Washington Post - Chris Mooney
The Paris Agreement is expected to come into force within the next few months. The Post's Chris Mooney explains where we go from here. (Daron Taylor/The Washington Post)
The entire globe is moving fast to stop climate change. The Paris
climate agreement enters into legal force on Friday, and then shortly
afterwards comes a first global meeting to start implementing it in
Marrakech, Morocco. (Yes, there’s also a U.S. election in there
somewhere that could, er, complicate things.)
But this flurry of activity nonetheless faces a grim mathematical reality, a new report from
the United Nations Environment Programme finds. In essence, while the
Paris agreement sets extremely ambitious temperature goals — holding the
world’s warming to “well below” 2 degrees Celsius above pre-industrial
levels, and striving for a 1.5 degree limit — current policies and
promises alone have little chance of attaining them.
Moreover,
because of the unforgiving nature of carbon math — once you emit a ton
of carbon dioxide, you can’t get it back, and it accumulates steadily in
the atmosphere — there is exceedingly little time to change course and
increase ambitions.
“It’s just too little, and it’s not happening
quickly enough,” said Jacqueline McGlade, UNEP’s chief scientist. “If
we don’t see emissions peaking by 2020, then the chances of getting to
1.5 degrees is vanishingly small.”
Such is the upshot of UNEP’s latest installment of its “emissions gap” report, perhaps the definitive study of how much the world is currently emitting, and how much it can emit to remain on course to meet its goals. The difference between the two comprises the gap.
Here are the details (warning, this stuff gets complicated quickly).
Right
now, due to causes ranging from deforestation to transportation, the
world is emitting about 52.7 billion tons, or gigatons, of carbon
dioxide equivalents per year as of 2014. That’s mostly just plain carbon
dioxide, but it also includes emissions of methane, nitrous oxide, and
other greenhouse gases that are converted into units comparable to
carbon dioxide. If you leave those out, the pure carbon dioxide
emissions are about 36 billion tons per year.
However, to hold
global warming below 2 degrees (at least with good odds), the world can
emit no more than 1,000 gigatons of carbon dioxide from the year 2011
onwards — the famous carbon budget. And given that it’s 2016 already,
that number has already shrunken a good bit, by about 150 gigatons. And
of course, the carbon budget is even narrower to hold warming to 1.5
degrees Celsius.
This
is the logic behind the inescapable emissions “gap”: If we want to hold
global warming to 1.5 C, we need to be emitting only 38.8 gigatons of
carbon dioxide equivalents by the year 2030. For 2 degrees C, there’s
only slightly more leeway — 41.8 gigatons.
The promises countries
have made under the Paris agreement don’t remotely get there — at best,
they’d have us at about 53.4 billion tons in 2030. The emissions gap is
therefore between 12 and 14 gigatons per year if you want to keep the
planet at 2 degrees, and between 15 and 17 gigatons per year for 1.5
degrees, says UNEP.
“When you think that one gigaton is the
equivalent of taking all European vehicles off the road for one year,
and the gap is between 12 and 14 gigatons, you see what the scale of the
problem is,” explains McGlade.
Thus, we’re way off course with
very little time to turn things around. The world’s current promises,
says UNEP, would allow the planet to warm by about 3 degrees C above
pre-industrial levels.
And by the way: even these numbers
for keeping warming below 1.5 or 2 degrees tend to assume something
that many scientists think is dubious. They tend to rely on the
assumption that we’ll bust through our carbon budgets but somehow get a
second chance later in the century, once we create technologies that can
somehow withdraw carbon dioxide out of the air again. These scenarios
often have the world removing net amounts carbon dioxide from the
atmosphere after 2050, rather than putting more there. It’s far from
clear that will actually happen, at least at the scale that would be
required.
Granted,
McGlade underscores that this doesn’t mean there is no hope — it just
means that the world has to do massively more, and it has to do it
quickly. Every year, we bank more carbon emissions in the atmosphere.
Every year we fail to bend the curve sharply downwards, it becomes that
much harder to get on the right course.
This is why, McGlade
asserts, emissions have to peak and start to decline by 2020 — just four
short years from now — or else the 1.5 degree target could be gone.
The
Marrakech meeting beginning next week won’t be the place to raise
global ambitions under the Paris process — at the earliest, it appears
that may happen in 2018. But McGlade says in the meantime, there are
other actions that can shrink the emissions gap, including moves by
sub-national players like major corporations, cities, and large scale
land users in the agricultural and forestry sectors. Precious gigatons
can be won back in this way, potentially narrowing the gap.
“Cities don’t have to wait, companies don’t have to wait, society doesn’t have to wait,” says McGlade.
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