NOAA/ESRL Trends in CO2

Monthly CO2 Update for December, 2025

Tue, 03 Feb 2026 05:01:09 MST

Recent Mauna Loa CO2
December 2025: 427.49 ppm.
Recent global CO2
October 2025: 424.54 ppm

Monthly CO2 Update for November, 2025

Mon, 05 Jan 2026 05:01:40 MST

Recent Mauna Loa CO2
November 2025: 426.46 ppm.
Recent global CO2
September 2025: 423.03 ppm

Monthly CO2 Update for October, 2025

Fri, 05 Dec 2025 05:01:29 MST

Recent Mauna Loa CO2
October 2025: 424.87 ppm.
Recent global CO2
August 2025: 422.95 ppm

Weekly CO2 Update for January 25, 2026

Tue, 03 Feb 2026 05:01:09 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on January 25, 2026: 428.39 ppm
Weekly value from 1 year ago: 427.03 ppm
Weekly value from 10 years ago: 403.08 ppm

Weekly CO2 Update for January 18, 2026

Fri, 30 Jan 2026 05:01:10 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on January 18, 2026: 428.62 ppm
Weekly value from 1 year ago: 426.88 ppm
Weekly value from 10 years ago: 402.99 ppm

Weekly CO2 Update for January 11, 2026

Fri, 23 Jan 2026 05:01:14 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on January 11, 2026: 429.15 ppm
Weekly value from 1 year ago: 426.78 ppm
Weekly value from 10 years ago: 402.79 ppm

Weekly CO2 Update for January 4, 2026

Fri, 16 Jan 2026 05:01:14 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on January 4, 2026: 428.70 ppm
Weekly value from 1 year ago: 426.20 ppm
Weekly value from 10 years ago: 402.30 ppm

Weekly CO2 Update for December 28, 2025

Fri, 09 Jan 2026 05:01:09 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on December 28, 2025: 428.26 ppm
Weekly value from 1 year ago: 426.00 ppm
Weekly value from 10 years ago: 402.35 ppm

Weekly CO2 Update for December 21, 2025

Fri, 02 Jan 2026 05:01:31 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on December 21, 2025: 427.87 ppm
Weekly value from 1 year ago: 425.62 ppm
Weekly value from 10 years ago: 402.59 ppm

Weekly CO2 Update for December 14, 2025

Fri, 26 Dec 2025 05:01:23 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on December 14, 2025: 427.22 ppm
Weekly value from 1 year ago: 425.11 ppm
Weekly value from 10 years ago: 402.61 ppm

Weekly CO2 Update for December 7, 2025

Fri, 19 Dec 2025 05:01:15 MST

Up-to-date weekly average CO2 at Mauna Loa
Week starting on December 7, 2025: 427.25 ppm
Weekly value from 1 year ago: 425.64 ppm
Weekly value from 10 years ago: 401.77 ppm

Daily CO2 Update for February 2, 2026

Tue, 03 Feb 2026 05:01:09 MST

Estimated Global Daily average CO2 trend
February 2, 2026: 427.19 ppm
Daily average CO2 at Mauna Loa
February 2, 2026: 428.24 ppm