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! Most people know about many dangers of the #ClimateEmergency, particularly those related to temperature changes and sea level rise, but many people don't realize the full risks involved with rainfall and #foodsecurity. This 
will be a quick primer.
! Most people know about many dangers of the #ClimateEmergency, particularly those related to temperature changes and sea level rise, but many people don't realize the full risks involved with rainfall and #foodsecurity. This will be a quick primer.
A major overlooked facet when it comes to the #ClimateCrisis is that of changes in rainfall patterns. At first this seems obvious; after all, rainfall is largely dependent on temperature. But many of the ripple effects of even slight changes in rainfall are difficult to see.
Precipitation change is also difficult to discuss because it is so geospatially varied. Precipitation is subject to a range of incredibly complex factors, making it difficult to predict. This map shows the percentage change in precipitation over the last ~100 years.
But let's focus on something more tangible to grasp. I want you to think of the area you grew up in (wherever on earth that may be). Think about the seasonal cycles of the flora, the fauna, and the people. Think about how much was planned on rain arriving at the correct time.
You may have been aware of certain things, like when thunderstorm season was, or when the garden needed watered, but it goes so much deeper than that. Precipitation has huge consequences for flood management, hydroelectric power, drought, and most importantly: agriculture.
No matter how technologically advanced we may become, we are still tied to natural limitations by agriculture. For thousands of years, as conditions gradually changed in certain areas, humans moved to more fertile lands. Drought, particularly, has brought down empires.
When rainfall conditions change too quickly, humans, reliant as we are on agriculture, struggle to cope. Even in ancient cultures with superior irrigation technologies (the Egyptian New Kingdom, Western Roman Empire, Khmer Empire), when the rains move, the people fall apart.
The United States, in particular, is far too arrogant when it comes to the assumption that our water resources are steady or reliable. We are arrogant to assume that we will invent new ways to circumvent scarcity. We are rapidly approaching the literal bottom of the well.
One important thing to understand about looming water crisis is this; not all water is renewable. Let me explain what I mean by this. "Renewability" as a concept is entirely dependent on rates.
Wood is a "renewable" resource, sure, but only if more wood mass is added to all trees on earth at a rate equivalent to the wood mass that dies off. Even though this is a possible rate to achieve, we are losing forest every day because humans are accelerating the rate of loss.
Not all water resources are equally renewable. "Water stress" is a measure of how much more water is being extracted than is being returned to a water supply. It's a measure of relative rates.
This image is familiar to many people. However, this idealized version of the water cycle assumes that all aspects are in balance. Human intervention has dramatically reduced rates of infiltration while dramatically increasing rates of runoff and transpiration from plants.
Let's focus on a more tangible example. In the United States, the Great Plains are often referred to as "the breadbasket" of the US. Songs are sung about "amber waves of grain" extending to the horizon. When plants grow, they take water from the soil and release it into the air.
The United States great plains region is not a region that receives a lot of precipitation. (For reference the average yearly precip for the continental United States as a whole is 30/inches/year.) It is a dry region, with not enough moisture to support forests.
So our question becomes; where did all the water come from? How does the environment on the left become the neat green circles on the right?
The "breadbasket of the United States" is irrigated with prehistoric water. Specifically, water that seeped into the earth in this region 2 to 6 million years ago, when the area was wetter. The midwest is living on borrowed rain. And it is running out.
In the 1930s, the United States government made a massive push to farm this region, hoping to provide food security, jobs, and greater political control. The tall grasses that had grown there for millennia were cut, and crops were planted instead.
The seasonal crops that were substituted had extremely shallow root systems compared to the prairie grasses that had evolved to suit this environment. The deep roots meant they could access water deep in the soil, while agricultural plants could only access it on the surface.
From 1930-1931, this bullheaded expansion of European-style agriculture and crops to a dry prairie environment went so poorly that it is estimated a full 50% of crops in Arkansas failed. A series of dry years, combined with a lack of roots to hold soil together, created disaster.
This was the Dust Bowl. It was a devastating lesson in what can go wrong when environmental conditions, especially water limits, are ignored. Many people know the Dust Bowl was an environmental catastrophe, but few people know that it was one that was never solved; only delayed.
