Human activity has disrupted the global water cycle “for the first time in human history,” leading to an escalating water crisis that threatens economies, food production, and lives, according to a groundbreaking report released this week.
The report from the Global Commission on the Economics of Water, comprising international leaders and experts, highlights how decades of harmful land use and poor water management have intersected with the climate crisis, placing “unprecedented stress” on the water cycle.
The water cycle is the intricate system through which water circulates on Earth. Water evaporates from various sources, including lakes, rivers, and vegetation, ascending into the atmosphere to form expansive rivers of water vapour that can travel great distances. Eventually, this vapour cools, condenses, and returns to the surface as rain or snow.
Current disruptions to the water cycle are inflicting real hardships. Nearly 3 billion individuals are experiencing water scarcity, crops are withering, and urban areas are sinking as groundwater levels are depleted.
Without immediate intervention, the repercussions will escalate considerably. The report warns that the water crisis could jeopardize over 50% of global food production and reduce national GDPs by an average of 8% by 2050, with losses potentially reaching 15% in low-income countries.
“For the first time in human history, we are pushing the global water cycle out of balance,” stated Johan Rockström, co-chair of the Global Commission on the Economics of Water and a contributing author of the report. “We can no longer depend on precipitation, the source of all freshwater.”
The report distinguishes between “blue water,” which refers to the liquid water found in lakes, rivers, and aquifers, and “green water,” the moisture held in soils and vegetation.
Although green water has often been neglected, the report emphasizes its equal significance in the water cycle, as it evaporates from plants, contributing to approximately half of all rainfall over land.
The report also highlights that disruptions to the water cycle are closely linked to climate change.
A consistent supply of green water is essential for sustaining vegetation that sequesters carbon responsible for global warming. However, human activities, such as wetland destruction and deforestation, are compromising these vital carbon sinks and exacerbating climate change. Consequently, the heat driven by climate change is drying out landscapes, diminishing moisture levels, and increasing the risk of wildfires.
This water crisis is intensified by the growing demand for water. The report estimates that individuals need at least 4,000 liters (over 1,000 gallons) per day to maintain a “dignified life,” significantly exceeding the 50 to 100 liters deemed necessary for basic needs by the United Nations. Furthermore, this demand surpasses the water supply that many regions can offer from local sources.
Richard Allan, a climate science professor at Reading University in England, stated that the report “depicts a dire situation regarding human-induced disruptions to the global water cycle, which is our most vital natural resource that ultimately supports our livelihoods.”
He noted that human activities “are changing the fabric of our land and the air above, leading to a warming climate that exacerbates both wet and dry extremes while disrupting wind and rainfall patterns.” Allan, who did not participate in the report, emphasized that the crisis can only be tackled through improved management of natural resources and significant reductions in greenhouse gas emissions, told CNN.
The authors of the report assert that global governments must acknowledge the water cycle as a “common good” and work together to address it. Nations are interconnected not just through lakes and rivers that cross borders but also through atmospheric water, which can travel vast distances. This implies that decisions made in one country can adversely affect rainfall patterns in another.
The report calls for a “fundamental regearing of where water sits in economies,” including better pricing to discourage wastefulness and the tendency to plant water-thirsty crops and facilities, such as data centers, in water-stressed regions.
“The global water crisis is a tragedy but is also an opportunity to transform the economics of water,” said Ngozi Okonjo-Iweala, director general of the World Trade Organization and a co-chair of the commission that published the report. Valuing water properly is essential, she added, “so as to recognize its scarcity and the many benefits it delivers.”
