update pCO2 figure

Author: oscarbranson

book/06_oceancarbon/01_3box.md

@@ -135,7 +135,7 @@ The influence of salinity is minor, with slightly higher values in fresher water
 For average surface ocean conditions of 20°C and 35 PSU, $K_0$ has a value of ~0.03.
 This means that if carbon in the oceans and atmosphere were in equilibrium, the atmosphere would contain 2255 / 0.03 = **~75,200 ppm CO<sub>2</sub>**!
 
-As of January 2024, [the atmosphere contains 422.8 ppm CO<sub>2</sub>](https://www.esrl.noaa.gov/gmd/ccgg/trends/) (up by 3.3 ppm from last year!).
+As of Feb 2026, [the atmosphere contains 428.6 ppm CO<sub>2</sub>](https://www.esrl.noaa.gov/gmd/ccgg/trends/) (up by 2 ppm from last year).
 
 ### Equilibrium?