|Many of the water systems that keep ecosystems thriving and feed a growing human population have become stressed over many years. / Photo by: nd3000 via 123rf|
Our planet has 70 percent of its entire surface covered by water, which is why it is easy to think that the element will always be plentiful. However, only 3 percent of the world’s water is freshwater—the water we use for drinking, taking a bath, and irrigating our farmlands. Moreover, two-thirds of this is tucked away in frozen glaciers or otherwise unavailable for our use. Thus, it is not surprising that more than two billion people across the world lack access to potable water.
BBC, a British free-to-air television news channel, reported that global water demand is projected to increase by 55 percent between 2000 and 2050. Agriculture accounts for 70 percent of global freshwater use. Aside from that, most of it is being used to raise livestock and for farming aquatic organisms such as fish and plants. Unfortunately, many of the world’s freshwater sources are being drained faster than they are being replenished due to two main factors: population growth and climate change. Worse, reports showed that 12 out of 37 of the world’s major aquifers are receding. Every year, the Ganges Basin in India is depleting by an estimated 6.31 centimeters due to population and irrigation demands. Jay Famiglietti, the senior water scientist at NASA, warned that “the water table is dropping all over the world. There’s not an infinite supply of water.” This means that every drop of water is increasingly becoming more precious.
Aside from the fact that freshwater is running out, many of the water systems that keep ecosystems thriving and feed a growing human population have become stressed over many years. It has been known that lakes, rivers, and aquifers are drying up or becoming too polluted to use. At the same time, the climate crisis has been altering patterns of weather and water across the world. As a result, there have been water shortages and droughts in many countries.
The World’s Plants are Becoming Water-Wise
The world’s freshwater is under severe pressure and the plants are doing their part in fighting climate change while surviving. A 2017 study published in Nature Communications reported that land-based vegetation has boosted its carbon dioxide absorption from the atmosphere by 17 percent compared to 30 years ago. According to The Conversation, a not-for-profit media outlet that uses content sourced from academics and researchers, this is due to today’s higher-CO₂ conditions. As a result, plants are soaking up more carbon dioxide by using less water.
“We found that rising CO₂ levels are causing the world’s plants to become more water-wise, almost everywhere, whether in dry places or wet ones,” the authors said. This means that climate change is causing the world’s plants to grow in a more water-efficient way—a rare piece of good news when talking about the impacts of global environmental change.
The world’s plants becoming water-wise benefits us in several ways, including boosting water availability for the well-being of society and the natural world, improving food production, and strengthening plants’ vital role as global carbon sinks. Plants have learned to open up pores called stomata in their leaves to increase their carbon dioxide intake while allowing water to sneak out. At the same time, they learned how to minimize water loss in the process while taking up carbon to build new leaves, stems, and roots.
The study showed that this sophisticated adaptation is common in boreal and tropical forests. They are known for being good at increasing ecosystem water use efficiency and uptake of carbon dioxide.
Plants Will Demand More Water
The overall result of the study is that carbon uptake increases while water consumption does not. However, there’s also bad news about it. Researchers from Dartmouth College discovered that this is only limited to the tropics and the extremely high latitudes. Those plants on the mid-latitudes will not make the land wetter but drier, which has massive impacts on millions of people across the world.
Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, reported that the researchers used a novel method, which was developed earlier by lead author Justin S. Mankin and colleagues to calculate the future runoff loss to vegetation in a warmer, carbon dioxide-enriched climate. They used it to examine how freshwater availability may be affected by changes in the way precipitation is divided among plants, rivers, and soils.
Mankin explained that vegetation plays an integral role in determining what water is left on land for people since over 60 percent of the global water flux from the land to the atmosphere goes through plants. "The question we're asking here is, how do the combined effects of carbon dioxide and warming change the size of that straw?” he said.
|Plants learned how to minimize water loss in the process while taking up carbon to build new leaves, stems, and roots. / Photo by: Oxana Medvedeva via 123rf|
The study discovered that plants of the future will consume more water than in the present day. As a result, there will be less water available for people living in North America and Eurasia. This is because more vegetation will consume more water for a longer amount of time as photosynthesis becomes amplified. Plants are more likely to grow since carbon dioxide concentrations are increasing. Thus, they will leave less water in soils and streams.
“Our research shows that we can't expect plants to be a universal panacea for future water availability. So, being able to assess clearly where and why we should anticipate water availability changes to occur in the future is crucial to ensuring that we can be prepared,” Mankin said.
The world heavily relies on freshwater to survive. We must conserve water as much as possible because there’s a high possibility that we would run out of water supply soon.