Global environmental challenges
How green is the Amazon?
Not as green as it used to be, as shown in an analysis of satellite images made during last year’s record-breaking drought.
Because greenness is an indication of health in the Amazon, a decline in this measurement means this vast area is getting less healthy — bad news for biodiversity and some native peoples in the region.
What does a drop in the greenness index look like? It looks gold, orange and red in a graphic accompanying an article to be published in the journal Geophysical Research Letters:
Gray areas are the norm, based on a decade of satellite observations that cover every acre (actually every square kilometer) on the planet. Dots that are gold, orange or deep red show areas with a decrease in greenness. Scientists call this the Normalized Difference Vegetation Index (NDVI on this chart) or the greenness index.