The recent hot U.S. summer has prompted many climate doomsday scientists to claim that human CO2 is causing extreme climate change, as represented by high temperatures and severe weather events - however, the actual empirical evidence does not support the alarmist claims
(click on image to enlarge)
Indeed, for many parts of the U.S. there has been a long, hot and dry summer. In other parts of the world though, very cold and very wet weather has ruled - Alaska, London and Australia have had much colder weather than normal, for example.
Despite global temperatures being somewhat average when compared to the last 15 years, that has not stopped the usual climate doomsday alarmists to claim that human CO2 emissions are causing new temperature extremes and severe weather events, both in the winter and summer months.
As the adjacent plot of NOAA data reveals, the claim that rising atmospheric CO2 levels are causing extremes and and more frequent severe weather events just does not hold any water, at least for the U.S. To summarize the key points of the chart:
1. CO2 emissions started their rapid increase during the 1950s
2. The supposed doomsday scientists' "safe level" of CO2, 350 ppm, was not reached until 1988
3. The majority of extreme, record setting temperature events, hot and cold, took place prior to the 1950s
4. The peak of record setting 24-hour snowfall events happened during both the 1960s and the 1990s
5. The peak of record setting 24-hour rainfall events happened during the 1990s
6. The 1990s and the 1960s did not produce many max/min temperature records, which alarmists state are the actual cause of those severe weather record setting incidents
7. The 1930s easily had the most states establishing their maximum and minimum temperature records, yet this extreme temperature climate failed to produce the predicted severe record setting rainfall and snowfall incidents
8. The decade of the 2000s, with the highest atmospheric CO2 levels ever, failed to produce any noteworthy temperature records but one, and severe weather records plummeted from the pace established during 1990s
9. So far, the 2010 decade looks to be a piker when viewed in the context of temperature and severe weather events
10. CO2 levels above the "safe" 350 level appear to be fairly 'safe' for U.S. residents. There were more extreme climate/weather records produced prior to 350 being reached (Note: all rain/snow records during the 1980s took place prior to 1988 - the magically dangerous 350 ppm year)
Conclusion: The empirical evidence of extreme climate change being a result of rising atmospheric CO2 levels is essentially flimsy at best. Although global warming has been happening since the Little Ice Age, its impact on extreme temperatures and severe weather incidents has not been substantial over recent decades. In fact, it is highly likely that modern severe weather events really pale to the well documented events that occurred during the 1930s, when CO2 levels were "safe."
Previous severe-weather postings. Additonal severe-weather and modern temperature charts