A new bill introduced in the Washington state Legislature could make Washington the first U.S. state to tax methane emissions from livestock. The legislation, sponsored by several state Democratic lawmakers, is currently under review by Washington’s House Environment and Energy Committee.

If enacted, the bill would require dairy farms and feedlots to report their methane emissions annually, beginning the year after the law is signed. According to the legislation, collecting this data would help the state better understand its agricultural industry’s contribution to greenhouse gas emissions.

“Dairies and feed lots in the state are not currently required to report any information regarding the level of their methane emissions and, therefore, there is a notable gap in the state’s knowledge of the contribution of this industry to greenhouse gas emissions,” a portion of the bill reads.

However, the reporting requirement could lead to additional costs for local farmers. Under Washington’s Climate Commitment Act, passed in 2021, businesses emitting more than 25,000 metric tons of carbon dioxide are designated as a “major emitter” and subject to a tax. That threshold is comparable to the emissions generated by nearly 6,000 gas-powered cars in a year.

If dairy farms and feedlots exceed this limit, they could face financial penalties under state law. Republican State Rep. Joe Schmick has expressed concerns about the potential impact on Washington’s farmers.

“So, if they find that there was sufficient methane equivalent to 25,000 metric tons of CO2 emissions, these facilities would likely come under the Climate Commitment Act as covered entities,” Schmick said. “You’re asking the growers to pay more taxes, more regulation, in a time when you have record low commodity prices and their costs are astronomical right now. It’s just wrong.”

Washington’s proposal follows Denmark’s recent adoption of a similar law, which became the world’s first agricultural emissions tax. That measure, set to take effect in 2030, is expected to reduce greenhouse gas emissions by 1.8 million tons in its first year.