A new report from the Global Commission on the Economy of Water (GCEW) reveals that humans have, for the first time in history, disrupted the balance of the global water cycle. The global water cycle consists of two major components: “blue water” which is the liquid water in lakes, rivers, and aquifers, and “green water” which is the water stored in soil and plants. Historically, people often focused only on the significance of blue water in the water cycle while neglecting the role of green water. Green water returns to the atmosphere via plant transpiration and plays a crucial role in the formation of rain and snow, with nearly half of the land rainfall originating from green water supply.
The stability of the water cycle is vital for maintaining climate change and supporting carbon sink vegetation. Forests and wetlands, as carbon sink vegetation, can absorb and store large amounts of carbon dioxide, thus helping to mitigate global warming. However, current wetland destruction and deforestation are diminishing the capacity of these natural carbon sinks, leading to more greenhouse gases remaining in the atmosphere and exacerbating the trend of global warming.
As global warming intensifies, high temperatures become more frequent and extreme. This not only accelerates water evaporation but also increases the frequency of droughts. In drought conditions, vegetation is more fragile and prone to fire. Consequently, high temperatures and droughts jointly raise the risk of fire outbreaks, which not only destroys vegetation but also further reduces the carbon sink ability, creating a vicious cycle.
The report indicates that nearly 3 billion people and over half of the world’s food are in arid regions or areas with unstable total water resources. The water crisis may endanger more than half of the world’s food production.
Regarding how to maintain a normal water balance, it’s a crucial question. We need to explore and implement various measures. This could include better water resource management, such as improving irrigation efficiency in agriculture to reduce water waste, promoting water conservation in daily life and industry. Additionally, protecting and restoring wetlands and forests can enhance the capacity of natural carbon sinks and help regulate the water cycle. We should also focus on developing sustainable water technologies and policies to ensure the long-term stability of the water cycle and support global food security and climate stability. What are your thoughts? Welcome to leave a message.