Climate Sols. v. State

FILE THIS OPINION WAS FILED FOR RECORD AT 8 A.M. ON SEPTEMBER 17, 2026 IN CLERK’S OFFICE SUPREME COURT, STATE OF WASHINGTON SARAH R. PENDLETON SEPTEMBER 17, 2026 SUPREME COURT CLERK IN THE SUPREME COURT OF THE STATE OF WASHINGTON CLIMATE SOLUTIONS; NO. 104240-0 WASHINGTON CONSERVATION ACTION; FRONT AND CENTERED; EN BANC WASHINGTON SOLAR ENERGY INDUSTRIES ASSOCIATION; THE SIERRA CLUB; WASHINGTON PHYSICIANS FOR SOCIAL Filed: September 17, 2026 RESPONSIBILITY; KING COUNTY, a Washington municipal corporation; CITY OF SEATTLE, a Washington municipal corporation; ANTHONY MASCHMEDT; DWELL DEVELOPMENT, Respondents, v. STATE OF WASHINGTON; BUILDING INDUSTRY ASSOCATION OF WASHINGTON; ASHLI PENNER, Appellants. STEPHENS, C.J.—The people of Washington have the authority to propose and pass legislation through initiative, subject to constitutional limitations. WASH. CONST. art. II, §§ 1, 19. This case concerns Initiative 2066 (I-2066), which was approved by Washington voters in the November 2024 general election. I-2066 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 impacts Washington law in several ways. It prevents all local governments, and some utilities, from taking any action that discourages or prohibits natural gas; it broadly inhibits the authority of local air quality regulators; it removes several specific zero-emission goals from state law; it rolls back certain decarbonization efforts while also amending the Washington Decarbonization Act for Large Combination Utilities, ch. 80.86 RCW; and it prevents the state building council from taking any action to discourage gas usage or from taking certain actions to promote the transition away from all fossil fuels. A group called Climate Solutions, joined by several organizations and government entities, challenged the constitutionality of I-2066 under article II, sections 19 and 37 of the Washington Constitution. The King County Superior Court invalidated the initiative in its entirety, holding that it impermissibly encompasses more than one subject, fails to include its subjects in the title, and fails to set forth the laws it amends. We affirm on narrower grounds. We hold that I-2066 violates the single- subject requirement contained in article II, section 19. Because the provisions that introduce distinct subjects are not severable, I-2066 is unconstitutional in its entirety. BACKGROUND In November 2024, Washington voters approved I-2066 with the following ballot title: 2 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 Initiative Measure No. 2066 concerns regulating energy services, including natural gas and electrification. This measure would repeal or prohibit certain laws and regulations that discourage natural gas use and/or promote electrification, and require certain utilities and local governments to provide natural gas to eligible customers. Clerk’s Papers (CP) at 636. The legislative title for I-2066 describes the measure as “AN ACT Relating to promoting energy choice by protecting access to gas for Washington homes and businesses.” CP at 654. I-2066 is 21 pages long and contains 13 sections, which may be grouped into several categories. First, some sections enact new requirements for entities primarily responsible for delivering and regulating the demand and supply of natural gas—local governments, utility providers, and the Utilities and Transportation Commission (UTC). I-2066 requires these entities to ensure consumers have access to natural gas, regardless of the availability of other energy sources. I-2066, §§ 2-5. It achieves this by enacting new requirements and repealing sections of the Decarbonization Act that would have mandated or incentivized the electrification of Washington’s energy infrastructure. Id. Second, some sections regulate the goals and standards governing the Washington State Building Code Council and all new construction across the state. Id. §§ 6-8. For example, section 6 removes a stated construction goal from Washington’s energy code that was aimed at achieving zero greenhouse gas 3 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 emission homes and buildings by 2031. Id. § 6(2)-(3). Sections 6, 7, and 8 prevent the state building code council from amending the state energy code or the state building code in any way that would prohibit, penalize, or discourage the use of gas as a form of heating or for appliance or equipment uses. Id. §§ 6-8. Third, I-2066 places broad restrictions on the authority of cities, towns, counties, and local air pollution control agencies. It prevents these local