The North Atlantic Oscillation (NAO), an important atmospheric phenomenon affecting the meteorology of the whole of Europe, impacts the quantity and timing of seed production in the continent's forests. When the NAO favors a dry and warm spring, most of the studied forests produced more seeds and this is also done in a more synchronized manner.
The worst scenario occurs when NAO and EA are in opposite phases. This ocurred in the first few years of the previous decade and during this period, the CO2 uptake was below average. Recently, NAO and EA were in the same phase and ecosystems have been able to remove more carbon from the atmosphere.