This video was made in collaboration with the national center for science. Education. The central valley of california is one of the united states, bread baskets or more accurately, produce baskets for folks who live there common sense, water conservation is second nature linda.
An agricultural laborer has lived here all her life and she carefully teaches her children to be conscious of their water usage. They use shorter showers and are careful with their tooth brushing routines.
They know to give their unfinished drinking water to the houseplants and the family yard. Outside reflects an awareness of california's increasingly dry climate, it's, an appealing rock garden lined with cacti and succulents.
Yet the surrounding tomato and almond farms where linda has worked for the last 15 years are thirsty industries during the last. Several decades, as california has experienced an extended drought, the central valley has been forced to rely on groundwater steadily, drawing down the level of the water in the underlying aquifer.
The drawdown has been so extreme in fact that the land above the aquifer is noticeably sinking. Climate change is expected to make fresh water scarcity worse, both in the water stressed central valley and around the world, because when greenhouse gases accumulate and the atmosphere warms, the water cycle changes with the rise of global temperatures comes the accelerated melting of sea ice and glaciers, Which returns water, that's, been locked up for thousands of years back into the dynamic water cycle.
Warmer temperatures lead both to greater evaporation of that newly introduced water and an atmosphere that can hold more of that water as vapor, because water vapor is a potent greenhouse gas, increased evaporation leads to increased warming and increased warming leads to increased evaporation and so on.
A phenomenon known as a positive feedback loop and ultimately, as evaporation, increases so too does water scarcity. On the other hand, increased amounts of atmospheric water, vapor and heat energy can also combine to fuel events like hurricanes.
It may seem counter-intuitive, but big storms can actually intensify water's scarcity when too much water arrives all at once. Much of it will simply run off leaving aquifers unreplenished. On top of that, a big hurricane can also cause extensive infrastructure damage and contamination that further worsens water scarcity.
These global scale phenomena have local consequences in california's. Central valley residents like linda, have seen firsthand how sustained drought has pitted individuals against industry. In the struggle for a finite and critical resource water, the central valley grows the bulk of california's, produce and accounts for an estimated 12 percent of overall agricultural product in the u.
s. When the industry began to develop california's, climate was much wetter through years of drought. However, the central valley has sustained its agriculture by drawing heavily on its aquifers and reservoirs, but this diminishing water reserve is increasingly contaminated with agricultural byproducts, like nitrate and arsenic, which concentrate into a potent concoction as the water level drops.
Linda is well aware that her well, water is undrinkable. Even showering in the water gives her youngest daughter, sarah a rash, and she currently relies on donations of potable water from a local non-profit, but that water never seems to be enough, which is one of the reasons she teaches her children to be so careful with water And linda and her family are not alone.
California's. Current governor estimates that one million californians have unsafe drinking water, but this is just the beginning. Scientists expect climate change to exacerbate california's, droughts, along with its fire seasons, which means it's, likely that the state's.
Water woes will only get worse, but california isn't alone in experiencing water scarcity. The amazon rainforest has experienced unprecedented droughts in the last few years, and the fires that roared through the system in 2019 are indicative of that dryness.
The amazon is important for many reasons: biodiversity, carbon storage and culture, but the sheer volume of the forest and its component trees means that it drives its own weather system about half of the rainwater that falls in the amazon is generated from transpiration from trees themselves.
Recent research has shown that large, mature trees withstand dry conditions better than the short agricultural vegetation that often replaces it following deforestation. However, when exposed to sustained drought, even big trees die because trees play such an important role in the local water cycle.
Their loss is expected to fundamentally transform the amazon ecosystem with jungle, eventually transforming into savannah and the more trees lost the worse the drought, which in turn stresses and kills more trees.
It's, another positive feedback loop and unfortunately, there is also a third loop when the bodies of the dead trees are decomposed stored, carbon is released back into the atmosphere, strengthening the greenhouse effect and further driving climate change.
This problem, isn't limited to the central valley and amazon rainforest. However, approximately 70 of the world's. Population faces water scarcity at least one month a year, with 500 million people about 6 percent of the population exposed to severe water scarcity all year round.
Most often, this scarcity is exacerbated by poor distribution management and political practices. More so than an overall global shortage of fresh water humans have become large consumers of water, as our population has boomed over the last several decades, but consumption is not equitable.
The agricultural industry is responsible for consuming almost 70 percent of the world's, fresh water with large corporations that enjoy political and economic clout consuming heavily, as in the case of the produce companies who employ linda in the california central valley there linda and Her community suffer the consequences of environmental and water mismanagement, while agricultural industry continues to drain local aquifers, but there are alternatives to our current practices.
Water, efficient solutions, such as improved irrigation cover, cropping and agroforestry, can help reduce agriculture's drain on fresh water. In addition to protect the limited amount of fresh water we do have access to, we must regulate water pollution and improve wastewater treatment.
All the while employing water recycling techniques with proper, filtration and purification to conserve as much water as possible, addressing freshwater scarcity globally. Much like addressing climate change, however, requires a multi-faceted approach, and because the two issues are intricately connected, addressing freshwater scarcity will require a concerted effort to mitigate climate change with just two degrees celsius of warming.
It's, estimated that 40 of the population might be exposed to extreme water scarcity. Climate change solutions then like combining strategies to sequester carbon with those to reduce emissions or water scarcity solutions.
These strategies, though, must require systemic socioeconomic change. To address the increasing demand for fresh water, they must tackle the problem at its source, with policies to protect the rights of the people from industrial overuse.
Water scarcity is a recurring reality for the majority of the world's. Population and as climate change alters the water cycle and exacerbates extreme weather, it's, likely that more people will suffer without transformative action.
The water saving techniques that linda uses today will become the new normal for more and more people worldwide for linda and especially for her daughter. Sarah water shortages and contaminated water are all they know.
Yet there are ways forward addressing climate change and alleviating water scarcity will require immense political action, as will assuring that their consequences, don't fall disproportionately on those who are most vulnerable, but for such a vital resource as water.
The effort will be well worth it. Hey everyone, charlie here, if you & # 39, ve, been watching our changing climate for a while or just stumbled across this video, and are wondering how you can help me make more videos then consider supporting the show on patreon.
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com our changing climate and become an occ patron, the script for This video was written by annie a graduate student research fellow at the national center for science education. She did an amazing job.
It was a lot of fun to work with her. So thank you to annie and thank you all for watching. I'll, see you next time.