globally averaged thermometers show two periods of warming since 1900: a half-degree from natural causes in the first half of the 20th century, before there was an increase in industrial carbon dioxide that was enough to produce it, and another half-degree in the last quarter of the century.
globally averaged thermometers show two periods of warming since 1900: a half-degree from natural causes in the first half of the 20th century, before there was an increase in industrial carbon dioxide that was enough to produce it, and another half-degree in the last quarter of the century.
20th century:6
the average global temperature on earth has increased by about 0.8° celsius (1.4° fahrenheit) since 1880; two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20 °c per decade.