For the past 800,000 years, the concentration of atmospheric carbon dioxide varied from 180 parts per million (ppm) to 300 ppm. Continuous measurements made since 1957 showed levels climbing above 300 ppm and concentrations are now above 420 ppm, some 50% greater than pre-industrial levels. Nearly all scientists agree that this is an anomaly caused by humans using fossil energy. Fossil fuel combustion products have added significant amounts of carbon dioxide to the atmosphere, a “greenhouse gas” that traps heat radiated from the warm Earth, warming the atmosphere and causing climate change. The evidence is clear and compelling. No explanation other than human fossil fuel combustion fits the timing and the trend of the data. Nevertheless, so-called “climate skeptics,” who are largely connected to the fossil fuel industry, have introduced artificial uncertainty to bog down policy initiatives and stall climate legislation in endless debates. There is virtually no disagreement among the scientists who are independent from the fossil fuel industry. The anomaly is real, and getting worse. Climate change is undeniable. The uncertainty promoted by the fossil fuel industry is producing delays that will make the eventual solution more expensive and more technically challenging as the climate continues to deteriorate.