The president’s budget proposal would also defund many other climate labs, including instrument sites comprising the US government’s greenhouse gas monitoring network, which stretches from northern Alaska to the South Pole.

But it’s the Mauna Loa laboratory that is the most prominent target of the President Donald Trump’s climate ire, as measurements that began there in 1958 have steadily shown CO2’s upward march as human activities have emitted more and more of the planet-warming gas each year.

In 1958, when the Keeling Curve began, the concentration of CO2 in the Earth’s atmosphere was 313 parts per million. In 2024, that had risen to 424.61 ppm, and this year, monthly average CO2 levels at Mauna Loa exceeded 430 ppm for the first time.

The proposal to shut down Mauna Loa had been made public previously but was spelled out in more detail on Monday when NOAA submitted a budget document to Congress. It made more clear that the Trump administration envisions eliminating all climate-related research work at NOAA, as had been proposed in Project 2025, the conservative blueprint for overhauling the government.