While it is true that one month or one year of warmer weather does not prove the existence of global warming, however 30 consecutive years of above average temperatures offer compelling evidence of climate change. It has been 3 decades since we have seen monthly global surface temperatures that have fallen below the mean. The last time be saw monthly temperatures that fell below the mean was February 1985. Thirty consecutive years of monthly temperature anomalies are hard to discount.
There is a lot of variability in weather, but climate refers to a long term pattern. Weather can be measured by day or by month or even by year, but according to the World Meteorological Organization (WMO) to scientifically demonstrate climate change requires a much longer period, 30 years to be exact. This is what makes the mark reached in February so important. Together the three decades of global temperatures constitute the new normal of warmer average weather.
If we look at global average temperatures we have to go back to 1976 to find a year when temperatures fell below the mean. Similarly, average monthly ocean temperatures have been above the mean for 38 consecutive years.
The primary cause of these warming temperatures is cheap oil and in 1976 the price of a barrel of oil was $12.37.
Related
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James Hansen’s 2012 Research Linking Global Warming and Extreme Weather
In the US 2012 is The Hottest Most Extreme Year in Recorded History
Globally 2012 is One of the Hottest Years on Record
