Senior Writer at Formative Content.
In just 250 seconds you can watch 20 years of seasons flash by – polar ice caps shrink and grow again, while in more temperate climates the land darkens as plants grow, only to become paler as winter approaches.
The animation, created for NASA, is not a cartoon of how the changing seasons might look if sped up; it is an amalgamated collection of images harvested from satellites over the past two decades, from September 1997 to September 2017.
Click the image below for the full visualization.
As well as being nice to look at, the visualization has much to say about how climate change is affecting our planet.
And scientists say the 20 years of sped-up data can be used to measure how plant life is growing and changing, which in turn shows how successfully it is at using carbon in the atmosphere.
The animation also shows the abundance of life on land and at sea.
In the oceans, dark blue to violet shades represent warmer areas where there is little life due to lack of nutrients. Greens and reds, meanwhile, depict cooler, nutrient-rich areas.
These include coastal regions where cold water rises from the sea floor, bringing nutrients with it, and areas at the mouths of rivers that carry nutrients from the land into the sea.
On land, green represents areas of abundant plant life, such as forests and grasslands, while tan and white depict areas where plant life is sparse or non-existent, such as the deserts in Africa and the Middle East, as well as snow and ice at the poles.
Over time, its possible to observe spring arriving earlier and autumn lasting longer in the Northern Hemisphere, and the Arctic ice caps receding. There is less ice in the Antarctic too, he adds, but this is not as obvious.
Meet El Niño and La Niña
Werdell was particularly struck by a “hugely productive bloom of biology” that exploded in the Pacific along the equator from 1997 to 1998.
This “bloom” was the visible sign of a big climate fluctuation – described as El Niño and La Niña – that took place when warm currents from the central-eastern equatorial Pacific mixed with cooler-than-normal water in the equatorial Pacific. A line of bright green shows the result: an algae bloom.
For scientists and policymakers, understanding such occurrences as El Niño and La Niña is important so they can prepare better for them: for example, algae can contaminate commercial seafood stocks, damaging local economies.
Algae is also harmful to sea life. One study found it caused sea lions to suffer brain damage and memory loss, leading to some being stranded on beaches or straying far from their usual hunting grounds.
But there are other lessons to be learnt from pictures of Earth taken from space.
Let there be less light?
The amount of night-time light pollution on Earth is increasing – and we know this to be true because of pictures taken of our planet from space by a NASA satellite earlier this year.
While scientists had expected to see more light pollution in expanding emerging economies, they had thought less-polluting LEDs and better use of technology to turn off unused lights might have meant decreased levels in developed countries, but this was not the case.
Animal life can be severely disrupted by too much light pollution, leading to smaller populations and disruption to delicate ecosystems. In humans, it can disturb sleep patterns that contribute to poor health and lower productivity levels.
Policy lessons from space
Light pollution has other economic and environmental knock-on effects: it is a waste of energy and someone, individual or state, is paying for it. It is also likely to mean carbon resources are being wasted to produce it, which adds to the production of harmful carbon dioxide and increases global temperatures.
And it is also damaging in less measurable ways: for instance, the more light pollution there is, the less able we are to see the stars and planets,.
We can see what has been happening to our planet for a long period of time thanks to satellite images. If we are to preserve Earth’s biodiversity and natural wonders, it is essential that we heed the wisdom such images from space can offer.