entities from taking any action to prohibit, penalize, or discourage the use of gas for any form of heating, or for uses related to any appliance or equipment, in any building. Id. §§ 9-11. Finally, I-2066 amends several existing laws, repealing, for example, the Decarbonization Act’s severability clause as well as legislative findings on clean energy, emissions reductions, and electrification. Id. § 12. Climate Solutions and several other entities (collectively Climate Solutions) filed this action in King County Superior Court, alleging that I-2066 is unconstitutional on several grounds. Climate Solutions argued that I-2066 violates the “single-subject” and “subject-in-title” requirements contained in article II, section 19 and silently amends other laws in violation of article II, section 37. The State of Washington, joined by intervenors the Building Industry Association of Washington and Ashli Penner (collectively BIAW), defended the constitutionality of the initiative. The parties filed cross motions for summary judgment. 4 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 The trial court granted Climate Solutions’ motion for summary judgment, declaring I-2066 unconstitutional in its entirety on all grounds presented. The State and BIAW appealed directly to our court, and we granted review. 1 ANALYSIS Unlike Congress, whose powers must be enumerated in the United States Constitution, state legislatures possess broad, plenary police power, with our state constitution placing express restraints on that power. THOMAS M. COOLEY, A TREATISE ON THE CONSTITUTIONAL LIMITATIONS WHICH REST UPON THE LEGISLATIVE POWER OF THE STATES OF THE AMERICAN UNION 207 (5th ed. 1883); State v. Gunwall, 106 Wn.2d 54, 66, 720 P.2d 808 (1986) (“[O]ur state constitution imposes limitations on the otherwise plenary power of the state to do anything not expressly forbidden by the state constitution or federal law.”). The people’s legislative power to enact law through popular initiative is subject to the same constitutional restraints as applied to bills passed by the legislature. WASH. CONST. art I, § 1 (“All political power is inherent in the people.”); City of Burien v. Kiga, 144 Wn.2d 819, 824, 31 P.3d 659 (2001) (“In approving an initiative measure, the 1 We accepted amici briefs from several organizations and elected officials: Associated Builders and Contractors of Western Washington et al.; former Governor Jay Inslee, Senator Rebecca Saldaña, Representative Beth Doglio, and Representative Joe Fitzgibbon (collectively Officials); Heating, Air Conditioning, and Refrigeration Distributors International; Master Builders Association of King and Snohomish Counties; Northwest Hearth, Patio & Barbecue Association; Physicians for Social Responsibility et al.; Washington Aggregates & Concrete Association; Washington Food Industry Association et al.; Association of Washington Business; and Washington State Building Code Council. 5 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 people exercise the same power of sovereignty as the Legislature when enacting a statute.”). Article II, section 19 is among the constitutional provisions that operate to restrain the legislature’s otherwise plenary power. Union High Sch. Dist. No. 1 v. Taxpayers of Union High Sch. Dist. No. 1, 26 Wn.2d 1, 7, 172 P.2d 591 (1946). It provides that “[n]o bill shall embrace more than one subject, and that shall be expressed in the title.” WASH. CONST. art II, § 19. This provision contains “two distinct prohibitions.” Amalg. Transit Union Loc. 587 v. State, 142 Wn.2d 183, 207, 11 P.3d 762 (2000). The first is that “no bill shall embrace more than one subject,” and the second is that “no bill shall have a subject that is not expressed in the title.” Lee v. State, 185 Wn.2d 608, 620, 374 P.3d 157 (2016). We generally refer to the first as the “single-subject” requirement and the second as the “subject-in-title” requirement. This limitation on legislative power “protect[s] serious constitutional interests,” and its purposes are “threefold.” Patrice v. Murphy, 136 Wn.2d 845, 851, 966 P.2d 1271 (1998); State ex rel. Wash. Toll Bridge Auth. v. Yelle, 32 Wn.2d 13, 24, 200 P.2d 467 (1948). First, it prevents “logrolling,” the impermissible practice of attaching unpopular provisions addressing one subject to more popular, but unrelated, provisions to increase their likelihood of enactment. Garfield County Transp. Auth. v. State, 196 Wn.2d 378, 387, 473 P.3d 1205 (2020); see also COOLEY, 6 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 supra, at 172 (describing the