(October was again a global temperature record setter. Image source: NASA.)
NASA’s monthly global temperature analysis is in and the results are once again record-making. For according to NASA’s global monitor, world temperatures were 0.76 degrees Celsius above the Earth average for the mid 20th Century.
This high temperature departure ties 2005 for hottest in NASA’s 136 year record. A temperature level that global ice core data points toward being hotter than at any time in the past 130,000 years. A record hot month in a string of record hot months for 2014. A resurgence to record high marks amidst an unprecedented spate of rising temperatures that has lasted now for more than a century running.
(Global temperatures have risen by more than 1 degree C above their low mark at the start of the 20th Century. It is a human-driven pace of warming 15-20 times faster than at the end of the last ice age. Image source: NASA)
Polar Amplification Again Prominent
As in recent months, hottest temperatures were again focused near the poles. The northern polar region in particular observed much hotter than normal readings with a very large zone experiencing +2 to +5.5 degrees C above average temperatures for the entire month. East Antarctica also saw much warmer than normal temperatures with monthly averages spiking from +2 C to more than 4 C above the 20th Century average.
Overall, much of the world showed hotter than normal temperatures with cooler than normal readings confined to sections of the Southern Ocean and Eastern Europe. Small and isolated pockets of cooler than normal readings were found in diminutive oceanic zones. Meanwhile, the rest of the world experienced warmer than normal to much warmer than normal readings.
(Zonal temperature departures by latitude. Image source: NASA)
Zonal readings also showed very strong polar amplification in the Northern Hemisphere with surface temperatures averaging at 2.6 degrees Celsius above normal in the region above 75 degrees North Latitude. A spike in temperature to +1.3 C above average was also observed in the region of 80 degrees South Latitude.
The Southern Ocean again appears to be the primary zonal heat sink as the only region showing below average temperatures in the range of -0.38 C below average. As we have seen in previous analysis, this region is currently the principle atmosphere-to-ocean heat transfer band. Ocean heat uptake in this region has been shown through recent studies to have resulted in very rapid warming of the top 700 meters of Southern Hemisphere ocean waters. It has also played a role in the more rapid glacial destabilization observed among Antarctica’s increasingly fragile ice sheets and ice shelves.
Polar Amplification Sees Late Fall Vortex Disruption, Severe Dipole Anomalies
Northern Hemisphere polar amplification is a primary contributor to the polar vortex disruptions and extreme Jet Stream distension we’ve seen since about 2005. Current conditions also indicate an extraordinary dipole again developing with heat pooling in the Arctic near Alaska and in the maritime zone between the Kara Sea and Greenland. Already in November, this has caused an extreme meridonal avection of polar cold air over the continents even as warm air drives north toward the pole over Atlantic and Pacific Ocean regions.
(Warm air invasion of the Arctic forcing temperatures to 1.9 C above average drives polar air over Central Asia and Eastern North America on November 19 of 2014. Such displacements of cold air during Northern Hemisphere winter are directly tied to global-warming related polar amplification. Image source: GFS/University of Maine)
2014 Close to Hottest On Record
Currently, NASA’s global temperature average for the first ten months of 2014 puts the year at 0.664 C above the global average. 2010, the previous hottest year on record, stood between 0.66 and 0.67 degrees hotter than the 20th Century average. So we are now in record-making territory for 2014. Any further months with average temperatures above 0.67 C would continue to cement 2014 as a new record holder.
In any case, the excessive heat for 2014 is at least likely to place it among the top 1-4 hottest years even if November and December show less extreme warm temperature departures. An extraordinary degree of warmth for a year in which official El Nino status has yet to be declared.
With global political leaders retaining an overall laissez faire attitude to positive action on climate change and with powerful fossil fuel interests gaining power in the US Congress (Republicans), it is unfortunately very likely that ongoing massive greenhouse gas emissions in the range of 50 billion tons of CO2 equivalent each year will continue to add more heat to the world’s oceans, atmosphere, and glaciers. As time moves forward, this will vastly increase the risk of catastrophic weather and geophysical change events. We see such events now in Brazil, California and across an expanding range of regions. But these early outliers are mild compared to the potential extremity of events as time moves forward and catastrophic emission rates increase.
As with other brands of risk, including financial risk, the world’s current economic and political leaders have shown a terrible ineptitude in working to prevent catastrophic and destabilizing loss. One hopes that political and economic leaders will wise up. But, currently, there is very little to indicate that urgently needed changes will be forthcoming.
(Note edited to include the Eemian, which is probably still hotter than this monthly average by about 0.8 to 0.9 C at peak warming)