(KERO) — Not even the pandemic could stop carbon dioxide levels from rising to their highest point in more than three million years last year.

The National Oceanic and Atmospheric Administration say CO-2 levels experienced their fifth largest year-over-year increase in 2020. A spokesperson for NOAA says the rise happened despite a seven-percent drop in global emissions caused by the pandemic.

The Scripps Institution of Oceanography says it took 200 years for CO-2 levels to increase 25-percent and just 30 years to reach 50-percent.