practice of “logrolling” as “one both corruptive of the legislator and dangerous to the State”). Second, it prevents hidden subjects from being enacted into law without being properly scrutinized by those responsible for their enactment. Garfield, 196 Wn.2d at 387. Relatedly, it serves the broader interest of political transparency by allowing the public to understand and engage with the contents of proposed laws, whether they be initiatives or bills introduced in the legislature. Id. I. The Constitutionally Permissible Scope of a Legislative “Subject” Is Broad but Not Unlimited Our constitutional single-subject inquiry begins by determining whether a measure’s title is “general or restrictive,” and the subsequent analysis of its subject is guided by this determination. Filo Foods, LLC v. City of SeaTac, 183 Wn.2d 770, 782, 357 P.3d 1040 (2015). We look first at the wording of the ballot title, but we examine the measure in its entirety to ensure it embraces only a single subject. State ex rel. Wash. Toll Bridge Auth. v. Yelle, 61 Wn.2d 28, 32, 377 P.2d 466 (1962) (examining whether legislation contained only its “general subject in both the title . . . and in the body of the act” (emphasis added)). A general title is “broad, comprehensive, and generic as opposed to a restrictive title that is specific and narrow.” Kiga, 144 Wn.2d at 825. We liberally construe general titles, recognizing the need for legislation to encompass incidental topics so long as there is “‘some 7 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 rational unity between the general subject and the incidental subdivisions.’” Wash. Ass’n for Substance Abuse & Violence Prevention v. State, 174 Wn.2d 642, 656, 278 P.3d 632 (2012) (internal quotation marks omitted) (quoting State v. Grisby, 97 Wn.2d 493, 498, 647 P.2d 6 (1982)). Still, liberal construction is not a rubber stamp, and we have invalidated several enactments with general titles when they encompassed more than one subject. Amalg. Transit Union, 142 Wn.2d at 217 (holding that an initiative with a general title violated article II, section 19 because “there is no rational unity between the subjects”); Garfield, 196 Wn.2d at 387 (“[W]e do not shirk from our responsibility to enforce the constitution’s mandates.”). In examining the relationship among the provisions of a bill or initiative, our “rational unity” inquiry requires there be unity “among all matters included within the measure and the general topic expressed in the title.” Kiga, 144 Wn.2d at 826 (emphasis added); Amalg. Transit Union, 142 Wn.2d at 212 (“[R]egardless of what is in the Voters Pamphlet or the history of the initiative, the rational relationship inquiry centers on what is in the measure itself, i.e., whether the measure contains unrelated laws.”). It is not sufficient that all provisions rationally relate to the general title; there must also be rational unity among the provisions. Stated differently, the single-subject requirement in article II, section 19 demands both horizontal rational unity, i.e., all provisions rationally relate to one another, and vertical rational unity, i.e., each provision rationally relates to the general title. See, 8 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 e.g., Barde v. State, 90 Wn.2d 470, 472, 584 P.2d 390 (1978) (holding a legislative enactment violated article II, section 19 because two provisions did not share rational unity despite nominally appearing to “both relate to personal property”); Amalg. Transit Union, 142 Wn.2d at 217 (invalidating an initiative because it contained “no rational unity between the subjects” and “neither subject is necessary to implement the other”). Here, the parties do not dispute that I-2066’s title is general in nature. CP at 640; Resp’ts’ Br. at 20; Br. of Appellants-Intervenors BIAW at 20; Br. of Appellant State of Wash. at 17-19. We agree, as the title is sufficiently “broad, comprehensive, and generic” to be categorized as general. Kiga, 144 Wn.2d at 825. To satisfy the requirements of article II, section 19, all of I-2066’s provisions must have horizontal rational unity with one another and vertical rational unity with its general title. Rational unity involves a fact-specific inquiry, and our prior applications of the rule are instructive. We have often found it permissible for legislation containing a general title to regulate incidental subjects within a larger subject. For example, an initiative did not violate the single-subject requirement when it addressed two distinct methods of “trapping and killing mammals” because each