According to NOAA, December continued the trend to more moderate increases in temperature, even as 2016 went into the record books as the warmest ever.
The decrease of departures from normal between January and December of 2016 can be attributed to the transition from strong El Niño to modest La Niña conditions in the tropical Pacific Ocean.
At the same time, atmospheric CO2, one of the primary causes of the temperature increase, is setting new seasonal high marks and approaching new all-time records.
December 2016 By The Numbers
For a change, December’s temperature did not set a record in any of the nine categories into which NOAA breaks it down: Global land, sea, and combined; southern hemisphere land, sea, and combined; northern hemisphere land, sea, and combined.
Averaged over the entire Earth (land and sea combined), the temperature was 13.99° C (55.42° F). This was the third highest December average in the 137 years of records.
Still, it was 0.33 C (0.60 F) below the warmest December of 2015. This is attributable to the El Niño/La Niña cycle and is not an indication that the Earth is descending into an ice age. It also demonstrates that comparisons should be made over longer — and comparable — time periods.
Where Was It Hot? Where Was It Not?
In December 2016, a swath of below-average temperatures reached from northern Siberia southwest through the Middle East, eastern Europe and extending into northeast Africa. Another cold area covered southwestern Canada and northwestern US.
Both of these northern hemisphere cold areas bear watching as they contrast with the powerful warming in the Arctic. The Danish Meteorological Institute has been measuring temperatures departing by an average of 10 C (18 F) north of 80° latitude this winter.
In recent years, the jet stream has frequently dipped southward and the polar vortex has affected weather over the northern hemisphere continents.
This is subjective circumstantial observation, and awaits enough data on which to base any prediction about future climate. However, it is important because changes in the general circulation would exacerbate the effects of global warming.
In addition to the land areas noted above, the tropical Pacific Ocean was cold under the influence of La Niña, and parts of the South Pacific, South Atlantic, and South Indian Oceans were colder than normal.
Elsewhere, warmth prevailed. Most of South America, Africa, Asia, and Australia were warm. Most of Europe was warm, particularly Scandinavia. Nearly the entire North Atlantic, North Indian, and subtropical North Pacific Oceans were warmer than normal.
Full Year 2016 Sets Records In Most Categories
Overall, 2016 was 0.04 C (0.07 F) warmer than 2015.
2016 led in all categories except northern hemisphere ocean and southern hemisphere land. Even extrapolating the small difference from last year to this year gives a warming of 1 C (1.8 F) per 50 years.
A more meaningful extrapolation would be from one El Niño to the next comparable one. 1998 and 2016 were almost identical in the profile of their El Niño/La Niña cycles. During these 18 years, the average global temperature increased by 0.30 C (0.54 F). This extrapolates to a warming of 1 C in 60 years.
Where Was 2016 Record Warm?
2016 produced record warm temperatures over a large part of the Earth. This is even more impressive considering that the bar set by 2015 was high. The following places set new records for warmth:
- The southern half of Africa
- The northern third of South America
- All of Alaska
- All of Pakistan and Afghanistan, as well as parts of adjacent countries
- All of Malaysia and Indonesia, extending over the adjacent waters to northern Australia and southern Asia
- Most of the subtropical South Pacific Ocean
- Most of the Gulf of Mexico, Caribbean Sea, and the adjacent Atlantic Ocean
- The western North Atlantic Ocean
This is an impressive list; 2016 was a very hot year. Nevertheless, there was one place that set a temperature record for cold: A spot east of Drake’s Passage, which separates South America from Antarctica.
Though it didn’t set a record — or even come close — the area that Decoded Science has dubbed the Anti-Blob south of Iceland persisted. This cold water has been a noticeable feature for several years.
Precipitation For 2016
Precipitation varies widely from one month to the next, and single events can skew the data for a long time. In addition, precipitation is less reliably measured than temperature. Snow, for example, can swirl and drift; rainfall can vary by a large amount over a short distance in a thunderstorm and from one side of a mountain to the other.
Climate change, particularly as it affects precipitation, could be critical to the global food supply. If the years-long drought in California were to continue over a decade or more, the Central Valley, which produces a quarter of the country’s food, would be seriously affected.
The most notable departures from normal precipitation in 2016 were:
- Drier than normal in the eastern US
- Wetter than normal from southern Europe to central Asia
- Wetter than normal in southern South America
- The US west coast got some relief from the drought, but above-normal precipitation only fell in the northern part of the region.
Feel The Burn
Atmospheric carbon dioxide has risen by 45% since the start of the industrial revolution. The science of the heat-trapping ability of carbon dioxide in the atmosphere and its anthropogenic cause are accepted by an overwhelming percentage of experts. The global temperature data for the last two years implies that implementation of carbon reductions under the Paris agreement is urgent. Meteorologists have done their job of presenting the science. Will politicians do their job by curbing carbon emissions?