To "solve" the Dust Bowl crisis, the United States government put massive resources into drilling wells and promoting irrigation technologies. The Great Plains are underlain by an ancient aquifer, where water has been stored for millions of years. So the United States mined it.
The Ogallala Aquifer is immense, the result of water accumulating in one region for four million years. It underlies states from South Dakota to Texas, and it is the major source of water that fuels Great Plains agriculture and turned a dry prairie into amber waves of grain.
It's difficult to know how much time is left to continue to drain the Ogallala Aquifer. Some small areas could sustain our current extraction for hundreds of years further, while huge regions of the Ogallala have already run dry.
So what happens when the Ogallala runs out? The Dust Bowl returns. You may recognize the portrayal of this very real threat from Interstellar. But even in Interstellar, the "solution" is to find more resources, not to work within the limits of the environment.
Perhaps the most frightening thing about this real-life parable of greed and overconsumption is that it is far from the only example. In this map, blue areas show where irrigation exceeds rainfall. This means regions where stored, nonrenewable water is being used for agriculture.
In fact, regions, where water stress is high (meaning more water is being used than rainfall exists to replenish water supplies), are regions more likely to be subject to intensive irrigation. In particular, regions with fertile soil but low rainfall are intensively farmed.
The question of when our method of industrial agriculture becomes unsustainable is a fallacy; it always has been. The "green revolution", just as the industrial revolution was, is simply using new, unrenewable sources of production. The more unsustainable infrastructure built...
...the further we have to fall. Here is a photo of the famous Lake Mead, behind the Hoover Dam, which supplies a huge amount of the water needs and hydroelectric power to the city of Las Vegas. Its water level just hit a record for the lowest it has been since it was built.
The reason is the same as in Ogallala; we are utilizing water that runs off of glaciers (water storage) faster than it can replenish itself. The Hoover Dam was praised as a miracle of modern times, a symbol of the rising United States' monument-building abilities.
The American West is renowned as the region of wilderness conquered, of manifest destiny, of the mythical revisionist histories of miners and cowboys and farmers and foresters and explorers and conquests and colonialization. It's the land of dreams, of hopes, of disillusionment.
If anything, the American West and its "taming" is symbolic of the American Empire at its heart. It is larger than life, it is deeply invested in the narrative of humans bending natural phenomena to their will, and it is living on borrowed time.
Some may think the American Empire was built on oil, or on the atom, or on gold. Make no mistake; the American Empire was built on water, extracted, used, shipped, contaminated and sent downstream. This bounty will run out. Will we, as a society, learn to live within limits?
With the introduction of the industrialized global economy, the big picture of water usage, as with the big picture of climate change as a whole, is not a factor of individual decisions, but corporate ones. Usage for drinking supplies is a fractional percentage of total use.
Yet, in the United States, public water supplies are still considered the least important water usage. When droughts strike regions, public water is curtailed. Even in regions without drought, water sources are often contaminated and unsafe to drink.
When it comes to matters of water scarcity and safety, as when it comes to all issues associated with climate change -- individual actions matter far less than collective actions.
Rather than interrogating others about their shower length, interrogate government officials who issue water contracts. Encourage investment into local water safety systems. Encourage agricultural practices and crops suited to the environment you live in.
Hold corporate entities accountable for the waste they generate and the resources they use. We are running out of borrowed water, and we are running out of borrowed time.
When the well runs dry, who will go thirsty?
When the well runs dry, who will go thirsty?
If you are in the United States, this is a good resource for creating meaningful change to limit water privatization. https://www.corporateaccountability.org/water/
It is also important to note that many people in the United States, particularly those in Appalachia and living on reservations, do not have access to public water, and are at heightened risk for environmental contamination, consequences from droughts, and food insecurity.
This is a brief overview to a few issues involved in water scarcity and climate change, with a major focus on the Western United States. The issues present are far deeper and more complex than the simple overview here. I will do my best to answer questions on this thread.
If you would like to support more of my science communications, social justice organizing, or writings on history, environment, trans issues, disability issues and water, please consider supporting me on Patreon. This is my current main income source, so thank you!
Here is the link! https://www.patreon.com/AlexPetrovnia
