2015 was hot. Globally, it was the warmest year on record by a large margin. But, there was an El Nino event in the Pacific which probably boosted temperatures slightly (by up to 0.1°C).
So, what can we expect for 2016? Using an analogy of similar El Nino events we can make some suggestions.
04/04/16 – updated data to February 2016
The figure below shows ENSO anomalies (defined using Nino3.4), and variations in global surface air temperature and lower tropospheric temperatures (TLT) during 1982-3, 1997-8 and 2015-6. The evolution of ENSO has been very similar in these three periods, peaking between years, and the expectation is for a decline in ENSO for 2016 also. Both 1983 and 1998 ended in La Nina conditions meaning the annual ENSO index was lower than 1982 and 1997 respectively.
Naïvely, this might suggest that 2016 would be cooler than 2015.
But, what is interesting is that the largest anomalies in global temperature for both the surface and lower troposphere occur later than the largest ENSO anomalies, peaking in boreal spring and summer after the El Nino event. Because of this lagged response to El Nino, 1998 was much warmer than 1997 in both surface and satellite datasets, and the same is true for 1982-3.
As an aside – note the global surface temperature increases between 1982, 1997 and 2015 – a clear warming signal of around 0.2°C per decade for similar ENSO states.
But what about the satellite data? The response in the troposphere was larger than at the surface in 1997-8. This is also true to a lesser extent in 1982-3, but the eruption of El Chichon in April 1982 complicates matters. It will certainly be interesting to watch how TLT changes during 2016.
So, if 2016 follows a similar pattern to 1983 and 1998, then it will be much warmer at the surface than the already record year of 2015. The Met Office 2016 annual forecast seems to suggest this, expecting a similar (but perhaps slightly smaller) jump to that seen from 1982 to 1983 and from 1997 to 1998.
Any other predictions?