The opinion
TO BE PUBLISHED IN THE OFFICIAL REPORTS
OFFICE OF THE ATTORNEY GENERAL
State of California
ROB BONTA
Attorney General
_______________
:
OPINION :
: No. 24-201
of :
: July 23, 2024
ROB BONTA :
Attorney General :
:
KARIM J. KENTFIELD :
Deputy Attorney General :
The HONORABLE STEVEN BRADFORD, STATE SENATOR, and the
HONORABLE COTTIE PETRIE-NORRIS, STATE ASSEMBLYMEMBER, have
requested an opinion on a question relating to regulation of greenhouse gases.
QUESTION PRESENTED AND CONCLUSION
Does the term “voluntary carbon offset” in Assembly Bill 1305 include renewable
energy credits (RECs) used outside of the State’s regulatory programs?
No, the term “voluntary carbon offset” does not include RECs used outside of the
State’s regulatory programs because RECs do not claim to reduce greenhouse gases in
the atmosphere or prevent greenhouse gas emissions that would otherwise have occurred.
BACKGROUND
As awareness of climate change continues to grow, individuals and businesses are
increasingly interested in reducing the greenhouse gas emissions associated with their
activities. 1 One instrument used to achieve that goal is a “carbon offset.” A “carbon
1
See, e.g., Assemblymember Jesse Gabriel, Fact Sheet, AB 1305—Voluntary Carbon
Offset Transparency (Feb. 27, 2023) (Bill Author Fact Sheet).
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offset is when one entity” who wishes to reduce its emissions footprint without altering
its activities “pays another entity” to implement emissions reductions. 2 An offset seller
might promise to remove existing greenhouse gases from the atmosphere—for example,
by growing a forest or installing machines that remove carbon dioxide from the air. 3 Or a
seller might promise to prevent future emissions that would otherwise have occurred—
for example, by protecting a forest that would otherwise be destroyed. 4
In California, carbon offsets can be used to satisfy certain state regulatory
requirements. Polluters subject to emissions limits under the State’s Cap-and-Trade
program, for instance, can comply with a small portion of their legal obligations by
purchasing qualifying offsets. 5 Outside of the State’s regulatory regime, carbon offsets
may also be purchased by individuals or businesses on a voluntary basis. 6 Individuals
may purchase offsets to advance personal sustainability goals. And businesses may
purchase offsets to “demonstrate their commitment to reducing their carbon footprint” or
to advertise to consumers that their products are “carbon neutral.” 7
Although carbon offsets used for compliance with state emissions programs are
closely regulated, most offsets sold on the voluntary market are not. 8 Last year,
lawmakers expressed concern that the voluntary offset industry had become a “wild
west.” 9 Recent studies suggested that some offsets on the market “did not represent
2
Off. of Sen. Floor Analyses, 3d reading analysis of Ass. Bill No. 1305 (2023-2024 Reg.
Sess.) Sept. 11, 2023, p. 3 (Senate Analysis).
3
Sen. Judic. Comm., analysis of Ass. Bill No. 1305 (2023-2024 Reg. Sess.) July 7, 2023,
p. 5 (Judiciary Committee Analysis).
4
See Judiciary Committee Analysis, at p. 5.
5
The Cap-and-Trade program “establishes a declining limit on major sources of
[greenhouse gas] emissions throughout California.” (Cal. Air Resources Board, Cap-and-
Trade Program, About, https://ww2.arb.ca.gov/our-work/programs/cap-and-trade-
program/about (as of July 22, 2024).) Regulated entities can use carbon offsets “to
satisfy a small percentage of their overall compliance obligation”—currently, up to four
percent. (Cal. Air Resources Board, Compliance Offset Program, About,
https://ww2.arb.ca.gov/our-work/programs/compliance-offset-program/about (as of July
22, 2024).)
6
See Senate Analysis, at p. 4.
7
Senate Analysis, at p. 4.
8
See Senate Analysis, at p. 5; Bill Author Fact Sheet, at p. 1.
9
Off. of Ass. Floor Analyses, Conc. in Sen. Amends. of Ass. Bill No. 1305 (2023-2024
Reg. Sess.) Sept. 12, 2023, p. 2 (Assembly Analysis).
