Critics question assumptions at core of California's Low Carbon Fuel Standard
This is Part 2 of a three-part series examining the controversies and conflicts surrounding the future of the California Air Resources Board’s Low Carbon Fuel Standard. Read Part 1. Michael Wara is worried that a key California climate regulator is about to lock the state into the mistakes of the past. And it’s largely because the agency — the California Air Resources Board — is putting too much faith in its ability to predict the future. Wara, director of Stanford University’s Climate and Energy Policy Program, led a team of climate scientists that in September presented CARB with a proposal to set its beleaguered Low Carbon Fuel Standard program on the right path for the planet. The proposal, developed on behalf of CARB’s Environmental Justice Advisory Committee, aims to curb what have become lavish subsidies for renewable diesel and dairy biogas, combustion fuels that are not up to the task of cleaning up transportation, the state’s largest source of greenhouse gas emissions. The agency has issued decisions in recent years that have made California a global leader in electric vehicle adoption. But it has also allowed the Low Carbon Fuel Standard — a marquee program that raises some $4 billion each year to cut carbon emissions from transportation — to rely heavily on crop- and cow-manure-based biofuels that Wara and other climate scientists say are not only an ineffective way to spend the money but also actively harmful for the planet. Now, as the agency prepares to vote on a plan that rejects the environmental-justice proposal in favor of continuing its support of these biofuels, Wara is concerned that CARB is about to lock in its disastrous policy for another two decades. “Things are changing really fast in the transportation sector, and CARB deserves credit for that,” Wara said, referring to its EV policies. But that rapid pace of change means that “the future is highly uncertain in the transportation sector,” he said. “The compromises we’re making to get cleaner fuels today may look good today” to CARB analysts, “but not look good in 10 years — and I have no idea how they’ll look in 20 years.” Despite this uncertainty, the staff’s core justification for its preferred biofuel-friendly approach is a model it has created to forecast the optimal pathway for decarbonizing the state’s cars, vans, buses, trucks, trains, planes and even off-road vehicles by 2045. And at the core of that long-range, intricate model is, of course, a set of assumptions. These assumptions are hugely consequential, hotly contested — and shrouded in secrecy. The agency has entered into “very speculative territory” with this model, Wara said, and it may be relying on assumptions that falsely paint electrified transit options as less appealing than biofuels. Groups including Earthjustice, the Union of Concerned Scientists, Food and Water Watch and Wara’s team have challenged these assumptions, warning that they may not only turn out to be wrong but also create an analytical framework that makes better choices look worse by comparison. And though they have their suspicions that CARB’s model gets some things wrong given its strong prioritization of biofuels, they can’t even say that for sure. That’s because CARB hasn’t yet let them see and evaluate the inputs to its model. Wara said he’s “reluctant to say that the modeling is good or bad, or that the alternatives have been fairly considered or not.” Until the data is available to test those assertions, “I honestly have no idea.” But as it stands, it’s far from clear that CARB is ready to reform its approach to modeling the impacts of its Low Carbon Fuel Standard policy quickly enough to address the threat that runaway biofuel subsidies pose to transportation-decarbonization goals. That’s why many of CARB’s critics, including Wara and a group of climate scientists, are pushing the CARB board to not only provide transparency into their modeling efforts but also embrace the environmental-justice proposal the staff has spurned — starting with a limit on the amount of crop-derived renewable diesel flooding the program. Why CARB’s long-range modeling may be discounting the electric future Environmental-justice groups have long argued that CARB is giving renewable diesel and methane captured from cow manure more carbon-cutting and air-pollution-reducing credit than the latest science shows they should receive. Opponents of those fuels have accused the agency of bowing to pressure from powerful oil and agricultural industry interests that are profiting from the existing policies. But one reason CARB puts so much weight on those liquid-fuel-based pathways may be because its analytical and modeling framework simply cannot imagine a low-carbon transportation future without them — at least not with its current assumptions. CARB staff’s December report stated that it rejected the environmental-justice proposal, which was backed by modeling done by Wara’s team, because it would lead to “higher volumes of fossil diesel being used than any of the other scenarios evaluated” and thus higher carbon emissions and air pollution. “Even with a 2035 phaseout of new light-duty vehicle sales and aggressive deadlines for a heavy-duty [vehicle] phaseout, millions