method had rational unity with the others and with the general title. Citizens for Responsible Wildlife Mgmt. v. State, 149 Wn.2d 622, 639, 71 P.3d 644 (2003). Another initiative permissibly contained 9 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 a provision repealing a law that authorized certain deductions by state employees for political committee donations. Wash. Fed’n of State Emps. v. State, 127 Wn.2d 544, 548, 901 P.2d 1028 (1995). We found a “rational nexus” between this provision and the ballot’s general title2 because its primary purpose was to “eliminate[] one method of making contributions to political committees” and, by extension, political campaigns. Id. at 557. We determined that repealing this authorization was reasonably related to the subject of limiting campaign contributions. More generally, we have reasoned that provisions necessary to the implementation of one another are generally rationally related. See Wash. Ass’n of Neigh. Stores v. State, 149 Wn.2d 359, 370, 70 P.3d 920 (2003), abrogated in part on other grounds by Filo Foods, 183 Wn.2d at 782 n.4; cf. Citizens for Responsible Wildlife, 149 Wn.2d at 638 (“An analysis of whether the incidental subjects are germane to one another does not necessitate a conclusion that they are necessary to implement each other, although that may be one way to do so.”). History and context matter. When the legislature has historically paired issues together in legislation, that past practice provides strong evidence of horizontal rational unity for single-subject purposes. Wash. Ass’n for Substance Abuse, 174 Wn.2d at 657. For example, this court found no single-subject violation in an 2 The ballot title in that case asked, “‘Shall campaign contributions be limited; public funding of state and local campaigns be prohibited; and campaign related activities be restricted?’” Wash. Fed’n of State Emps., 127 Wn.2d at 555 (quoting court papers). 10 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 initiative that earmarked general public safety funds for use by local governments as part of a broader enactment regulating liquor because “liquor has an obvious connection to broader public safety concerns than might feasibly be addressed by a more limited earmark.” Id. (determining that “the legislature’s recognition of the relationship between liquor regulation and public welfare supports [the] finding that these issues share rational unity”). Thus, while the subject of public safety could be seen as distinct from liquor regulation, in this historical context, rational unity was present because the legislature had long regulated those two subjects together. Finally, our rational unity analysis considers the substance of legislation. We give latitude to precatory language in policy expressions (“policy fluff”), even when it is unrelated to the title or to other provisions because such provisions are not legally operative. Pierce County v. State, 150 Wn.2d 422, 435-36 78 P.3d 640 (2003) (“[P]recatory language cannot yield additional ‘subjects’ for article II, section 19 purposes.”). In considering past bills and initiatives, we have consistently concluded that enactments violate the single-subject requirement when their provisions have distinct regulatory effects because of the lack of rational unity between such provisions. For example, we invalidated an initiative that contained separate provisions for both a one-time action (authorization to build a road) and a broader systematic change in the law (establishing and operating a system of toll roads). 11 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 Wash. Toll Bridge Auth. v. State, 49 Wn.2d 520, 521-25, 304 P.2d 676 (1956). Similarly, in Kiga, we invalidated an enactment that combined a one-time nullification and refund of taxes with systematic changes to the property tax assessment system. 144 Wn.2d at 827. We noted that “[t]he broad language of the repeal and refund provision effectively implicates utility charges, hospital charges, housing authority rents, city moorage rates, park district admissions, port district cold storage charges, and numerous other ‘monetary charges.’” Id. Though the provision was a one-time action, its effects were far more widespread than the ongoing, focused changes the initiative made to the way in which property taxes were to be assessed. Id.; see also Citizens for Responsible Wildlife, 149 Wn.2d at 637 (noting that when one provision is “more broad, long term and continuing than the other, [it] suggests logrolling may be at issue”). Our analysis further considers purpose in identifying legislative subjects. In Amalgamated Transit Union, we invalidated an initiative that had “two purposes: to specifically set license tab fees at $30 and to provide a continuing method of approving all future tax increases.” 