Yale Environment 360
- Fred Pearce
Net-zero emissions — balancing emissions by absorbing equivalent amounts of
CO2 from the atmosphere — is the defining approach of international climate
efforts. But some scientists are arguing that this strategy simply allows
the perpetuation of the status quo and is certain to fail.
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A coal processing plant in Hejin in central China's Shanxi
Province. Associated Press
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Net zero. Those two words have become the near-universal language for
policymakers intent on sealing a deal at the UN climate conference in Glasgow,
Scotland in November.
But are they the key to fulfilling the
promises to hold warming to 1.5 degrees made at a similar climate summit in
Paris six years ago, or, as some scientists and activists are now saying, are
they a dangerous delusion to which climate scientists have become complicit?
Achieving “net zero” requires that any carbon dioxide or other greenhouse gas
emissions are balanced by absorbing an equivalent amount of CO2 from the
atmosphere — sometimes called negative emissions.
More than 100
countries, including the biggest three emitters — China, the United States, and
the European Union — have pledged to achieve net-zero targets in the coming
decades. They are being applauded for finally getting a grip on climate
change.
But while the net-zero strategy has united policymakers, it has divided climate
scientists and activists. Some see the rush to make net-zero pledges in the
run-up to Glasgow as a huge success for climate action.
But in a
blistering
commentary
last month, a former chair of the Intergovernmental Panel on Climate Change
(IPCC), Robert Watson, and two co-authors denounced net zero as a trap set by
industrialists and governments to hoodwink the world and lambasted climate
researchers for showing “cowardice” in not calling them out.
Net-zero “helps perpetuate a belief in technological salvation and
diminishes the sense of urgency,” the critics write.
The hope is that allowing negative emissions to balance continued CO2 emissions
as part of net-zero policies will provide a safety net for industries where it
is technically impossible to eliminate all emissions — in aviation and
agriculture, for instance.
The negative emissions might be achieved
by increasing CO2 take-up by forests and other ecosystems, or by using
industrial chemistry to capture CO2 from the air. But some fear the safety net
will become a cover for business-as-usual in highly polluting industries.
The debate is as much about the politics of driving down emissions as about
climate science or the potential of technology.
Watson was chair of the IPCC from 1997 until 2002, when the U.S. administration
of President George W. Bush refused to nominate the former NASA climate
scientist for a second term. Since then he has worked as an academic, currently
at the University of East Anglia.
He and his co-authors wrote last
month that while net zero might be “a great idea, in principle,” in practice it
“helps perpetuate a belief in technological salvation and diminishes the sense
of urgency surrounding the need to curb emissions now.”
Scientists
who support the current push for net-zero, they contend, have “licensed a
recklessly cavalier ‘burn now, pay later’ approach, which has seen carbon
emissions continue to soar.”
Watson and his colleagues admit to their own roles. “We admit that it deceived
us,” he and fellow climate scientists James Dyke of Exeter University and
Wolfgang Knorr of Lund University in Sweden wrote. But “the time has come to
voice our fears and be honest with wider society… Current net zero policies will
not keep warming to within 1.5 degrees, because they were never intended to.
They were and still are driven by a need to protect business as usual.”
Watson’s stand — especially coming from a former IPCC boss — has angered some
fellow researchers. In a
riposte
published this month, Richard Black at Imperial College London said it makes
little sense to attack net zero when it is “the defining lens through which many
governments, businesses, NGOs and other types of entity view decarbonization.”
Black told
Yale Environment 360, “high-carbon advocates
have always found excuses to delay, and would do so whatever the policy
framing.” But “it has nothing to do with net zero
per se.”
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Steam turbines at a carbon-capture-and-storage pilot project at
the Mountaineer coal-burning power plant in West Virginia in 2009.
The project was discontinued in 2011. SAUL LOEB/AFP via Getty Images
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In any case, Black is upbeat. In March, he was lead author of an
analysis
of net-zero commitments that argued that “the global momentum on net zero
represents an exciting window.” Besides 124 national governments committing to
adopting various versions of net zero as targets, he found net-zero pledges from
more than 1,500 major companies, representing $14 trillion in revenues.
