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Carbon dioxide (CO₂) in 1999 (global mean)
Annual mean367.79 ppm
vs previous year+2.10 ppm
Rank of increase19 / 46
Max − min within year3.96 ppm
By month
| Month | Concentration | vs same month last year |
|---|---|---|
| Jan | 368.11 ppm | +2.92 |
| Feb | 368.51 ppm | +3.04 |
| Mar | 368.90 ppm | +2.97 |
| Apr | 369.29 ppm | +2.71 |
| May | 369.21 ppm | +2.35 |
| Jun | 368.36 ppm | +2.10 |
| Jul | 366.69 ppm | +1.86 |
| Aug | 365.33 ppm | +1.54 |
| Sep | 365.45 ppm | +1.42 |
| Oct | 366.75 ppm | +1.41 |
| Nov | 368.04 ppm | +1.44 |
| Dec | 368.88 ppm | +1.41 |
+1.49 ppm
+1.85 ppm
+1.76 ppm
+1.10 ppm
+2.66 ppm
+2.10 ppm
+1.17 ppm
+1.60 ppm
+2.02 ppm
+2.56 ppm
+1.81 ppm
Bars: yearly increase in the surrounding years. NOAA GML global monthly means.