142 Wn.2d at 217. One provision repealed a tax as the means through which to implement $30 license tab fees while the other created a voter approval requirement for future taxes. Both provisions nominally involved taxes, but we recognized that the enactment’s two purposes lacked what may be called horizontal rational unity because their primary purpose differed substantially. 12 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 See id. at 216-17 (“Further, neither [provision] is necessary to implement the other.”). Finally, in Garfield, we held that enactments joining together separate provisions with unrelated local and statewide effects lack horizontal rational unity. 196 Wn.2d at 397. Specifically, we determined that an initiative limiting vehicle taxes and fees violated the single-subject rule by also including an errant specific directive requiring Sound Transit to retire, refinance, or sell certain bonds. Id. at 393. We concluded that the specific directive to a “single regional transportation district” added a separate subject to provisions with otherwise statewide effects on motor vehicle excise taxes. Id. at 396-97 (describing the single-subject problem as “combining a requirement to retire, defease, or refinance existing bonds that secure a specific existing project with more general statutory changes”). II. I-2066 Violates the Single-Subject Requirement Contained in Article II, Section 19 of the Washington Constitution This matter is before us on review of the superior court’s order granting summary judgment to Climate Solutions and invalidating I-2066. We review a trial court’s grant of summary judgment de novo. Id. at 386. We presume initiatives, as legislative enactments, are constitutional and the challenger must convince the court with “argument and research” that “after a searching legal analysis, . . . the statute 13 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 violates the constitution.”3 Island County v. State, 135 Wn.2d 141, 147, 955 P.2d 377 (1998); Garfield, 196 Wn.2d at 386. Rules of statutory construction apply to initiatives, and the court’s purpose is to discern and effectuate the intent of the voters “acting in their legislative capacity.” Amalg. Transit Union, 142 Wn.2d at 205. We read initiatives to the people “as the average informed lay voter would read them,” giving words their ordinary meaning and avoiding technical or specialized legal constructions. Garfield, 196 Wn.2d at 386. As with statutes enacted by the legislature, it is not our role to substitute our perceived “‘better judgment’” for that of the voters, and, just as importantly, we will not strain to construe otherwise unconstitutional enactments as valid based on policy preferences. Amalg. Transit Union, 142 Wn.2d at 206 (quoting Fritz v. Gorton, 83 Wn.2d 275, 287, 517 P.2d 911 (1974)). Drawing on our precedent and the principle expressed in the single-subject requirement of article II, section 19, we consider the specific provisions of I-2066. While the parties agree that I-2066 bears a general title, they do not agree on what 3 At times, we have described the standard of review as requiring a challenger to demonstrate that a statute is unconstitutional “beyond a reasonable doubt.” This is not an evidentiary standard but rather a “reflection of ‘respect for the legislature’” insofar as duly enacted legislation is a direct expression of the people’s will. Quinn v. State, 1 Wn.3d 453, 471 n.9, 526 P.3d 1 (2023) (quoting Sch. Dists.’ All. for Adequate Funding of Special Educ. v. State, 170 Wn.2d 599, 606, 244 P.3d 1 (2010)). “‘Beyond a reasonable doubt’ in this context merely means that . . . we will not strike a duly enacted statute unless we are ‘fully convinced, after a searching legal analysis, that the statute violates the constitution.’” Sch. Dists., 170 Wn.2d at 606 (quoting Island County v. State, 135 Wn.2d 141, 147, 955 P.2d 377 (1998)). 