Atmospheric CO₂ (Mauna Loa) vs US Adult Obesity

Atmospheric CO₂ (Mauna Loa) and US Adult Obesity correlate at r = +0.98 over 45 years (1980–2024), p < 0.0001. With the time trend removed, r = -0.79. Direction flips without the trend.

Verdict: Direction flips without the trend. The raw correlation is 0.98, but once each series' time trend is removed it becomes -0.79. The year-to-year movements run the opposite way to the long-run trends, so the headline number is misleading.

Pearson r: +0.98
p-value: < 0.0001
Years compared (n): 45 (1980–2024)
95% confidence interval: 0.96 to 0.99
Correlation with the time trend removed: -0.79

Sources

Atmospheric CO₂ (Mauna Loa) (ppm): NOAA GML. Annual mean atmospheric carbon dioxide measured at Mauna Loa Observatory, Hawaii (NOAA GML).
US Adult Obesity (% of adults): Our World in Data. US Adult Obesity (Our World in Data: Obesity among adults, BMI >= 30 kg/m2 (crude estimate) (%) - Sex: both sexes - Age group: 18+ years of age).

Related pairs

US Adult Obesity vs US Population (r = +1.00)
Atmospheric CO₂ (Mauna Loa) vs US GDP per Capita (r = +0.99)
Atmospheric CO₂ (Mauna Loa) vs US Population (r = +0.99)
US Median Age vs US Adult Obesity (r = +0.99)
US Marriage Rate vs US Adult Obesity (r = -0.98)
US Adult Obesity vs US Resident Patent Applications (r = +0.98)

Correlation does not imply causation. How the verdict is worked out.