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genuine carbon reductions.” 10 Such “junk offsets” defraud purchasers when the promised
carbon benefits are not delivered. 11 And businesses that rely on invalid offsets in their
carbon accounting may make inaccurate claims to customers and investors—for example,
as to whether their products are carbon neutral. 12
To increase accountability and transparency in the offset market, the Legislature in
2023 enacted Assembly Bill 1305. 13 That statute requires any business that markets or
sells a “voluntary carbon offset” within the State to disclose specified information on its
website about the underlying emissions-reduction project. 14 Sellers must disclose the
project’s location and timeline, the protocol used to estimate emissions benefits, and the
annual quantity of emissions reduced or carbon removed, among other information. 15 A
business that “purchases or uses voluntary carbon offsets” must make analogous
disclosures if it advertises “significant” emissions reductions, “carbon neutral[ity],” or
similar environmental claims. 16 Regulated entities must update disclosures annually or
face civil penalties. 17
The new disclosure rules apply to products that claim to reduce atmospheric
greenhouse gas levels. Specifically, the statute defines a “voluntary carbon offset” as
“any product sold or marketed in the state that claims to be a ‘greenhouse gas emissions
offset,’ a ‘voluntary emissions reduction,’ [or] a ‘retail offset.’” 18 It also includes “any
like term . . . that connotes that the product” either “corresponds to a reduction in the
amount of greenhouse gases present in the atmosphere” or “prevents the emission of
greenhouse gases into the atmosphere that would have otherwise” occurred. 19 Because
the statute is focused on the voluntary consumer market, a product is not a “voluntary
10
Bill Author Fact Sheet, at p. 1; see Senate Analysis, at p. 5.
11
Senate Analysis, at p. 5.
12
Senate Analysis, at p. 5.
13
See Stats. 2023, ch. 365, § 1 (enacting Ass. Bill No. 1305), codified at Health & Safety
Code, Div. 26, Part 10, §§ 44475-44475.3; Assembly Analysis, at p. 2.
14
Health & Safety Code, § 44475.
15
Health & Safety Code, § 44475, subds. (a)-(c).
16
Health & Safety Code, § 44475.1.
17
Health & Safety Code, § 44475.3.
18
Health & Safety Code, § 44475, subd. (d)(3)(A).
19
Health & Safety Code, § 44475, subd. (d)(3)(A).
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carbon offset” if it “correspond[s] to legal or regulatory mandates” for reducing
atmospheric greenhouse gases or preventing emissions. 20
This opinion request asks whether AB 1305’s definition of “voluntary carbon
offset” encompasses a type of regulatory instrument known as a “renewable energy
certificate” or “renewable energy credit” (REC, pronounced like the word “wreck”). A
REC “is a tradeable, market-based instrument that represents the legal property rights to
the ‘renewable-ness’—or all non-power attributes—of renewable electricity
generation.” 21 For each “unit of electricity” that is “generated and delivered by an
eligible renewable energy resource,” such as a solar or wind facility, a REC is created as
a “certificate of proof.” 22 It represents the “renewable and environmental attributes
associated with the [electricity] production.” 23 RECs are traded on regulated markets and
may be sold with or without the associated unit of electricity. 24
RECs are used by energy suppliers and consumers to support claims that
electricity was generated from renewable resources. For example, if a business purchases
renewable electricity along with the associated RECs, then it can claim ownership and
use of clean energy. But if the business instead buys the same electricity without the
associated RECs, then it cannot claim to own or use zero-emissions energy because it
would not own the “renewable and environmental attributes associated with the
[electricity] production.” 25 Instead, the purchaser of the associated RECs would obtain
the “exclusive right[] to characterize” the corresponding quantity of energy as “zero-
emissions electricity.” 26
In California, energy suppliers use RECs to comply with their obligations under
the Renewables Portfolio Standard program (RPS), administered by the California Public
20
Health & Safety Code, § 44475, subd. (d)(3)(B).
21
U.S. Environmental Protection Agency, Renewable Energy Certificate Monetization,
https://www.epa.gov/greenpower/renewable-energy-certificate-monetization (as of July
22, 2024).
22
Pub. Util. Code, § 399.12, subd. (h)(1).