14 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 constitutes the initiative’s subject. The State formulates the subject as protecting natural gas access and use, while BIAW argues that the initiative has a broader subject, “preserving energy choice,” which encompasses the State’s formulation of the subject. The State and BIAW argue that both of their proposed subjects encompass incidental subjects designed to ensure demand for and supply of natural gas. Climate Solutions disagrees, arguing that “I-2066 combines at least six distinct subjects,” which include natural gas access but also “air pollution regulation, building codes, and utility ratemaking, [while also] reshaping policies for fossil fuels of all types.” Resp’ts’ Br. at 22-23. We have long recognized that though it is permissible for initiatives with general titles to encompass incidental subjects, this flexibility is not unlimited. I- 2066 regulates several discrete subjects because it includes provisions with substantially distinct regulatory effects, e.g., requiring statewide natural gas access and use, limiting local authority over air quality standards, amending statewide building codes, and repealing the Decarbonization Act’s severability clause. These distinct subjects encompass a wide range of issues through provisions with distinct regulatory effects, resulting in a lack of rational unity under article II, section 19.4 4 Justice Mungia’s dissent describes the “first step in the rational unity analysis [as] examining the subject expressed in the initiative’s title and its scope.” Dissent at 7. Our precedent holds otherwise, recognizing that article II, section 19 requires all provisions of an enactment to share rational unity with one another and with the enactment’s general title. See, e.g., Barde, 90 Wn.2d at 472 (finding that the provisions did not rationally relate to one another and thus the 15 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 First, I-2066 ensures that natural gas must be accessible to any consumer who wants to use it as an energy source. Sections 2, 3, and 4 of the initiative require gas companies, large combination utilities, and certain cities or towns to provide natural gas to eligible consumers in their service areas while simultaneously preventing UTC from approving rate plans that might act to restrict such access. This affirmative responsibility is broad in its application but narrow in its subject matter. Put simply, it seeks to ensure a steady supply of natural gas by directly regulating the entities responsible for its delivery to consumers. Second, section 11 of I-2066 addresses the subject of air quality by adding a provision to Washington’s Clean Air Act, ch. 70A.15 RCW, that prohibits air pollution control agencies from “in any way prohibit[ing], penaliz[ing], or discourag[ing] the use of gas for any form of heating, or for uses related to any appliance or equipment, in any building.” CP at 674-75. The State and BIAW frame the changes to Clean Air Act emission goals as necessary to remove impediments to natural gas demand and supply, but this is belied by the fact that these amendments have distinct primary purposes and far-reaching effects. As amici point out, “Under the Initiative’s amendment, local authorities may no longer implement any of Ecology’s emissions standards relating to gas in buildings as any such standards may enactment violated the single-subject rule); Amalg. Transit Union, 142 Wn.2d at 217 (same). Determining whether such rational unity exists necessitates looking at both the general title and the body of the law at issue. 16 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 be deemed to ‘discourage’ the use of gas.” Br. of Amici Curiae Offs. at 33-34. Another amici’s brief explains how “[a]ppliances that burn gas also release multiple other air pollutants, including nitrogen dioxide (NO2), carbon monoxide (CO), fine particulate matter (PM2.5), ultrafine particulate matter (UFP), and carcinogens such as formaldehyde, benzene, and toluene, which are hazardous air pollutants.” Amicus Curiae Br. of Physicians for Soc. Responsibility et al. at 7-8. Section 11’s primary effect is that an air pollution control agency is powerless to prevent the health effects of any emissions that are produced by any appliance, system, or building that might conceivably burn gas. This restraint creates a glaring loophole in the Clean Air Act by substantially limiting the authority of enforcement entities to regulate air quality in any manner that could “in any way” discourage the use of gas. While BIAW argues that the legislature has a long history of regulating the supply and demand of energy in one piece of legislation, they fail to identify examples of the legislature regulating the demand and supply of energy together with substantial restraints on the authority of air pollution control agencies. Instead, they rely on an overly broad construction of demand and supply to include such subjects in its ambit. Air pollution control agencies are not, however, responsible for regulating or controlling the demand and supply of energy. Instead, their actions only incidentally affect an individual’s right to burn natural gas—and any other fossil fuel—through the imposition of regional air quality standards. Like in Barde, the fact that two 17 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 provisions are nominally related does not mean that they share the required horizontal rational unity. 