Third-hottest June puts 2017 on track
to make hat-trick of hottest years
June 2017 was beaten only by June in
2015 and 2016, leaving experts with little hope for limiting warming to 1.5C or
even 2C
The latest figures
cement estimations that warming is now at levels not seen for 115,000 years.
Michael Slezak
Wednesday 19 July 2017 06.12 BST First published on
Wednesday 19 July 2017 05.17 BST
Last month was the third-hottest June on record globally,
temperature data suggest, confirming 2017 will almost certainly make a
hat-trick of annual climate records, with 2015, 2016 and 2017 being the three
hottest years since records began.
The figures also cement estimations that warming is now at
levels not seen for 115,000 years, and leave some experts with little hope for
limiting warming to 1.5C or even 2C.
According to new figures from the US National Oceanic and
Atmospheric Administration (Noaa), June 2017 was the third-hottest June on
record, beaten only by the two preceding Junes in 2015 and 2016.
The Noaa data show combined land and sea-surface
temperatures for June 2017 were 0.82C above the 20th century average, making a
string of 41 consecutive Junes above that average.
June 2016 still holds the record at 0.92C above the 20th
century average, followed by June 2015 which was 0.89C above the baseline.
The data line up closely with Nasa figures released last week,
which are calculated slightly differently, finding the month was the
fourth-hottest on record – with June 1998 also being warmer in their data set.
Based on the Nasa data, climate scientist and director of
Nasa’s Goddard Institute for Space Studies Gavin Schmidt estimated that 2017
was probably going to be the second-warmest year on record after 2016, but
would almost certainly be among the top three hottest years.
The June data see all of the first six months of 2017
sitting among the three warmest months on record, making it the second-hottest
first half of a year on record – again, beaten only by the previous year.
The near-record temperatures continued this year despite the
passing of El Niño, which normally warms the globe, and its opposite – La Niña
– currently suppressing temperatures.
The warming trend is almost certainly caused by greenhouse
gas emissions – mostly the result of burning fossil fuels – with many studies
showing such warm years would be almost impossible without that effect.
Last year, Michael Mann from Pennsylvania State University
published a paper showing the then-record temperatures in 2014 would have had
less than a one in a million chance of occurring naturally.
“We have a follow-up article that we’ve submitted showing
that the likelihood of three consecutive record-breaking years such as we saw
in 2015-2017 was similarly unlikely,” he told the Guardian over email. “In
short, we can only explain the onslaught of record warm years by accounting for
human-caused warming of the planet.”
Andy Pitman from the University of New South Wales in
Sydney, Australia said the onslaught of very rapid warming in the past few
years is likely a result of the climate system “catching up” after a period of
relative slow warming caused by natural variability – the so-called “hiatus”.
“I do not think the recent anomalies change anything from a
science perspective,” he said. “The Earth is warming at about the long-term
rates that were expected and predicted [by models].”
But Pitman said the ongoing trend was “entirely
inconsistent” with the target of keeping warming at just 1.5C above
pre-industrial temperatures.
Current trends suggest the 1.5C barrier would be breached in
the 2040s, with some studies suggesting it might happen much sooner.
“In my view, to limit warming to 2C requires both deep and
rapid cuts and a climate sensitivity on the lower end of the current range,”
Pitman said. “I see no evidence that the climate sensitivity is on the lower
end of the current range, unfortunately.”
“It would be a good idea to cut greenhouse gas emissions
rather faster than we are.”
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