ESRL Global Monitoring Laboratory - Mauna Loa Observatory

Measurements at the Mauna Loa Observatory stopped after the 2022 eruption of the Mauna Loa volcano, when lava flow crossed the access road and took out power lines to the facility. The observatory remains inaccessible by vehicle and without power from the local utility company.

Observatory staff has established limited solar power in four observatory buildings and restored approximately 33 percent of the measurements onsite, including the Global Monitoring Laboratory and Scripps critical CO₂ records and other atmospheric measurements.

Media can contact: Theo Stein (303) 819-7409 (theo.stein@noaa.gov) or Karin Vergoth 303-632-6413‬ (karin.vergoth@noaa.gov)

July 13, 2014

2013 State of the Climate: Carbon dioxide tops 400 ppm

On May 9, 2013, the daily average concentration of carbon dioxide (CO2) in the atmosphere surpassed 400 parts per million (ppm) for the first time at the Mauna Loa Observatory in Hawaii, where the modern record of observations began back in 1958. Other Northern Hemisphere sites also reported CO2 concentrations exceeding 400 ppm in 2013. By summer, the high concentrations at these sites had dropped as vegetation began taking up carbon dioxide for photosynthesis.

July 8, 2014

Greenhouse gases top 400 ppm for three months in a row at Mauna Loa

For the first time since carbon dioxide in the atmosphere has been measured, the levels of this greenhouse gas at Mauna Loa, Hawaii, have been above 400 parts per million every single day for three straight months.

March 21, 2014

Heat-trapping gas concentrations top 400 ppm, two months earlier than last year

Over the last five days beginning on March 16, 2014, carbon dioxide levels have surpassed 400 parts per million at NOAA's Mauna Loa Observatory in Hawaii. This is nearly two months earlier than last year when the concentration of this greenhouse gas was first recorded above 400 parts per million on May 9, at the historic NOAA observatory.

May 10, 2013

Carbon Dioxide at NOAA's Mauna Loa Observatory reaches new milestone: Tops 400 ppm

On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million (ppm) for the first time since measurements began in 1958.