Table 1. Global mean percentage change.

Table showing the global mean percentage change and the associated standard errors of the mean for ${\text{N}}_{200}^2$, N², and the mixed-layer depth (MLD). Local trend estimates at each grid point are divided by the local climatological mean value, and the global mean and standard error of the global mean are then computed. Standard error is computed by propagating the local standard error produced by the regression method (see Methods; Extended Data Fig. 4).

(% dec-1)	Choice 1	Choice 2	Mean
${\text{N}}_{200}^2$	1.5±0.2	1.1±0.3	1.3±0.3
N2	9.5±4.4	8.3±0.9	8.9±2.7
MLD	-2.6±0.1	-3.2±0.9	-2.9±0.5