By Chris Mooney
Global
carbon dioxide emissions are projected to rise again in 2017, climate
scientists reported Monday, a troubling development for the environment
and a major disappointment for those who had hoped emissions of the
climate change-causing gas had at last peaked.
The
emissions from fossil fuel burning and industrial uses are projected to
rise by up to 2 percent in 2017, as well as to rise again in 2018, the
scientists told a group of international officials gathered for a United
Nations climate conference in Bonn, Germany.
Despite
global economic growth, total emissions held level from 2014 to 2016 at
about 36 billion tons per year, stoking hope among many climate change
advocates that emissions had reached an all-time high point and would
subsequently begin to decline. But that was not to be, the new analysis
suggests.
“The
temporary hiatus appears to have ended in 2017,” wrote Stanford
University’s Rob Jackson, who along with colleagues at the Global Carbon
Project tracked 2017 emissions to date and projected them forward.
“Economic projections suggest further emissions growth in 2018 is
likely.”
The
renewed rise is a troubling development for the global effort to keep
atmospheric concentrations of greenhouse gases below the levels needed
to mitigate the worst effects of climate change. The more we emit now,
scientists say, the more severe cuts will have to be later. That’s
because of the very long atmospheric lifetime of carbon dioxide, which
means we can only emit a fixed amount in total if we want to stay within
key climate goals.
“It’s
sort of, lose one year now, you have to pick up five years later,” said
Glen Peters, one of the study’s co-authors and a researcher at the
Center for International Climate Research in Oslo.
Emissions
are forecast to reach around 37 billion tons of carbon dioxide from
fossil fuel burning and industrial activity in 2017, said the group,
which published the results in the journal Environmental Research
Letters and more detailed findings in Earth System Science Data
Discussions. The renewed increase is driven largely by more fossil fuel
burning in China and many other nations.
“We’ve
been lucky in the last three years with emissions being flat without
any real policy driving it,” Peters said. “If we want to ensure that
emissions remain flat we have to put policies in place . . . and the
second step is to start to drive emissions down.”
Peters
said the 2017 number would be a record high for emissions from fossil
fuel burning and industrial uses (such as cement), although carbon
emissions from deforestation and land-use changes were actually higher
in 2015.
The
scientists also acknowledge some uncertainty in their estimate, meaning
that the 2017 emissions rise could be as low as 1 percent or as high as
3 percent.
All
in all, the finding is bad news for global climate policy. The Paris
agreement, now supported by every nation except for the United States,
aims to limit the warming of the planet to “well below” 2 degrees
Celsius (3.6 degrees Fahrenheit) above preindustrial levels, and to try
to hold warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit).
But this requires emissions not just to stay flat but to go down — rapidly.
“The
2017 emissions data make it crystal clear that urgent and very serious
emissions reductions are needed to stop global warming below 2° C, as
was unanimously agreed in Paris,” Stefan Rahmstorf, a climate scientist
at the Potsdam Institute for Climate Impact Research in Germany, said in
an email. Rahmstorf was not involved with the current work.
Rahmstorf
said there are currently about 600 billion remaining tons of carbon
dioxide that can be emitted if the world is to have a good chance of
keeping warming considerably below 2 degrees Celsius, and with some 40
billion tons of emissions each year, that leaves just 15 years.
“If
we start to ramp down emissions from now on we can stretch this budget
to last us about 30 years,” he said. “With every year that we wait we
will have to stop using fossil energy even earlier.”
The rise of global emissions projected for the year 2017 in the current research is attributable to multiple causes.
In
particular, China’s emissions were projected to increase by 3.5 percent
in 2017 as the country consumed more of all three of the top fossil
fuels — coal, natural gas and oil. China is the single largest emitting
country.
India,
which has been experiencing rapid emissions growth, will pull back to 2
percent growth in 2017 because of economic contraction, the research
suggests. Emissions from the United States and European Union are
projected to decline 0.4 percent and 0.2 percent, respectively. But
emissions for the rest of the globe – which, in total, are even larger
than China’s – will rise by close to 2 percent, according to the
projection.
If
the increase continues, what many hoped was a plateau in emissions seen
from 2014 to 2016 could come to look more like a pause.
During
that era, many cited a broad “decoupling” of economic growth and
emissions growth, thanks in part to greater energy efficiency and
renewable energy. And there’s no denying that renewables are continuing
to grow around the world – making it hard to know quite what to make of
the current emissions rise.
“It’s too early to say whether it’s a long-term trend, or just a one-off little blip,” Peters said.
The
new results reinforce just how much of the globe’s emissions trajectory
depends on China, its largest emitter. China took a number of steps to
cut back coal emissions in the past three years, notes Joanna Lewis, a
Georgetown University professor who studies energy trends in the
country. This led to less coal use in the electricity and industrial
sectors.
“What
is less clear is whether these trends can continue,” Lewis said by
email. “Reduced plant operation and closures around the country are
putting huge pressures on local governments to deal with slowing
economic growth and unemployment. Overcapacity in these sectors, and
particularly an overbuild of coal plants, means there is pressure to
increase coal electricity production, which is often done through the
curtailment of renewables. As a result, China’s long term CO2 emissions
trends are unclear at best.”
While
37 billion tons of carbon dioxide from fossil fuels and industry
represent the lion’s share of the globe’s emissions, there are also
several billion tons of carbon dioxide each year from deforestation and
other changes in how humans use land. When it comes to global tree loss,
there are also worrying signs that it is not abating as hoped.
There
are also rising emissions of methane, a greenhouse gas that is a
stronger and faster warming agent, although not nearly as long-lived in
the atmosphere as carbon dioxide. There is still a debate over where the
methane growth is coming from, but much of it could be from animal
agriculture.
The
new findings will be immediately relevant to the proceedings in Bonn,
since one part of the agenda involves laying the groundwork for a
“facilitative dialogue” to take place next year, in which countries will
take a hard look at where their emissions are, and where they need to
be, to live up to the Paris goals.
Higher
emissions will, in this context, inevitably mean deeper cuts will be
required of participating nations — even as deadlines for avoiding the
most severe effects of global warming draw near.