90 Wn.2d at 472 (noting that while two provisions “both relate[d] to personal property” and thus shared a nominal similarity, there was no rational unity between them because the direct operative effect of each provision differed); see also Amalg. Transit Union, 142 Wn.2d at 217 (finding two provisions lacked rational unity because of their distinct regulatory effects even though both nominally dealt with taxes). We agree with Climate Solutions that if air quality standards fall within the scope of regulating demand and supply, then “virtually any provisions that inconvenience or increase the cost of natural gas—taxes on gas appliances, workplace or pipeline safety rules, consumer protection disclosures about carbon monoxide risks, or even zoning setbacks for gas infrastructure—could be swept into the same measure.” Resp’ts’ Br. at 26. Article II, section 19 demands rational unity among a measure’s provisions and does not contemplate so broad a scope. Because Section 11’s targeted and total restraint on the authority of local air quality regulators to regulate all fossil fuels has a distinct primary purpose from regulating the demand and supply of energy, as well as broader effects, it introduces a separate subject. Third, I-2066 repeals zero-emissions goals in the state energy code and restricts the state building code council from taking any action to limit access to gas. Specifically, section 6 repeals sections of the “Washington State Energy Code” that 18 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 were designed to “help achieve the broader goal of building zero fossil-fuel greenhouse gas emission homes and buildings.” CP at 671 (strikethrough omitted). It also prohibits statewide energy and building codes from enacting provisions or taking actions that “in any way prohibit, penalize, or discourage the use of gas.” Id. The primary regulatory effect of these provisions is to broadly limit the authority of Washington’s statewide building code council and to require statewide changes to construction standards, a constitutionally distinct subject from requiring local entities to provide natural gas and restricting the authority of local air quality regulators. Finally, I-2066 amends the Decarbonization Act, including by repealing its severability clause. The State and BIAW argue that repealing a severability clause does not introduce a separate subject because such a change lacks any legal effect. We disagree. The repeal of a severability clause is not the same as mere “policy fluff,” which does not create a distinct subject. Pierce County, 150 Wn.2d at 435- 36. A policy statement lacks legal effect by definition. Id. In contrast, a severability clause has a clear legal effect, and it is immaterial that “[s]everability clauses become relevant only after a court holds ‘invalid’ one or more provisions of a larger act.” Reply Br. of Appellants-Intervenors BIAW at 11 (quoting Amalg. Transit Union, 142 Wn.2d at 228). A severability clause plays a role in our assessment of whether a statute constitutes an integrated whole or comprises severable parts and thus has 19 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 legal effect. El Centro De La Raza v. State, 192 Wn.2d 103, 132, 428 P.3d 1143 (2018) (plurality opinion) (“[W]hen legislation includes a severability clause, it ‘provide[s] the necessary assurance that the Legislature would have enacted the appropriate sections of the legislation despite the unconstitutional sections.’” (second alteration in original) (quoting Gerberding v. Munro, 134 Wn.2d 188, 197, 949 P.2d 1366 (1998))). All provisions of an initiative must share horizontal rational unity with one another and vertical rational unity with the general subject. Kiga, 144 Wn.2d at 826. Repealing the Decarbonization Act’s severability clause lacks rational unity with the other subjects we have identified because it has a distinct regulatory purpose. III. I-2066 Is Not the Unique Type of Comprehensive “Omnibus Legislation” Addressed in In Re Boot In an effort to justify I-2066’s wide-ranging provisions, the State and BIAW point to cases where the “Legislature [has] found it necessary to combine diverse provisions into a single omnibus act to address a single problem in a comprehensive way.” In re Boot, 130 Wn.2d 553, 568, 925 P.2d 964 (1996) (emphasis added) (holding that a 213-page bill with 190 sections did not violate the single-subject requirement). We take this opportunity to clarify that article II, section 19 does not contain an explicit exception for omnibus legislation. Rather, all provisions of a bill or initiative must have “rational unity” to the general subject and to one another. 