Liberal Myth
Today’s global warming is unprecedented.
The Facts
The earth’s average temperature has increased over the last 30 years, and many point to this as evidence of a dangerous human-induced warming. But temperatures have risen and fallen many times before that.
- The Medieval Warm Period (c. 1100-1450) and earlier periods were likely as warm or warmer than the present.
- The earth was cooling as recently as the period from the 1940s to the 1970s, giving rise to fears of a coming ice age, until temperatures began to increase in the mid-1970s up through the present day.
While it is likely that mankind’s activities have made a contribution to warming, current temperatures are within the range of natural variability.
Related Heritage research
- Ben Lieberman, “Frequently Asked Questions About Global Warming,” March 21, 2007
- Ben Lieberman, “Don’t Rush To Judgment on U.N.’s IPCC Global Warming Summary,” February 7, 2007
