Global green wave shifts north and east more quickly

What the study found: The global "green wave" centroid, a satellite-based measure of vegetation phenology, moves northward during both boreal and austral summer. The study also found that the trajectory's eastward shift is accelerating.
Why the authors say this matters: The authors conclude that tracking the green wave's centroid can show how regionally changing land dynamics affect the global functioning of Earth's terrestrial biosphere.
What the researchers tested: The researchers proposed a way to quantify global phenology by tracking the centroid of the green wave using satellite data and Earth system model data. They compared the observed trajectory with expectations based on earlier reports of global greening.
What worked and what didn't: The northward shift occurred in both summer periods, and the austral summer shift was consistently larger than the boreal summer shift across datasets. As a result, the amplitude of the green wave trajectory is decreasing, and the abstract says this trend is projected to intensify throughout this century. Contrary to the original expectation, the trajectory did not show a rapid northward shift in boreal summer and only a moderate southward shift in austral summer.
What to keep in mind: The abstract does not describe detailed limitations or uncertainty ranges. It also refers to projections for this century without giving the specific model settings in the summary provided.

Key points

• The green wave centroid moves northward during both boreal and austral summer.
• The austral summer northward shift is consistently larger than the boreal summer shift across datasets.
• The trajectory's amplitude is decreasing, and the abstract says this trend is projected to intensify this century.
• The study detected an accelerating eastward shift that had not been reported before.
• The authors say tracking the centroid can help show how land dynamics affect the terrestrial biosphere.