23
Pub. Util. Code, § 399.12, subd. (h)(2).
24
See Pub. Util. Code, § 399.25, subd. (c); Cal. Energy Commission, PSD Frequently
Asked Questions, https://www.energy.ca.gov/programs-and-topics/programs/power-
source-disclosure-program/psd-frequently-asked-questions (as of July 22, 2024).
25
Pub. Util. Code, § 399.12, subd. (h)(2) (REC definition).
26
U.S. Environmental Protection Agency, Offsets and RECs: What’s the Difference?
(Feb. 2018), p. 4, https://www.epa.gov/sites/default/files/2018-
03/documents/ggp_guide_recs_offsets.pdf (as of July 22, 2024) (EPA Offsets and
RECs).
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Utilities Commission and the California Energy Commission. The RPS program requires
that an increasing percentage of electricity sold in the State is generated from renewable
energy resources. 27 The program currently mandates, for instance, that 60 percent of
retail electricity sales must be served by renewable energy by 2030. 28 Each compliance
period, retail electricity suppliers must furnish RECs to regulators to demonstrate that the
required percentage of electricity was derived from renewable resources. 29 Suppliers can
acquire RECs either by directly generating renewable electricity or by buying RECs on
regulated markets.
Relevant here, RECs are also sold for use outside the RPS program on a voluntary
basis to support claims of clean energy generation and use. A business that wishes to
advertise products manufactured using zero-emissions energy, for instance, might support
that claim by buying RECs to match the nonrenewable energy it obtains from the utility
grid. 30 “By purchasing RECs and electricity separately,” organizations can effectively
“obtain green power” in areas where renewable energy is otherwise unavailable. 31
ANALYSIS
The question presented here is whether RECs sold for non-regulatory use outside
of the State’s RPS program are “voluntary carbon offsets” subject to AB 1305’s
disclosure requirements. We conclude that they are not.
As discussed, AB 1305 defines a “voluntary carbon offset” as
any product sold or marketed in the state that claims to be a “greenhouse gas
emissions offset,” a “voluntary emissions reduction,” a “retail offset,” or any like
term, that connotes that the product represents or corresponds to a reduction in the
amount of greenhouse gases present in the atmosphere or that prevents the
27
See Pub. Util. Code, § 399.11 et seq.; Cal. Public Utilities Commission, Renewables
Portfolio Standard (RPS) Program, https://www.cpuc.ca.gov/rps (as of July 22, 2024);
Cal. Energy Commission, Renewables Portfolio Standard—RPS,
https://www.energy.ca.gov/programs-and-topics/programs/renewables-portfolio-standard
(as of July 22, 2024).
28
See Cal. Public Utilities Commission, Renewables Portfolio Standard (RPS) Program,
https://www.cpuc.ca.gov/rps (as of July 22, 2024).
29
See Pub. Util. Code, § 399.21; Cal. Public Utilities Commission, RPS Compliance and
Reporting, https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/electric-
power-procurement/rps/rps-compliance-rules-and-process/rps-compliance-and-reporting
(as of July 22, 2024).
30
See EPA Offsets and RECs, at p. 5.
31
EPA Offsets and RECs, at p. 5.
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emission of greenhouse gases into the atmosphere that would have otherwise been
emitted. 32
In other words, a voluntary carbon offset must “claim”—directly or by implication—to
either reduce greenhouse gases in the atmosphere or prevent future emissions that would
otherwise have occurred.
The seller of a REC, however, makes no such claim. A REC does not directly
promise to reduce greenhouse gases or prevent future emissions. It does not purport to be
a “greenhouse gas emissions offset,” a “voluntary emissions reduction,” a “retail offset,”
or any other product that expressly claims to alter atmospheric greenhouse gas levels. 33
Nor does a REC make such a claim indirectly. 34 First, a REC does not connote
that it “represents or corresponds to a reduction in the amount of greenhouse gases
present in the atmosphere.” 35 A REC instead conveys ownership of the non-power
attributes of one unit of renewable electricity generation. 36 Although renewable
electricity generation does not increase the amount of greenhouse gases in the
atmosphere, the generation of renewable energy does not necessarily reduce existing
atmospheric greenhouse gases either.
