How much has Plant Growth Increased?
Vegetation seasonality, the opposite of plant growth, has diminished in the Northern lands by an amount equivalent to a 6 to 7 degree southward shift in latitude over the past 30 years. So, by how much did plant growth increase?
The proportion of Arctic vegetation showing increases in plant growth (greening) varied from 32 to 39% depending on the model used to assess statistical significance. The proportion showing significant decreases (browning) was less than 4%. This translates to a 10% increase in Arctic plant growth over the past 30 years.
In the Boreal region, greening varied from 34 to 41% and browning was less than 5%. This translates to a 7.5% increase in plant growth in the Boreal region over the past 30 years.
Thus, of the 26 million square kilometers of northern vegetated lands, 34 to 41% showed increases in plant growth, 3 to 5% showed decreases in plant growth, 51 to 62% showed no changes and the rest lack valid NDVI data.
The figure below shows the greening and browning discussed above. White areas correspond to vegetated lands not showing changes. Grey areas are not part of Arctic-Boreal vegetated lands considered in this study.
Larger version of this figure