We call earth the blue planet with reason — water covers 71% of our world’s surface, a fact that sets the third rock from the sun apart. But humans are land creatures, and we have lived and thrived on earth because of the vegetation our planet supports. We depend on the green.
Now recent footage gathered by a National Oceanic and Atmospheric Administration (NOAA) satellite shows in detail just how that green changes over the course of the seasons — and how we’re altering it with man-made activity. The video above is distilled from footage collected from April 2012 to April 2013 by the NASA/NOAA Suomi NPP satellite. The satellite can detect pixel-by-pixel changes in the earth’s vegetation over the course of a week or several decades. The areas of darkest green show dense vegetative growth — think rain forests — while lighter areas represent land with less plant cover, like deserts and mountains. Oceans and fresh water in the video are left white.
In North America, the video shows how greenery changes over the course of the year, as fall turns to winter and vegetation shrinks thanks to snowfall and dropping temperatures. Wildfires — like the deadly fires blasting through Arizona now — torch forests but over the long term can help promote revitalized plant growth. In South America, the video shows how deep green land surrounding the wide Amazon River has changed thanks to deforestation. The land has been scarred as forests have been cut down or burned to make room for agriculture and settlements. In China, the most populous country on the planet, unprecedented urban sprawl has left pockets of white amid the dense green along the coasts. Shanghai — a city with a metro population of over 23 million people — is seen as a blank white spot.
The detail NOAA’s satellite imagery can offer is especially valuable in the Horn of Africa, where minute changes of vegetative growth can offer advance warning for oncoming droughts. At the same time, a sudden flourishing of green could signal an uptick in malaria — a disease that kills more than 3,000 African children a day — as the Anopheles mosquito that hosts the malaria parasite thrives on dense, wet vegetation.
The Suomi NPP satellite allows us to see how our planet is changing in near real time. And given how fast we’re changing it — thanks to man-made greenhouse gases and sprawling development — it’s an eye in the sky we need more than ever.