Second, a REC does not connote that it “prevents the emission of greenhouse
gases into the atmosphere that would have otherwise” occurred. 37 To be sure, the
generation of renewable electricity will sometimes avoid carbon dioxide emissions by
displacing non-renewable energy sources. “Given the integrated nature of the power
grid, adding electricity to the grid from one generator will result in the instantaneous
reduction in generation from other generators,” assuming no change in energy demand. 38
32
Health & Safety Code, § 44475, subd. (d)(3)(A), italics added. Because a “voluntary
carbon offset” does not include a product that “correspond[s] to legal or regulatory
mandates” for preventing greenhouse gas emissions (id., § 44475, subd. (d)(3)(B)), the
definition expressly excludes a REC used for compliance with the State’s RPS program.
33
Health & Safety Code, § 44475, subd. (d)(3)(A).
34
See Health & Safety Code, § 44475, subd. (d)(3)(A) (a “voluntary carbon offset”
includes a product that “connotes” that it reduces greenhouse gas levels or prevents future
emissions); e.g., American Heritage Dict. (5th ed. 2016) p. 390 [“connote”] (“To suggest
or imply in addition to literal meaning”).
35
Health & Safety Code, § 44475, subd. (d)(3)(A).
36
Pub. Util. Code, § 399.12, subd. (h)(2).
37
Health & Safety Code, § 44475, subd. (d)(3)(A).
38
W. Virginia v. Env’t Prot. Agency (2022) 597 U.S. 697, 713, internal quotation marks
omitted.
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So at times when the grid is being powered in part by fossil fuels, adding renewable
electricity to the grid may trade off with fossil fuel generation—thereby avoiding the
associated greenhouse gas emissions.
In other circumstances, however, adding renewable electricity to the grid will not
displace fossil fuel generation. If the grid is already being powered entirely by renewable
resources—as has regularly occurred in California within the past year—then generating
additional renewable electricity at such a time will not reduce greenhouse gas emissions
but will instead displace other clean energy sources. 39 And at times when energy demand
threatens to exceed available supply—for example, during extreme heat events—adding
renewable electricity to the grid will not displace any other generation source; it will
simply increase the overall electricity supply to satisfy unmet consumer demand. 40
As these examples illustrate, the generation of renewable energy may or may not
reduce fossil fuel generation, depending on the circumstances. And a REC itself makes
no claim about what would have happened if the associated unit of clean electricity had
not been generated—for example, about whether fossil fuel generation would otherwise
have been greater. 41 For these reasons, a REC does not connote that it “prevents the
emission of greenhouse gases . . . that would have otherwise been emitted.” 42 And
because a REC makes no claim to be a “greenhouse gas emissions offset,” a “voluntary
emissions reduction,” a “retail offset,” or any other product that promises to reduce
atmospheric greenhouse gas levels or prevent future emissions, it falls outside the
definition of a “voluntary carbon offset.” 43
Other aspects of AB 1305 reinforce our conclusion. The statute requires the seller
of a voluntary carbon offset to disclose information about the underlying offset project,
39
See Governor Gavin Newsom, California’s Grid Keeps Setting New Clean Energy
Records (Apr. 19, 2024), https://www.gov.ca.gov/2024/04/19/californias-grid-keeps-
setting-new-clean-energy-records (as of July 22, 2024); Fast Company, California just
went 9.25 hours using only renewable energy (Apr. 23, 2024),
https://www.fastcompany.com/91110863/california-renewable-energy-grid (as of July
22, 2024) (“Nearly every day for the last six weeks, California’s electric grid has run on
solar, wind, and other clean energy sources for hours at a time”).
40
See U.S. Environmental Protection Agency, Carbon Pollution Emission Guidelines for
Existing Stationary Sources: Electric Utility Generating Units, 80 Fed.Reg. 64662, 64769
(Oct. 23, 2015) (“[A]dding electricity to the grid from one generator will result in the
instantaneous reduction in generation from other generators” if “demand is held
constant,” italics added).
41
See Pub. Util. Code, § 399.12, subd. (h)(1)-(2) (REC definition).
42
Health & Safety Code, § 44475, subd. (d)(3)(A).
43
See Health & Safety Code, § 44475, subd. (d)(3)(A).
