New research has convincingly quantified how much the Earth has warmed over the past 56 years. Human activities utilize fossil fuels for many beneficial purposes but have an undesirable side effect of adding carbon dioxide to the atmosphere at ever-increasing rates. That increase – of over 40%, with most since 1980 – traps heat in the Earth’s system, warming the entire planet. But how fast is the Earth warming and how much will it warm in the future? Those are the critical questions we need to answer if we are going to make smart decisions on how to handle this issue.