In “The Case for Climate Change Alarmism
,” Forbes.com contributor William Pentland earlier this week called our attention to a paper released by researchers at the Sandia National Laboratory asserting that a large range of uncertainties regarding the potential effects of global warming justifies long-term and presumably far-reaching political action. The Sandia paper, however, gives undue weight to far-fetched climate scares while largely ignoring the real-world evidence of the many benefits of a moderately warming climate. By properly considering all factors, negative and positive, it is hard to make a case for climate change alarmism.
The first principle we need to keep in mind regarding climate change alarmism is context. While it is true that global temperatures have risen somewhat during the past 100-plus years since the Little Ice Age ended, there was little room for temperatures to go at the time but up. The Little Ice Age, lasting from approximately 1300-1900 A.D., brought the planet’s coldest extended temperatures during the last 10,000 years. Saying that temperatures have risen by 1 degree or so since the end of the Little Ice Age tells us essentially nothing in the long-term temperature context because the arbitrary baseline of the Little Ice Age was an exceptionally cold climate anomaly.
Keeping this long-term temperature context in mind, global warming alarmists frequently assert that a given month, year, or decade was “the hottest in recorded history,” but that statement only holds true because alarmists conveniently define “recorded history” as the past 130 years or so since the depths of the Little Ice Age. Alarmists justify this convenient definition of “recorded history” based on the establishment of a relatively global system of weather and temperature stations approximately 130 years ago. Fair enough, but proxy climate data from a variety of sources, including ice cores drilled in the Greenland and Antarctic ice sheets, demonstrate that global temperatures were warmer than today for most of the past 10,000 years. Human civilization first developed, and thereafter thrived, during climate conditions warmer than today. Today’s temperatures, in a more appropriate long-term context, are unusually cold, not hot.