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including the annual quantity of greenhouse gases reduced or avoided. 44 That quantity is
measured by volume of gas, e.g., metric tons of carbon dioxide. 45 But a REC is measured
differently: in units of electricity, megawatt-hours. 46 And a REC cannot be converted
into a quantity of avoided emissions without additional assumptions, inputs, and
calculations. 47 The fact that a REC is not measured in the units used to quantify
reductions in greenhouse gas levels is further evidence that a REC does not make the type
of emissions-reduction “claim” required for a “voluntary carbon offset.” 48
Our understanding of the statutory text aligns with AB 1305’s purpose. As
described above, the Legislature’s concern was that consumers are being “defrauded” by
unregulated products that promise to reduce greenhouse gas levels yet fail to do so. 49
Such promises can be difficult to verify, as the underlying carbon accounting can be
“complicated” and “inscrutable.” 50 The Legislature was particularly concerned about
offsets promising to prevent future emissions, which depend on difficult-to-verify claims
about what would have happened without the offset’s purchase. 51
To increase transparency, AB 1305 requires an offset seller to disclose information
about the underlying offset project—thereby enabling “independent analyses” of the
product’s greenhouse gas-reduction claims. 52 But where a product, like a REC, does not
claim to reduce greenhouse gases, AB 1305’s concerns are not implicated. There is no
risk that a REC purchaser would be misled by complex carbon accounting or uncertain
counter-factual scenarios because a REC makes no such claims. 53 And the only claim
44
Health & Safety Code, § 44475, subd. (a)(10).
45
See, e.g., Cal. Code Regs., tit. 17, § 95980 (measuring offsets in metric tons of carbon
dioxide for Cap-and-Trade program).
46
Pub. Util. Code, § 399.12, subd. (h)(1).
47
See ante, fns. 37-40 (the quantity of greenhouse gas emissions avoided by renewable
electricity generation, if any, depends on various external factors such as consumer
energy demand and alternative power grid suppliers).
48
Health & Safety Code, § 44475, subd. (d)(3)(A).
49
Senate Analysis, at p. 5; see Bill Author Fact Sheet, at p. 1.
50
Senate Analysis, at p. 4.
51
See Senate Analysis, at p. 4 (where an offset promises to protect a forest, for example,
it may be difficult to determine whether the forest would otherwise have been destroyed).
52
Judiciary Committee Analysis, at p. 8; see Bill Author Fact Sheet, at p. 1.
53
See Senate Analysis, at p. 4.
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that a REC does make—to convey the non-power attributes of a unit of clean
electricity—is already carefully regulated by other state laws. 54
Finally, our analysis is consistent with the view of the United States
Environmental Protection Agency. The EPA has explained that offsets and RECs “are
fundamentally different instruments” that are “not interchangeable.” 55 The two
instruments serve different purposes: offsets “represent emissions reductions,” whereas
RECs “convey environmental attributes and renewable electricity use claims.” 56 And
they are measured in different units: an offset is typically measured in “one metric ton of
CO2-equivalent emissions,” while a REC is measured in “1 [megawatt-hour] of
renewable electricity.” 57 Although the EPA has not considered AB 1305’s definition of a
“voluntary carbon offset,” its explanation of why offsets and RECs are different “tools in
[the] sustainability tool box” is consistent with our analysis. 58 For these reasons, we
conclude that RECs used outside of the State’s regulatory programs are not “voluntary
carbon offsets” under AB 1305.
54
See, e.g., Pub. Util. Code, § 399.25, subd. (c) (requiring the California Energy
Commission to establish a system for tracking RECs that “verifies the [associated]
generation of electricity” and “protects against multiple counting”); compare, e.g.,
Assembly Analysis, at p. 2 (“[V]oluntary carbon offset credits sold to consumers or
businesses to voluntarily offset their emissions are completely unregulated”).
55
EPA Offsets and RECs, at pp. 1, 5.
56
EPA Offsets and RECs, at p. 5.
57
EPA Offsets and RECs, at p. 5.
58
EPA Offsets and RECs, at p. 5; see, e.g., Wildlife Alive v. Chickering (1976) 18 Cal.3d
190, 201 (treating “administrative interpretation” of federal environmental law as
“persuasive authority” in interpreting analogous state law).
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