The natural world has undergone an almost unimaginable regime change, reflecting the vast and growing dominance of humanity on our planet’s most important resource: freshwater.
Researchers say this is the first global survey of human effects on the water cycle. Scientists have used NASA’s satellite measurements to remotely measure the water level in a staggering number of reservoirs: the world’s lakes, ponds and 227,386, large or small.
Human-operated reservoirs, such as artificial dams, contain only 9.9 percent of this massive planet-scale system of surface water storage, masking a membership about how much humanity really controls small fractional freshwater fluctuations.
When calculating the amount of overall change in water levels in both natural and man-managed systems, it turns out that man-controlled reservoirs represent 57 percent of all surface water variability – more than half flowing and flowing in saltwater systems.
Stanford University geographer Sarah Cooley explains, “We think of the water cycle as a fairly natural system: rain and snow flow into rivers, which run into the ocean where the whole evaporation cycle resumes,” explains Sarah Cooley, a geologist at Stanford University. .
“But humans are actually significantly interfering in that cycle. Our work shows that humans are responsible for the variability of most of the seasonal surface water storage on Earth.”
The results, obtained from 22 months of data collected by NASA’s Ice, Cloud and Land Elevation Satellite 2 (ICESAT-2), provide a snapshot of the world’s first type of water storage, small enough to capture and measure water storage. As a football field in the survey.
“Previous satellites have come nowhere near it,” says Cooley, but while scientific achievements are commendable, there are no takeaways.
“There are a lot of ways in which this is bad for the environment.”
Water scarcity ranges from the negative impact on natural ecosystems to the dangers of greenhouse gas emissions from artificial reservoirs.
Of course, man-operated reservoirs also have other positive consequences: in addition to controlling water supply, they enable things like hydropower systems, while dams can also protect against flooding.
Even so, owning one is still beyond the reach of the average person.
The second is quite reminiscent of how much our species affects the environment around us – with the result impossibly large, we can only hope to see them from space.
“All the changes in the body of freshwater around the planet – all the floods, droughts and blizzards that push the lake level up and down – humans have ordered about 60 percent of that variability,” says Lure Rance Smith, an environmental scientist at Brown University. Says Lure Rance Smith.
“It’s a tremendous influence on the water cycle. In terms of human influence on the planet, it’s the same with the effects on land cover and atmospheric chemistry.”
These findings are reported Nature.
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