gases change the amount of heat that remains here. [...] Ice cores tell us that the atmosphere’s carbon dioxide levels have stayed between 170 and 300 parts per million for the last 800,000 years, and any shifts took millennia to happen. But since about 1750, the start of the Industrial age, the level has ascended from 280 to more than 400 parts per million. The rise in carbon dioxide matches well with the curve of known human emissions. And these two curves match very well with the increase in temperature. The overwhelming evidence shows that carbon dioxide emissions are the dominant factor driving climate change.