Record-breaking March may cinch 2016 as hottest year

Global temperature anomaly map for March 2016, with an average of +1.29^oC above the 20th century average. Credit: NASA GISS

Wednesday, April 20, 2016, 2:00 PM - Only three months into 2016 and even the most conservative estimate of global temperatures is already pushing the entire year to the top of the list of hottest years on record.

Agencies from around the world have weighed in on March 2016, and no matter how you look at it, it was a record-breaker:

• Hottest month of March on the books, at +1.29^oC according to NASA, +1.22^oC according to NOAA and +1.07^oC according to the Japan Meteorological Agency (all measured against the 20th century average)*.
• Hottest month of any month in NOAA and JMA records, with the largest departure from monthly average (February still ranks highest with NASA).
• Hottest year-to-date on record, as January, February and March tally up to +1.23^oC according to NASA, +1.15^oC according to NOAA and +1.01^oC according to the JMA (all, again, vs the 20th century average)*.
• Continues a streak of 9 consecutive months with the highest temperature departures from average in the record books.
• Sustains an 11-month string of record-breaking hottest months, from May 2015 to March 2016, which is the longest such string of broken records in NOAA's 137-year tally of global temperatures.

*Each agency uses slightly different methods of computing their average, which results in different final values, however their overall findings show the same warming trends.

Credit: NOAA NCEI

On top of all of this, with the last three months ranking so high in the temperature records, the odds are already heavily in favour of 2016 taking its place as the newest hottest year on record.

So, simply based on a comparison between each year's January-February-March global temperature average and the final global temperature average at the end of each year, climate scientist Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies (the department that tallies NASA's global temperature records), shows that - even when accounting for uncertainties in the data - 2016 is almost certain to beat out 2015 for top-spot in the record books.

He has good reason to speculate, as well. Taking a glance at 2015, even as early as March of that year it was easy to see how it was going to be the newest hottest year on record, because monthly temperature departures would have needed to come in around 7th warmest on record or colder for 2014 to keep its title as the hottest year (at +0.69^oC above the 20th century average). With the temperature trends seen in recent years and a strong El Niño adding its own (albeit small) contribution to global heat, regressing back that far was highly unlikely.

For 2016, we need only look at the global temperature trends for El Niño years to show that Schmidt is not far off in his speculation.

What is El Niño? | What is La Niña?

Back in 1997, when the last "super" El Nino developed, the year came in as the hottest on record, at +0.42^oC above the 20th century average. During the following year, even as that "strongest El Niño on record" was decaying into a La Niña, temperatures for 1998 soared, with the year coming in at 0.63^oC above the 20th century average. This general trend of having higher global temperatures in the second year of an El Niño event has played out again and again in the records, and in all likelihood, it will play out again this year as well.

Sources: NOAA | NASA | JMA

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