You Think 2012 Is Hot? Wait Until 2013. Barring a volcanic eruption, next year will set records. But don’t blame El Niño.
Meanwhile, El Niño conditions are forecast to develop in the tropical Pacific Ocean, warming up ocean surface temperatures. Some observers have predicted that this will lead to record-breaking global temperatures next year.
If El Niño does arrive and temperature records are broken, there will inevitably be much discussion of the causes of the warming. So now is a good time to sort signal from noise in the global temperature records.
We have independent measurements describing all three that we can easily correlate to global temperature changes. This shows, for example, that during a solar maximum, the globe is about 0.1 C warmer than during a solar minimum, but also that solar activity has contributed nothing to the warming trend of the past 30 years. In fact, it has acted to reduce it, but the effect is so small that the hottest year on record, 2010, was near the end of the deepest solar minimum since satellite measurements began in the 1970s.
The analysis further shows that global temperature typically reaches a maximum about four months after El Niño conditions peak, and is correspondingly colder after La Niña. La Niña episodes in 2008 and 2011 have cooled the past few years, masking the warming trend. But while 2011 was cool in the context of the previous 10 years, it was the hottest La Niña year on record.
It is straightforward to remove the effects of the solar and El Niño cycles from the data, just as unemployment figures routinely have seasonal effects removed. Once this is done, and regardless of the global temperature dataset used, the result is always a steady warming trend that has been no slower in the past decade than it was in the previous two—and which, incidentally, agrees with what is predicted by the Intergovernmental Panel on Climate Change.
Now solar activity is on the way back up, and it is only a matter of time before the next El Niño event comes along. In fact, predictions by the U.S. National Oceanic and Atmospheric Administration suggest that El Niño conditions are likely to arrive any time now. These two factors, combined with the ongoing warming trend, make it likely that a global temperature record will be set next year—unless a major volcano erupts.
So if global warming of the past decades was due to El Niño or another mechanism involving heat from the ocean, the ocean would have lost heat. But the heat content has gone up, not down. And it is well understood why: because we created a radiation imbalance by adding greenhouse gases to our atmosphere.
The signal of global warming caused by humans is very clear, despite attempts by certain parties to drown it out with a lot of noise.