# Global atmospheric CO₂: annual means and growth

Dataset page: https://meplar.com/datasets/global-co2/

Snapshot: 14 October 2026. Global marine-surface measurements; chart 1980–2025; growth series 1959–2025 and annual means 1979–2025.

Full data CSV: https://meplar.com/downloads/global-co2/v1/global_co2_annual_1959_2025.csv
Chart/summary CSV: https://meplar.com/downloads/global-co2/v1/chart_data.csv
Desktop chart: https://meplar.com/downloads/global-co2/v1/chart.png
Mobile chart: https://meplar.com/downloads/global-co2/v1/chart_mobile.png
Complete package: https://meplar.com/downloads/global-co2/v1/global-co2.zip

## Package layout and reproduction

Extract the ZIP and enter meplar_energy/. This complete shared pipeline includes both nuclear/ and co2/ with their frozen raw inputs, full CSVs and reviewed chart variants. Both folders are necessary because build.py rebuilds both topics. With the versions in requirements.txt, run `python build.py`, then `python mobile.py`. No network is needed; do not run fetch_sources.py for this fixed snapshot. Rendering can depend on library/font versions; use supplied chart hashes to identify the reviewed originals.

## Source data and reuse

NOAA-produced government numerical data are in the US public domain; raw headers request source credit. Credit NOAA GML and Lan, Tans and Thoning with the cited dataset version. No NOAA endorsement is implied and no logos or third-party media are included. Original Meplar charts and code are separate works; no new license for them is asserted here.

## Original source and method notes

## Source and permission
Lan, X., Tans, P. and K.W. Thoning, Trends in globally-averaged CO2 determined from NOAA Global Monitoring Laboratory measurements, version 2026-10. https://doi.org/10.15138/9N0H-ZH07
Retrieved 2026-10-14 UTC; raw file creation timestamps 2026-10-09.
- Landing/citation: https://gml.noaa.gov/ccgg/trends/gl_data.html
- Means: https://gml.noaa.gov/webdata/ccgg/trends/co2/co2_annmean_gl.csv
- Growth: https://gml.noaa.gov/webdata/ccgg/trends/co2/co2_gr_gl.csv
- Method: https://gml.noaa.gov/ccgg/trends/gl_gr.html
- Reuse: https://www.noaa.gov/office-education/outreach-communication/faq
NOAA-produced government numerical data are public domain in the United States and freely redistributable with attribution. Raw headers expressly make the data freely available and request credit. No logos or third-party media; visualization is original.

## Cleaning and coverage
Downloaded CSVs are archived byte-for-byte in raw/, including metadata. Ignore # comment lines; rename columns; outer-join one row per year. global_co2_annual_1959_2025.csv retains all 67 growth years; means begin in 1979 and missing earlier means remain empty. No interpolation, smoothing, rescaling or outlier deletion.
chart_data.csv uses all 46 years 1980–2025. 1980 begins the modern global-network growth series; older growth uses a Mauna Loa/South Pole approximation. Partial 2026 is excluded. Highest annual mean is checked against the entire available 1979–2025 mean record.

## Dictionary
- year: calendar year.
- annual_mean_co2_ppm: NOAA global marine-surface annual mean dry-air mole fraction; ppm = micromoles CO₂ per mole of dry air.
- annual_mean_uncertainty_ppm: NOAA network-derived uncertainty. Plotted but narrower than line width.
- within_year_increase_ppm: estimated start-to-end-of-year concentration increase. NOT a percentage, emission mass or difference between consecutive annual means.
- increase_uncertainty_ppm: NOAA reported growth uncertainty (68% interval per NOAA webpage). Whiskers are value ± uncertainty.
Growth reflects net human/natural additions and removals, not fossil emissions alone. NOAA webpage and CSV describe different bootstrap ensemble sizes; we preserve supplied uncertainties without recomputing them. Latest and earlier data may be revised.

## Verified claims
2024 growth: 3.76 ± 0.11 ppm; 2025: 2.06 ± 0.08 ppm.
Reduction = (1 − 2.06 / 3.76) × 100 = 45.21276596%.
2025 annual mean 425.62 ± 0.05 ppm is highest in this 1979–2025 dataset. 2024 mean 422.79 ppm. Their difference, 2.83 ppm, is correctly NOT used as the 2025 within-year increase. Every shown increment is positive. No geological/pre-instrumental record claim.
Level line has labelled nonzero axis, 330–440 ppm; growth bars start at zero. Separate panels have explicit units and aligned coverage, no dual axis. No formal significance test is claimed.

## Reproduce
From parent directory run python build.py with requirements.txt; uses archived inputs. PNG 2800 × 2200 and SVG included. SHA256SUMS verifies files. fetch_sources.py is optional for a deliberate NEW snapshot and overwrites inputs.