As 2015 tops 5-yr record, El Niño may push 2016 even hotter
Meteorologist/Science Writer
Thursday, November 26, 2015, 3:37 PM - As 2015 ticks along to become the hottest year on record, the latest reports from the World Meteorological Organization revealing facts that are "bad news for the planet."
According to the World Meteorological Organization, not only do they agree with NOAA, NASA and other agencies around the world that 2015 will rank as the new hottest year on record, but their five-year analysis report released on Wednesday shows the period of 2011-2015 was the warmest such period on record.
The average global temperature for that five-year period, at least up to the end of September 2015, sat at 0.57oC above the WMO standard 1961-1990 average, exceeding the 2006-2010 period by 0.06oC.
This, according to the report "is consistent with a continued sustained warming trend which has been apparent in global data since the mid-1970s."
What's shaping up for 2015?
"The state of the global climate in 2015 will make history as for a number of reasons," WMO Secretary-General Michel Jarraud said in a statement. "Levels of greenhouse gases in the atmosphere reached new highs and in the Northern hemisphere spring 2015 the three-month global average concentration of CO2 crossed the 400 parts per million barrier for the first time. 2015 is likely to be the hottest year on record, with ocean surface temperatures at the highest level since measurements began."
"It is probable that the 1oC Celsius threshold will be crossed," Mr Jarraud added. "This is all bad news for the planet."
According to the WMO:
A preliminary estimate based on data from January to October shows that the global average surface temperature for 2015 so far was around 0.73 °C above the 1961-1990 average of 14.0°C and approximately 1°C above the pre-industrial 1880-1899 period.
Temperature records from the Met Office (grey), NOOA (orange) and NASA (blue) show rising global temperatures over the decades, with where 2015 is headed for by the end of the year. Credit: Met Office Hadley Centre
Why a five-year report matters
Reading a list of the hottest years on record is a good example of how weather changes from year to year. As of now, even if El Niño beings to weaken through the rest of the year, 2015 still destined to take over the top spot on that list, only one year after 2014 set a new record. Going further down the list, it's not quite as consistent. 2010 occupies the number 3 spot on NOAA's list, followed by 2005 in 4th, and then 2013 comes in at 5th place.
Looking at these yearly records is important, mainly in seeing how the weather events of the year affected its overall ranking. When you're interested in trends, though, such as tracking the progress of anthropogenic global warming, it's more valuable to take longer-term averages of these temperatures. This eliminates the little year-to-year wiggles in the data, and gives a better view at how things are shaping up for the planet. At the same time, the average you work with should still be on a short enough time-scale to give us a chance to act on any alarming trends that are spotted.
That's what goes into the WMO five-year analysis report.
What other benefits does this longer-look have? For one, it allows climate scientists to examine extreme events during the periods, to put them into a larger context.
According to this report:
Scientific assessments have found that many extreme events in the 2011-15 period, especially those relating to extreme high temperatures, have had their probabilities substantially increased as a result of anthropogenic climate change – by a factor of 10 or more in some cases – with more than half the events scientifically assessed showing an anthropogenic climate change signal of some description in their risk.
Extreme temperature events identified by the report as those with the strongest influence from climate change, with the probability of their occurrence increased by a factor of at least 10 - record heat in the United States in 2012 and in Australia in 2013 (for both seasonal and annual records), hot summers in 2013 for eastern Asia and western Europe, the heatwave in Argentina during December 2013, the heatwaves experience by Australia in spring and autumn 2014 and Europe's record annual temperatures from 2014.
2016 even hotter?
While higher concentrations of carbon dioxide in our atmosphere are having a strong influence on the overall trend of rising temperatures, one factor for 2015's impending record heat is the strong El Niño currently dominating in the equatorial Pacific Ocean.
As much as this pattern of heat in the Pacific is affecting global temperatures this year, the WMO expects that it's influence will be even stronger on next year's records.
"Whilst a strong El Niño event is currently in progress, the impact of El Niño (and La Niña) on global annual mean temperatures is typically strongest in the second calendar year of the event," the WMO report says "and hence the year whose annual mean temperature is likely to be most strongly influenced by the current El Niño is 2016 rather than 2015."
Does that mean a third "hottest year" in a row? Possibly.
When the last El Niño of comparable strength developed in 1997, that year's global temperatures ended up ranked as the highest on record at the time, according to NOAA, at 0.51oC above the 20th century average. 1997 currently ranks only 16th on NOAA's list of hottest years on record, though.
It was 1998, the second year of that super El Niño, that was the hotter of the two overall. It took over from 1997 as the hottest year on record, at 0.63oC above the 20th century average, it kept that ranking on NOAA's list until 2005, and it still ranks as 5th hottest year overall.
Given that NOAA's Climate Prediction Center forecast for this year's El Niño has it persisting until late spring or early summer, unless weather patterns in 2016 take a very drastic turn towards cooling off, the year could follow the same pattern we saw 18 years ago.
Sources: WMO | WMO (docx) | NOAA | NOAA CPC
Watch Below: NASA JPL's comparison of El Niño 1997/98 with the current El Niño pattern, through November 18, shows off the similarities and differences between these two monsters.
