Environmental Protection Agency administrator Lisa Jackson announced Thursday she’ll be stepping down. Wisconsin environmental groups say they’re sorry to see her leave.Jackson’s legacy includes reducing mercury pollution from coal power plants and setting stricter carbon emission standards for new coal plants.

Wisconsin Environment State Advocate Megan Severson says Jackson also helped raise the fuel economy standard for cars to 54.5 miles per gallon by 2025, “Which is actually the single biggest step that the federal government has taken to tackle global warming and will be about the equivalent of taking 600,000 cars off the road every year.”

Jackson has been criticized by some environmental leaders, who say the Obama administration isn’t doing enough to address climate change.

Clean Wisconsin Senior Policy Director Keith Reopelle says Jackson’s actions have done a lot to reduce smog and soot, although he says the EPA has been slow in drafting certain carbon pollution rules. Reopelle says looking forward, he hopes the next EPA administrator will more strongly enforce the Clean Water Act, “The requirements under the Clean Water Act, to reduce phosphorous and polluted runoff into the Mississippi River and the Great Lakes and the other major waterways in Wisconsin.”

The Nature Conservancy’s Wisconsin Director of Government Relations Todd Holschbach says Jackson was a strong leader during an overly politicized time for the EPA. He commends her work on the Great Lakes Restoration Initiative, which invests money in cleaning up toxins and fighting invasive species.