The current White House doesn't accept climate science, and California is worried that this may lead to NASA switching off climate probes under pressure from President Trump. The state's solution? Build its own probe. In a speech at the Global Climate Action Summit, Governor Jerry Brown declared that California would launch its "own damn satellite" to detect pollution and address climate change. While he hinted at the possibility in 2016 remarks, it's more than just an allusion this time. The state is working with Planet Labs on the project, and will rely on the California Air Resources Board for further help.
It's not certain when this satellite might deploy or how much it would cost. And those elements are important. There may not be much point to the satellite if there's a change in White House leadership by the time the spacecraft is ready, and a satellite might face stiff opposition if it's particularly expensive.
However long it takes to finish, the project escalates the fight between California and the Trump administration. The two have been at odds since the start, and the White House even plans to revoke California's Clean Air Act waiver just to prevent it from setting tough emissions standards. The state has fired back with more than 40 lawsuits against the administration, not to mention bills to phase out fossil fuels and otherwise address climate change directly. Now, the federal government has to contend with a state-run satellite program that might challenge NASA's strategy.