Last month was pretty darn hot as global temperature measures go.
According to NASA, the world’s thermometer averaged 1.14 C warmer than 1880s temperatures or about 0.92 C warmer than NASA’s 20th Century baseline. These readings were the third warmest for January since NASA record keeping began in 1880.
(A record hot world cools a little during January of 2017 relative to 2016. Unfortunately, with La Nina fading and a new El Nino predicted and with atmospheric CO2 measures continuing to climb, more record breaking or near record breaking global heat appears to be on the way. Image source: NASA GISS.)
2016-2017 La Nina — Not Very Cool
For a temperature measure that has consistently been producing ‘hottest months on record’ throughout 2016, the dip back to top 3 during January represents an ephemeral respite. More to the point, the fact that this third hottest ever reading occurred during the cool phase of natural variability called La Nina presents little cause for reassurance.
The Pacific Ocean has merely been drawing in more atmospheric heat on balance, as its periodic cycles dictate, during the months of September 2016 through January 2017. But despite a heat draw-down due to this variable cool ocean phase, the period produced consistent second and third hottest months on record globally. In particular, warming at the poles (and especially in the Arctic) appeared to substantially counter the cooling influence of the weak La Nina.
(With a weak La Nina fading, a weak to moderate El Nino apparently on the way, and with atmospheric greenhouse gasses at record high levels, it appears that 2017 temperatures will range close to the record global warmth that occurred during 2016. Image source: NASA.)
Overall, the average temperature of these five cooler La Nina months was 0.876 C above NASA’s 20th Century average (1.096 C above 1880s). A reading considerably warmer than the 1998 super El Nino year average of 0.63 C above 20th Century baselines (0.85 C above 1880s). An average unsettlingly close to the 0.98 C above baseline (1.2 C above 1880s) measure for 2016 as a whole.
Predicted 2017 El Nino Would Push us Back to Near Record Hot Too Soon
With a La Nina period so greatly exceeding 1998 El Nino averages, we can confidently say at this time that the old cherry previously used by climate change deniers for so many frequent misrepresentations has now been left in the dust and ash of the great global burning of fossil fuels continuing unabated since that time and that this year will push CO2 and CO2e levels to above 410 ppm (peak) and 493 ppm respectively.
(Warm Kelvin Wave now propagating across the Pacific indicates that a weak-to-moderate El Nino may form by Summer of 2017. Such an event, when combined with record levels of atmospheric greenhouse gasses, would tend to keep 2017 temperatures closer to record warm ranges established during 2016. Image source: NOAA.)
For the coming months, we can say with some confidence that global temperatures again appear likely to start rising. NOAA model guidance now points toward a likelihood of a new weak El Nino forming by May or June. An event that will possibly expand into a moderate strength event come the Fall of 2017. Already, a plug of warmer than normal water is propagating from west to east just beneath the Equatorial Pacific’s sea surface. And this warm water is expected to expand off South America and then spread westward along the Equator in a classic El Nino scenario for the coming months.
El Nino forecasts for this time of year can be rather uncertain. However, if NOAA models are correct, the added warmth over so much surface water in the Equatorial Pacific will also tend to push an atmosphere already loaded with an abundance of heat-trapping gasses to again warm.
(NOAA CFSv2 model runs show a moderate El Nino forming by late Summer or early Fall. Image source: NOAA.)
So the La Nina range of 0.95 to 1.15 C above 1880s will tend to tip toward 1.05 to 1.25 C above 1880s during a weak to moderate El Nino event. A range very close to what we recently saw during the record warm year of 2016.
Risks for Heat Related Climate Disruptions to Remain Heightened
So much re-warming so soon on the tails of 2016 is not very good short or medium-term news for the global climate system. It means that issues such as severe droughts and floods, disruption of monsoonal weather patterns, increasingly prevalent wildfires, climate related stresses to crops, global coral bleaching, and immediate melt stresses to polar zones are likely to fail to abate during 2017. The one silver lining being that 2017 is less likely to hit a new record global high temperature mark than 2016 was. But global temperatures hitting so high already at the tail end of three record warm years in a row is little cause for comfort.