Black agrees that not all these governments and businesses intend to honor their
pledges. And auditing whether they do so is particularly difficult where those
pledges involve offsetting their continued emissions by buying paper
certificates from other organizations that claim to have prevented emissions
elsewhere or absorbed CO2 in forests.
“There are big flaws in how net zero is being implemented in some cases,” Black
said. “But pledging a target means that the entity can be held to account by
voters, shareholders, or customers.”
This is happening, Black says. He cites the example of the German government.
Last month the country’s
highest court ordered
it to up its short-term emissions reductions to ensure that its mid-century
net-zero target did not leave a disproportionate share of the responsibility to
future generations.
Industries too will be judged. The fossil-fuel industry’s public commitments to
net zero by 2050 will from now on be compared with a
detailed road map
for achieving net zero across the energy industry published this month by the
International Energy Agency (IEA), an intergovernmental body long considered by
environmentalists as an apologist for fossil fuel companies.
If properly designed, nature-based solutions “can have a powerful role in
reducing temperatures,” a new analysis says.
No longer. The IEA
now says
that meeting net zero requires an immediate worldwide end to approvals of new
oil and gas fields — meaning all drilling for more oil or gas reserves should
cease. This puts it at odds with oil giants that are promoting corporate
net-zero strategies while continuing to search for more oil.
These include Shell. Its shareholders this month endorsed a strategy for making
its business net zero by 2050. But a minority protested that the strategy
contravenes the IEA’s call to end all fossil-fuel expansion now. Instead, the
Shell plan anticipates a 20-percent increase in gas production by 2030.
Shell’s version of achieving net zero relies heavily on investment in forest
projects to offset its emissions. Several have already proved controversial.
Following an
analysis
of the company’s net-zero strategy that they coauthored, Johan Rockstrom of the
Stockholm Resilience Center and Gail Whiteman of the University of Execter said
the negative emissions that Shell will need to offset its continued fossil-fuel
activity “requires a forest the size of Brazil.”
Rockstrom and Whiteman call for the company to be drummed out of net-zero
initiatives, such as the UN’s
Race to Zero campaign, and
questions its role advising the British government in the run-up to the Glasgow
climate conference.
IEA director
Fatih Birol
also says net zero requires a global program for early shutdown of coal-fired
power stations, especially in Asia. Yet signatories to net-zero policies,
including the government of China, continue to fund new coal-plants, as do major
finance houses such as Barclays and BNP Paribas, despite both joining a UN
Net-Zero Banking Alliance.
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A coal-fired power plant in Yokohama, Japan. Associated Press
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Some environmental NGOs, such as The Nature Conservancy, nonetheless back net
zero and have created their own offsetting projects to help companies take
advantage of emission offsets. But others decry it. Friends of the Earth calls
it “chasing climate unicorns,” allowing polluters to “hide behind the ‘net’ in
net zero, claiming that they just need to pay someone else to remove carbon.”
Dyke told
e360: “Net zero policies are best understood as the latest
manifestation of a dysfunctional climate policy system” — the latest “framing”
by apologists for the status quo.
He believes the slippery slope began in the 1990s when there was a push to
persuade a reluctant U.S. to address climate change by allowing it to count the
carbon absorbed by its forests as a contribution. The idea, says Dyke, was that
“if it managed its forests well,” then the carbon stored “should be subtracted
from its obligations to limit the burning of coal, oil, and gas.“
Technological fixes followed. At the climate conference in Copenhagen in 2009,
companies promised to develop carbon capture and storage (CCS), the capture of
CO2 as it went up power-station stacks for burial underground. But a decade on,
he says, there are no such facilities in practical large-scale operation.
By Paris in 2015, the “new savior technology” was Bioenergy with Carbon Capture
and Storage (BECCS). This combined CCS with burning wood or other bioenergy
crops in power stations. If the wood or other fuel was then regrown, it would
absorb more carbon from the air. In this way, the world could combine generating
energy and negative emissions.
