Historical events linked to changes in Earth’s temperature

Ozone treaty, wars and Great Depression influenced global warming rate, scientists find

SHRINKING HOLE  The ozone hole over Antarctica reached its largest extent in 2006 (purple and blue indicate depleted ozone) before starting to shrink. The international treaty intended to reduce the ozone hole has had a cooling effect on Earth’s climate, a study finds.

NASA

The Great Depression, World Wars I and II and an international treaty restricting ozone-depleting chemicals each had measurable effects on global temperatures, scientists report November 10 in Nature Geoscience.