Greenhouse gases up; Temperature stable
The uncertainty of science: Even as the Earth’s climate temperature has remained essentially unchanged for the past two decades, the rate of increase in greenhouse gases in 2013 hit its highest number in thirty years.
This Nature article is interesting in two ways. First, it actually breaks with the tradition of the past two decades and notes the gigantic uncertainties that exist in climate science.
The question remains, however, of why the rise in global mean temperatures near the surface has apparently slowed, after a series of exceptionally warm years in the 1990s.
To have mentioned an inconvenient fact like this, casting doubt on the theory of human-caused global warming, has been forbidden for decades in major journals like Nature. That the article does mention it shows that the inconvenient facts have become too obvious to ignore.
The second way the article is interesting is its repeated attempt to make believe that new theories, based on this very incomplete and contradictory data set, can explain the mystery.
Scientists have suggested a number of possible explanations for the global warming pause. According to the latest hypothesis, regularly occurring changes in circulation patterns in the Atlantic and Southern Ocean may have caused an increased volume of relatively warm water to sink to the depth of the ocean, thus reducing the amount of ocean heat escaping to the atmosphere.
The sad fact is that there are now dozens of theories to explain the long pause in global warming, none of which are convincing. The uncertainties continue to rule!
Similarly, the article also makes this naive statement:
Atmospheric methane, the second most important long-lived greenhouse gas, also reached a new high of about 1,824 parts per billion last year, mostly due to increased emissions from cattle breeding, rice farming, fossil fuel mining, landfills and biomass burning. [emphasis mine]
The certainty expressed here about the sources of methane increase in the atmosphere is misplaced. We don’t really know all the sources of the increase in methane in the atmosphere. Recent data instead suggests it could have many natural sources having nothing to do with human activities.
The bottom line remains: The knowledge we have of the Earth’s atmosphere and climate remains very incomplete and preliminary. Any theories about its nature and operation must be taken with a very large measure of skepticism. Any particular theory might be right, but it is just as likely that future research will very easily prove it wrong.
It would be nice if the journalists at Nature would take this advice.