Virginia cannot withdraw from a multistate initiative designed to reduce greenhouse gas emissions unless the Legislature agrees to it, a judge ruled, dealing a blow to Gov. Glenn Youngkin’s efforts to leave the pact.

The ruling, issued Monday by retired Floyd County Judge C. Randall Lowe, says the Virginia Air Pollution Control Board exceeded its authority when it voted last year to opt out of the Regional Greenhouse Gas Initiative.

The Regional Greenhouse Gas Initiative is an effort by 12 states in the Mid-Atlantic and Northeast to reduce carbon emissions from power plants. Participating states require power plants with a certain production capacity to purchase allowances to emit carbon dioxide, a greenhouse gas that contributes to global warming.

Virginia joined the compact in 2020 when it had a Democratic governor as well as Democratic control of the Legislature. In 2021, Youngkin, a Republican, won the gubernatorial election, but one or both legislative chambers remained under Democratic control for his entire term.

Youngkin said Virginia’s participation in the cap-and-trade program amounts to a hidden tax on Virginians’ energy bills.

His spokesman, Christian Martinez, said Wednesday that the state would appeal the judge’s decision.

“Governor Youngkin remains committed to reducing the cost of living for Virginians by continuing to oppose the Regional Greenhouse Gas Initiative, which fails to effectively incentivize emissions reductions in the Commonwealth” , he said in a written statement.

Shaun Kenney, a spokesman for Republican Attorney General Jason Miyares, also expressed disappointment with the judge’s decision in a written statement, saying, “We look forward to defending on appeal the common-sense repeal of this anti- productive. »

The State Corporation Commission has estimated that the typical monthly bill could increase by $2 to $2.50 for the years 2027 to 2030.

Last year, before the pollution control board voted to end participation in the pact, Dominion Energy, the state’s largest utility, estimated it had committed about $490 million in compliance costs through the initiative and recovered approximately $267 million from customers.

Virginia House Speaker Don Scott, a Democrat, praised the judge’s decision, calling it “a victory for all Virginians, their pocketbooks and our environment.” RGGI-funded programs have helped Virginians reduce household energy costs, protect communities from floodwaters, and have played a critical role in fighting pollution and climate change.