of fossil-fueled vehicles will remain on California’s roads for several decades,” CARB spokesperson Dave Clegern told Canary Media in a March email. “They will require cleaner fuels as we move toward 2045 carbon neutrality.” But that finding relies on assumptions about the amount of liquid fuels that will be needed through 2045, Wara noted. In extremely simplified terms, CARB’s modeling methodology “takes as a given how much liquid fuel is required, and then it says, ‘How are we going to get the liquid fuel we need?’” And if biofuels aren’t available to feed that model, it will presume that fossil fuels are being burned to make up the difference. On the other side of that coin, CARB’s model also “takes as a given the amount of electric transport” that will be available 10 and 20 years from now, he said. But given how quickly electric vehicles and batteries to power them are advancing, it’s far from clear that today’s assumptions on that front will hold true — and “if you get that wrong, you get every prediction wrong for the model.” California has set a goal of ending sales of new gasoline-fueled passenger vehicles by 2035, but how quickly EVs are actually adopted will depend on factors that now remain in flux, ranging from automaker investments and charging availability to consumer sentiment. There’s even greater uncertainty about how many medium- and heavy-duty vehicles will be able to convert to electric over the next 20 years, as opposed to needing low-carbon liquid fuel alternatives to diesel, Wara said. Previously held beliefs about the cost and range limits of battery-electric heavy-duty trucks are being shattered on an annual basis. These underlying technological and economic developments are happening so fast that models developed just last summer “cannot simulate what’s happening now and next year,” he said. Why has CARB withheld important data? That brings up another problem, Wara said: No one knows exactly what CARB’s modeling inputs are. They only know the outcomes. “The rulemaking is not transparent because CARB has been unwilling to release files that we need to evaluate it,” he said. For its analysis, Wara’s team used the same optimization modeling platform — the California Transportation Supply, or CATS, model — that CARB developed and uses for its own analysis. But CARB staff has refused to share the underlying data input and output files that informed its latest plan, Wara said.
This is Part 2 of a three-part series examining the controversies and conflicts surrounding the future of the California Air Resources Board's Low Carbon Fuel Standard. Read Part 1 . Michael Wara is worried that a key California climate regulator is about to lock the state into the mistakes of the past. And it’s…
This is Part 2 of a three-part series examining the controversies and conflicts surrounding the future of the California Air Resources Board’s Low Carbon Fuel Standard. Read Part 1.
Michael Wara is worried that a key California climate regulator is about to lock the state into the mistakes of the past. And it’s largely because the agency — the California Air Resources Board — is putting too much faith in its ability to predict the future.
Wara, director of Stanford University’s Climate and Energy Policy Program, led a team of climate scientists that in September presented CARB with a proposal to set its beleaguered Low Carbon Fuel Standard program on the right path for the planet. The proposal, developed on behalf of CARB’s Environmental Justice Advisory Committee, aims to curb what have become lavish subsidies for renewable diesel and dairy biogas, combustion fuels that are not up to the task of cleaning up transportation, the state’s largest source of greenhouse gas emissions.
The agency has issued decisions in recent years that have made California a global leader in electric vehicle adoption. But it has also allowed the Low Carbon Fuel Standard — a marquee program that raises some $4 billion each year to cut carbon emissions from transportation — to rely heavily on crop- and cow-manure-based biofuels that Wara and other climate scientists say are not only an ineffective way to spend the money but also actively harmful for the planet.
Now, as the agency prepares to vote on a plan that rejects the environmental-justice proposal in favor of continuing its support of these biofuels, Wara is concerned that CARB is about to lock in its disastrous policy for another two decades.
“Things are changing really fast in the transportation sector, and CARB deserves credit for that,” Wara said, referring to its EV policies. But that rapid pace of change means that “the future is highly uncertain in the transportation sector,” he said. “The compromises we’re making to get cleaner fuels today may look good today” to CARB analysts, “but not look good in 10 years — and I have no idea how they’ll look in 20 years.”
Despite this uncertainty, the staff’s core justification for its preferred biofuel-friendly approach is a model it has created to forecast the optimal pathway for decarbonizing the state’s cars, vans, buses, trucks, trains, planes and even off-road vehicles by 2045. And at the core of that long-range, intricate model is, of course, a set of assumptions. These assumptions are hugely consequential, hotly contested — and shrouded in secrecy.
