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A Blueprint for Disaster: Humans Have Pushed Earth’s Freshwater Cycle to Breaking Point

March 10, 2024

A Blueprint for Disaster: Humans Have Pushed Earth’s Freshwater Cycle to Breaking Point

Freshwater Hands

Human activities have pushed the Earth’s freshwater cycle beyond its natural state, with significant alterations observed since the mid-twentieth century due to pressures like damming, irrigation, and climate change. This underscores the critical need for immediate action to safeguard vital freshwater resources.

New research indicates that the worldwide freshwater cycle has undergone significant changes, moving well away from the conditions observed prior to industrialization.

A recent study examining global freshwater resources reveals that human actions have significantly altered the planet’s freshwater cycle, causing variations that far exceed the conditions prior to industrialization. The study shows that the updated planetary boundary for freshwater change was surpassed by the mid-twentieth century. In other words, for the past century, humans have been pushing the Earth’s freshwater system far beyond the stable conditions that prevailed before industrialization.

This is the first time that global water cycle change has been assessed over such a long timescale with an appropriate reference baseline. The findings, published in Nature Water, show that human pressures, such as dam construction, large-scale irrigation and global warming, have altered freshwater resources to such an extent that their capacity to regulate vital ecological and climatic processes is at risk.

Analyzing Human Impact

The international research team calculated monthly streamflow and soil moisture at a spatial resolution of roughly 50×50 kilometers using data from hydrological models that combine all major human impacts on the freshwater cycle. As a baseline, they determined the conditions during the pre-industrial period (1661-1860). They then compared the industrial period (1861-2005) against this baseline.

Their analysis revealed an increase in the frequency of exceptionally dry or wet conditions –deviations in streamflow and soil moisture. Dry and wet deviations have consistently occurred over substantially larger areas since the early 20th century than during the pre-industrial period. Overall, the global land area experiencing deviations has nearly doubled compared with pre-industrial conditions.

…click on the above link to read the rest…

The Great Flood

March 31, 2018

The Great Flood

There is little doubt that the amount of water on earth really does not change. There is simply what is known as the Water Cycle whereby evaporation moves water to the sky and then it is redistributed as rain elsewhere. Therefore, the likelihood of an actual flood in Biblical terms that covered the entire world is unlikely. What we do know is that there is a wealth of evidence that the movement of the plates clearly resulted in the great flood that created the Mediterranean sea and there is also evidence that there are cities under the Black Sea no less the Mediterranean.

There is evidence that there was a tremendous flood when there was a break in the land at the Straits of Gibralter. What has surfaced is evidence that when that breach took place, the water rushed into the basin at probably around 100 mph. This is certainly something that would be remembered and probably handed down from generation to generation. (see Scientific American)

Nevertheless, it is also obvious that the sea level has risen in the Mediterranean even since the time of Julius Caesar (100-44BC).  The city of ancient Alexandria in Egypt lies below the sea. Obviously, even in relatively modern times, the sea level has risen flooding communities. So actually stating definitively when did the Biblical Event of the flood take place is difficult to pinpoint because there have been great floods from 3 million years ago to 2,000 years ago.  What is certain is that the sea levels have risen and fallen and this is part of nature – not instigated by humans.

Sandra Postel: Repairing The Water Cycle

February 8, 2016

Sandra Postel: Repairing The Water Cycle

It’s now a top priority for our species 

Water, water, every where,
And all the boards did shrink;
Water, water, every where,
Nor any drop to drink.
The very deep did rot – Oh Christ!
That ever this should be.
~ Samuel Taylor Coleridge

El Niño has been dropping much-needed rain this winter on a parched American West. But it’s making little difference to the greater water scarcity issues the US as well as the rest of the world is increasingly facing.

Here to talk about the state of the world situation for fresh water — arguably the single most important resource to humans on the planet, next to oxygen — is Sandra Postel, Director of the Global Water Policy Project, author, lecturer, and former National Geographic Fellow. The punch-line to her message: as more and more demands are placed on our finite freshwater supply by human consumption and climate change, intelligent conservation is now an absolute must:

Competition for water that arises when you have increasing scarcity — competition between cities and farms within the same area, competition between states and provinces within the same country, and then of course, competition and tensions between countries that share rivers. And so these are fundamental concerns going forward: we still have rising population and we pursue economic growth — all this places rising water demand against a finite supply. And so just navigating that tricky course in the years ahead is a tremendous challenge.

Our water future is being determined by population, consumption and technology. As well as the failure of policy to move us toward a more water efficient set of practices.

Take agriculture: the fact that we are growing with water in California, water in the Colorado River basin where water is fairly precious, we are growing some very low-value crops and using a lot of water to do that and often doing it inefficiently.

…click on the above link to read the rest of the article…

Climate Change Poses Existential Water Risks

February 22, 2015

Climate Change Poses Existential Water Risks

We often hear it said that climate change is too abstract to win the support needed to effectively combat it.

But the primary way we will experience climate change is through the water cycle – through droughts, floods, depleted rivers, shrinking reservoirs, dried-out soils, melting glaciers, loss of snowpack and overall shortages of water to grow our food and supply our cities.

If that’s not tangible enough to take action, I don’t know what is.

We’re already seeing this new world of water unfold before our eyes. And while I must add the obligatory caveat that scientists cannot prove that human-induced climate change is the causeof any single event we have witnessed (with the likely exception of the 2013-14 Australian heat waves), scientists do know – and warn – that these are the kinds of events to anticipate more of as climate change unfolds.

 

Last week, a new study by researchers with the National Aeronautics and Space Administration and Cornell and Columbia Universities warned that the U.S. Southwest and Great Plains are almost certainly in for unprecedented “mega-droughts” during this century.

Using 17 different state-of-the-art climate models, the scientists found “a coherent and robust drying response to warming.” The findings were published in the journal Science Advances.

Under scenarios of both moderate and high greenhouse gas emissions, the team concludes that these regions can expect drought periods even more severe than the driest centuries of the last millennium. It was after one of those long droughts that the Hohokam, an advanced, irrigation-based civilization that thrived for a thousand years in what is now the Phoenix area, disappeared.

 

…click on the above link to read the rest of the article…

 

Olduvai IV: Courage
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Olduvai II: Exodus
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