20 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 However, given the fact-specific nature of our single-subject inquiry, whether diverse provisions in omnibus legislation have rational unity depends on the breadth of the problem and the comprehensive nature of the effort required to address it. In re Boot examined an amendment to the Basic Juvenile Court Act, enacted as part of the omnibus violence prevention act of 1994. LAWS OF 1994, 1st Spec. Sess., ch. 7. This enactment covered “a number of issues, including public health, community networks, firearms and other weapons, public safety, education, employment, and media.” In re Boot, 130 Wn.2d at 565-66. We held that while the Act “covers a variety of subjects,” these subjects share rational unity because the “Legislature found it necessary to combine diverse provisions into a single omnibus act to address a single problem,” violence prevention, “in a comprehensive manner.” Id. at 566, 568. Because the problem to be addressed was broadly described and comprehensively addressed, the bill was consistent with the single-subject requirement of article II, section 19. Similarly, in Doriot v. State, the Court of Appeals held that in crafting legislation in the face of a complex, multifaceted problem such as transportation resources, the legislature could rationally use a comprehensive approach incorporating diverse incidental subjects aimed at directly addressing that problem. 32 Wn. App. 2d 770, 774, 783, 561 P.3d 1208 (2024) (finding a 121-page omnibus transportation bill did not violate article II, section 19, because it “reflects the legislature’s effort to address a single problem, transportation 21 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 resources, in a comprehensive manner”). Indeed, we have found omnibus legislation to be consistent with the single-subject requirement precisely because it comprehensively tackles a single problem in contrast to legislation addressing only a specific part of a problem that does not rationally incorporate such diverse and attendant subjects. I-2066 is not omnibus legislation under our precedent because it does not address “a single problem . . . in a comprehensive manner.” In re Boot, 130 Wn.2d at 568. Even if we accept BIAW’s contention that the broad issue I-2066 seeks to address is “preserving energy choice,” Br. of Appellants-Intervenors BIAW at 1, the measure is nowhere near as comprehensive as the violence prevention enactment in In re Boot or the transportation legislation in Doriot. Rather, in patchwork fashion, I-2066 sets out several discrete policy measures, with sections that govern the provision and use of natural gas by utilities, remove zero-emission goals, restrict local government authority, and enact statewide reforms to building and energy codes. These sections operate separately and do not comprehensively regulate energy choice for the people of Washington. Even if we were to narrow the scope of the issue I-2066 addresses and accept the State’s contention that the initiative seeks only to protect natural gas access and use, I-2066 still does not comprehensively address this issue. For example, I-2066 restricts local government, utility, and local air pollution control authority over natural gas supply and 22 Climate Solutions, et al. v. State of Washington, et al., No. 104240-0 emissions, but it does not address the statewide regulation of natural gas supply and demand. Instead, I-2066’s diverse provisions enact distinct policies with discrete regulatory effects and therefore do not share rational unity as “omnibus legislation.” Because I-2066 combines them in one initiative, we find that it violates the single- subject rule contained in article II, section 19. IV. It Is Impossible To Sever the Provisions of I-2066 That Violate the Single- Subject Rule, and Therefore the Entire Initiative Is Unconstitutional Under Article II, Section 19 I-2066 is not amenable to severance, despite the initiative drafters’ inclusion of a severability cl