The agency has entered into “very speculative territory” with this model, Wara said, and it may be relying on assumptions that falsely paint electrified transit options as less appealing than biofuels.
Groups including Earthjustice, the Union of Concerned Scientists, Food and Water Watch and Wara’s team have challenged these assumptions, warning that they may not only turn out to be wrong but also create an analytical framework that makes better choices look worse by comparison.
And though they have their suspicions that CARB’s model gets some things wrong given its strong prioritization of biofuels, they can’t even say that for sure. That’s because CARB hasn’t yet let them see and evaluate the inputs to its model.
Wara said he’s “reluctant to say that the modeling is good or bad, or that the alternatives have been fairly considered or not.” Until the data is available to test those assertions, “I honestly have no idea.”
But as it stands, it’s far from clear that CARB is ready to reform its approach to modeling the impacts of its Low Carbon Fuel Standard policy quickly enough to address the threat that runaway biofuel subsidies pose to transportation-decarbonization goals. That’s why many of CARB’s critics, including Wara and a group of climate scientists, are pushing the CARB board to not only provide transparency into their modeling efforts but also embrace the environmental-justice proposal the staff has spurned — starting with a limit on the amount of crop-derived renewable diesel flooding the program.
Why CARB’s long-range modeling may be discounting the electric future
Environmental-justice groups have long argued that CARB is giving renewable diesel and methane captured from cow manure more carbon-cutting and air-pollution-reducing credit than the latest science shows they should receive. Opponents of those fuels have accused the agency of bowing to pressure from powerful oil and agricultural industry interests that are profiting from the existing policies.
But one reason CARB puts so much weight on those liquid-fuel-based pathways may be because its analytical and modeling framework simply cannot imagine a low-carbon transportation future without them — at least not with its current assumptions.
CARB staff’s December report stated that it rejected the environmental-justice proposal, which was backed by modeling done by Wara’s team, because it would lead to “higher volumes of fossil diesel being used than any of the other scenarios evaluated” and thus higher carbon emissions and air pollution.
“Even with a 2035 phaseout of new light-duty vehicle sales and aggressive deadlines for a heavy-duty [vehicle] phaseout, millions of fossil-fueled vehicles will remain on California’s roads for several decades,” CARB spokesperson Dave Clegern told Canary Media in a March email. “They will require cleaner fuels as we move toward 2045 carbon neutrality.”
But that finding relies on assumptions about the amount of liquid fuels that will be needed through 2045, Wara noted. In extremely simplified terms, CARB’s modeling methodology “takes as a given how much liquid fuel is required, and then it says, ‘How are we going to get the liquid fuel we need?’”
And if biofuels aren’t available to feed that model, it will presume that fossil fuels are being burned to make up the difference.
On the other side of that coin, CARB’s model also “takes as a given the amount of electric transport” that will be available 10 and 20 years from now, he said. But given how quickly electric vehicles and batteries to power them are advancing, it’s far from clear that today’s assumptions on that front will hold true — and “if you get that wrong, you get every prediction wrong for the model.”
California has set a goal of ending sales of new gasoline-fueled passenger vehicles by 2035, but how quickly EVs are actually adopted will depend on factors that now remain in flux, ranging from automaker investments and charging availability to consumer sentiment.
There’s even greater uncertainty about how many medium- and heavy-duty vehicles will be able to convert to electric over the next 20 years, as opposed to needing low-carbon liquid fuel alternatives to diesel, Wara said. Previously held beliefs about the cost and range limits of battery-electric heavy-duty trucks are being shattered on an annual basis.
These underlying technological and economic developments are happening so fast that models developed just last summer “cannot simulate what’s happening now and next year,” he said.
Why has CARB withheld important data?
That brings up another problem, Wara said: No one knows exactly what CARB’s modeling inputs are. They only know the outcomes.
“The rulemaking is not transparent because CARB has been unwilling to release files that we need to evaluate it,” he said.
For its analysis, Wara’s team used the same optimization modeling platform — the California Transportation Supply, or CATS, model — that CARB developed and uses for its own analysis. But CARB staff has refused to share the underlying data input and output files that informed its latest plan, Wara said.