The first half of 2016 has blown away temperature records, capped off by a record hot June, once again bumping up the odds that 2016 will be the hottest year on record globally, according to data released on Tuesday.
The monthly numbers from NASA and the National Oceanic and Atmospheric Administration puts the planet on track to surpass 2015 as the hottest on record.
“2016 has really blown that out of the water,” Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies, said.
While 2016 has gotten a boost from an exceptionally strong El Nino, the record temps are mostly the result of the excess heat that has built up in Earth’s atmosphere due to accumulating greenhouse gases. That heat is raising global sea levels, disrupting ecosystems and leading to more extreme weather events, Climate Central reported.
Every month this year has been record warm globally. Several months early in the year were among the first ever recorded to exceed 1°C above average.
With the demise of El Nino, those temperature departures have dropped slightly, but are still at record-high levels. June was 0.90°C above the 20th-century average according to NOAA and 0.79°C above the 1951-80 average, according to NASA.
In NOAA’s records, that makes an unprecedented 14 consecutive record-hot months. While that streak will eventually end, Deke Arndt, the head of the climate monitoring division at NOAA’s National Centers for Environmental Information, said the long-term warming trend is still clear.
"It's important to keep perspective here. Even if we aren't setting records, we are in a neighborhood beyond anything we had seen before early 2015," Arndt said in an email. "We've left the 20th century far behind. This is a big deal."
With June’s record heat, the year-to-date is 1.05°C above the 20th-century average, according to NOAA, and 1.09°C above the 1951-80 average according to NASA.
The temperatures “are so in excess of any first part of a year that we’ve seen”, Schmidt said.
Nations have agreed to a goal of keeping warming under 2°C above temperatures from preindustrial times—before manmade greenhouse gases began building up in the atmosphere—by the end of the century.
To put current global temperatures into the perspective of that framework, Climate Central has been reanalyzing the NASA and NOAA data. The two datasets are averaged and then compared to the average from 1881-1910, closer to the preindustrial era.
Through June, 2016 was 1.34°C above the average for that period. Whether 2016 ultimately bests 2015 depends on how the second half of year goes. Forecasts have backed off predictions of a La Nina this fall; La Nina tends to cool global temperatures.
The significant lead that 2016 has makes the odds good that the year will end up the warmest, though there is no guarantee.
Regardless of where 2016 falls, the long-term trend of warming is clear, and it has tipped the odds in favor of record heat: Of the 15 warmest years on record, 14 have occurred in the 21st century.
"This year will be one of the warmest on record. Whether it slips to nominally above or nominally below 2015, that may depend on some climate variability factors like the strength of the La Nina," Arndt said.
"But it will share with 2015 the distinction of being, comfortably, the two warmest years on record and warmer, comfortably than any year we've measured in modern times."