As part of C02 reduction strategies, some countries are claiming
natural processes already included in future climate models.
But since Paris, it has emerged that full deployment of BECCS would require
frequently harvested tree plantations or bioenergy crops covering anywhere from
25 to 80 percent of all land currently under cultivation. That would “devastate
biodiversity,” according to Watson, who since his stint at the IPCC has also
chaired the Intergovernmental Science-Policy Platform on Biodiversity and
Ecosystem Services.
“The end result of all these diversions,” Dyke said, “has been the same — no
effective mitigation.” Emissions today are 60 percent above the level of 1992,
the year the world first agreed at the Rio Earth Summit to prevent “dangerous”
climate change. ”Net zero is just the latest example of wishful thinking that
effectively stops us critically reflecting on why we have failed,” he said.
In the search for means of achieving negative emissions to meet net-zero
targets, there has been an increasing focus on what are called “nature-based
solutions.” These involve using forest planting or restoration of carbon-holding
wetlands, such as peat bogs or mangrove swamps, to draw CO2 from the air.
The term was coined in 2017 by Bronson Griscom, then at The Nature Conservancy.
In a
new analysis
by him and others in the journal
Nature this month, Griscom says they
“can have a powerful role in reducing temperatures,” including in the long term,
if they are properly designed and have good accounting standards.
But this too has drawn the ire of Watson and his co-authors. Knorr told
e360 that while it was true that restored ecosystems can hold more
carbon, calculating any additional benefit from short-term interventions is all
but impossible. It is also wide open to misrepresentation, he said, as companies
and countries adopt natural carbon sinks as part of their plans for net zero.
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Mangroves on the Osa Peninsula of Costa Rica. Mangrove forests
are major carbon sinks. Prisma by Dukas Presseagentur GmbH/ Alamy Stock Photo
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“About a third of current CO2 emissions are taken up by forests and other
ecosystems,” Knorr said. “Double counting is essentially unavoidable. We need
the natural sink
plus mitigation, not the sink
as mitigation.”
Potentially even worse, he warns, climate change itself “could weaken forests
and make them prone to fires or insect attacks,” at which point they start
releasing their carbon. For such reasons “nature-based solutions don’t offer a
guarantee that carbon will remain stored away. It’s a Pandora’s box,” Knorr
said.
Climate modeler Myles Allen at Oxford University, a co-author of this month’s
Nature paper on nature-based solutions, agrees. Climate-based solutions
are “temporary and at risk of reversal as the world warms,” he told
e360.
Most climate models show the biosphere
switching from as sink to a source of carbon over the course of this century.
“So storing fossil carbon there is risky,” Allen said, “unless you have a plan
to re-store it somewhere permanently if it starts to leak out again — which no
offsetting schemes even think about.”
Such concerns have not stopped some countries from including their natural sinks
in calculating their contributions to climate change. Bhutan and Suriname both
claim to be carbon negative because their trees currently absorb more than their
industries emit.
But this makes no scientific sense, says critics,
because they are claiming as part of their CO2 reduction strategies natural
processes that are already included in models of future climate. The danger is
that other countries may try to join them.
When China recently
committed to achieving net zero by 2060, it said that it would achieve this in
part through nature-based solutions. The government’s special envoy of climate,
Xie Zhenhua, said in 2019 that nature-based solutions could cut China’s net
emissions by a third.
Last year, in a
Nature paper, Yi Liu
of the Chinese Academy of Sciences and colleagues
calculated
that between 2010 and 2016 China’s forests soaked up the equivalent of 45
percent of its human-made CO2 emissions.
Similarly, the U.S. Forest Service says 11 percent of national CO2 emissions are
“offset” by American forests.
If the world’s two biggest emitters
start claiming that the carbon being absorbed in these existing forests could be
offset against their emissions to achieve net zero, then the scientific basis
for net-zero policies to end climate change would swiftly unravel.
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