Rhode Island’s biggest environmental groups have ended their silence and weighed in on the fossil fuel power plant proposed for Burrillville.

In a July 21 letter to Gov. Gina Raimondo, the executive directors of Save The Bay, The Nature Conservancy, and the Audubon Society of Rhode Island state their “strong concerns regarding Invenergy’s power plant proposal.” They describe the project as “a profound threat to the natural systems and living resources our organizations seek to protect.”

They also requested a group meeting with Raimondo. Her office didn’t responded to a request for comment.

Each organization included a statement describing its stance on the natural-gas/diesel power plant.

In its statement, Save The Bay didn’t expressly oppose the nearly 1,000-megawatt power plant but instead urged the state to suspend the application process until it releases its plan to cut greenhouse gas emissions, which is expected by the end of this year.

“Climate change is caused by the burning of fossil fuels and poses profound threats to the health and resilience of Narragansett Bay,” said Jonathan Stone, executive director of Save The Bay.

The state Energy Facility Siting Board (EFSB) is reviewing the application from the developer, Chicago-based Invenergy Thermal Development LLC. Reports and other information relating to the proposed Clear River Energy Center are due by Sept. 9.

In their statements, The Nature Conservancy and the Audubon Society say they want the $700 million project stopped.

It “has not been proven necessary to meet energy needs; and it will pose unacceptable environmental risks to habitats and plant and animal species. For these reasons, The Nature Conservancy opposes the development of this power plant,” according to the organization’s statement.

While Save The Bay focuses on the health of Narragansett Bay, The Nature Conservancy and the Audubon Society are concerned about the power plant’s effects on wildlife in one of the state’s largest remaining tracts of open space, which runs the length of western Rhode Island.

Both organizations site the need to cut greenhouse gases and expand renewable energy. They also call for the state to perform a full independent study of the fossil fuel project.

In response, Invenergy said there is no reason to delay plans for the power project, which would be the largest in the state.

“Rhode Island and the rest of New England is facing a possible energy shortage in the coming years, which is in part why ISO-New England awarded the Clear River Energy Center with a capacity supply obligation,” according to Invenergy. “It’s clear that projects like ours will be an important part of the energy mix Rhode Island needs to meet demand, while also reducing carbon emissions by replacing older, more polluting power plants. At the same time, Rhode Island’s energy policy discussions will and should continue.”