The United States can reduce
its carbon footprint to zero by 2050 — but only if the country invests swiftly and
deeply in emerging technologies that draw carbon dioxide out of the atmosphere.
Federal funding of a range
of carbon removal technologies, amounting to as much as $6 billion per year
over the next 10 years, could put the U.S. on a path toward carbon neutrality by mid-century, according to a report released
January 31 by the World Resources Institute, based in Washington, D.C. Being
carbon-neutral means that the amount of U.S. emissions of carbon — primarily from burning fossil fuels like coal, oil
and gas— is
fully offset by the amount of carbon removed from the atmosphere.
Navigating a realistic path
to carbon neutrality is tricky, though, with many scientific, economic and
political uncertainties surrounding the available technologies. But by
combining many different strategies for carbon removal, the report envisions
that the United States could ramp up to removing up to 2 metric gigatons of CO2
a year from the atmosphere by 2050.
This roadmap to carbon
neutrality would devote about two-thirds of that initial decade of funding, or $4
billion a year, to support tree restoration projects across the United States.
Strategies to integrate trees into croplands and pasturelands, for example, are
already well understood. By starting with the trees, the report suggests, the nation could ultimately
remove as much as 7 gigatons of CO2 by 2050 — more than any other carbon removal pathway.
Other carbon removal
technologies have the potential to remove even more CO2 than tree
planting, but would require significant federal investment to become
commercially viable, the report notes. Depending on how mature the technology
is, some of the proposed funding would go to, for example, tax credits to
support emerging technologies such as direct air capture, in
which CO2 is pulled directly from the ambient air using giant fans (SN: 12/17/18). This technology has been
tested in pilot projects but has not yet made the leap to commercial-scale
Other funding would support
more scientifically uncertain but potentially game-changing strategies, such as
carbon mineralization. This CO2-storage concept involves
“mineralizing” the gas, converting it into carbonate minerals, and then sequestering it underground (SN: 8/22/18).
It’s a strategy that is still in the laboratory phase, as scientists wrangle with
its technological challenges.
The new “CarbonShot” report
weighs the costs and benefits of these various approaches toward zero emissions,
says James Mulligan, a senior associate with WRI’s food, forests and water
program. The report “really focuses on [finding] the small set of U.S. federal
policy options” that will kick-start a carbon removal technological boom, says
Mulligan, who previously worked in the U.S. Office of Management and Budget
from April 2014 to July 2017.
asked Mulligan about some of the details of his team’s report, and why the authors
felt this approach was needed for the United States. His responses are edited
for brevity and clarity.
SN: Why is removing 2 gigatons of CO2
a year the target?
such as the 2016 Deep Decarbonization Strategy have consistently shown that, even if we successfully
implement strategies to reduce emissions, there will be a fair amount of
emissions left hanging around by 2050. We’d still need to remove them [to
become carbon-neutral]. Of course it’s conceivable that the U.S. will need to
remove more, if we don’t significantly reduce emissions.
SN: Why does the report discuss carbon
removal technologies that aren’t yet ready for use?
conceivable that we can get 2 gigatons of CO2 out of the atmosphere
with tree planting and direct air capture alone, but that’s a fairly narrow
path to success. We’re approaching carbon removal from a risk management
framework, how to put more options on the table. If carbon mineralization does
come online, it’s ultimately more cost-effective and removes more CO2
from the atmosphere [than tree planting]. I want to have a whole quiver of
options that we can slot in.
SN: The roadmap calls for spending $4
billion a year in the next decade on tree restoration. Why so much?
It’s not just traditional reforestation. We have done extensive scouring of the
landscape for opportunities to get more trees, especially restocking eastern
timberlands and integrating trees into pasturelands. All told, there’s a lot of
uncertainty, but we’re looking at 60 billion trees. Trees cost money,
especially when they’re not going to be harvested. The cost of restoration is
going to exceed benefits to private landowners, but there’s an enormous public
SN: Americans overall support investing in
trees, but less so carbon removal technology. Why?
don’t yet understand the technology; it’s not real yet. They’re just going to
put it out of mind until someone develops it. But I think that policy makers do
understand the opportunity here, and we’re getting real traction. It’ll
permeate the public consciousness as we start to get more pilot projects, real
facilities that people can see and understand.
SN: Why focus so much on federal dollars? What
about state and more local investment?
states are going to play a huge role here, especially in the land sector. State
leadership is critical. But we’re mindful that states have to balance their
budgets, that they’re in a very budget-constrained environment. Given the
investment scale needed for deployment, it’s going to have to come from direct
federal investment if we’re going to get the private sector involved. Still, on
the technological side, there are things states can do to create a favorable
environment for investment, such as setting research priorities for state
SN: How likely is it that this roadmap will
get support from politicians and government?
think it’s quite feasible. The biggest chunk is the $4 billion a year for
trees, which is equivalent to what we spend on photovoltaics [solar panels] or
in fossil fuel subsidies. The carbon removal dimension could very well be a
co-benefit there, in addition to things like air quality and water quality
benefits. And we’re already getting interest from [politicians].
On the technological side,
there’s similar interest, and from both parties, which is really important.
SN: What else should people take away from
It’s important for people to remember that we need to do this in addition to
reducing emissions. Also, given what’s at stake [with climate change], it’s
important that we take this risk management approach, putting as many options
on the table as we can.