Banner image above: The “Hockey Stick” [Mann, Bradley, & Hughes, 1999]
Global temperature anomalies averaged and adjusted to early industrial baseline (1881-1910) NASA GISS, NOAA NCEL, ESRL
Above is a combined plot of overall global temperature change and atmospheric CO2 concentration over the past 137 years—since coal and oil burning began.
The CO2 scale (right) is the atmospheric concentration in parts-per-million (air), but has been scaled for comparison to plot on the same ordinate as the temperature anomaly.
These plots are referred to as the “hockey stick” owing to the long level “handle” on the left (extending back centuries) and the steep rise on the right which began suddenly around 1950.
2. An increase in CO2 from a known cause—fossil fuel burning—increases global temperature through a known mechanism—the greenhouse gas effect .
 Discovered by the Swedish chemist and Nobel Prize winner Svante Arrehnius in 1896.]
James Hansen, Climate Change in a Nutshell, 2018