2023-11-04 07:00:00
Title: Human Activities Threaten Earth’s Ecosystems as Air, Soil, and Freshwater Become Saltier
Subtitle: Rising Demand for Salt Raises Environmental Concerns
Date: 04.11.2023 – 06:00 a.m.
Author: Tiago Robles
Source: Meteored Brazil
In a recent study published in the journal Nature Reviews Earth & Environment, researchers have highlighted the alarming impact of human activities on the Earth’s air, soil, and freshwater, leading to increased salinity. The study warns that these rising salt levels could pose a significant threat to life on the planet in the future.
The global production of various types of salt has skyrocketed in the last century, with approximately 300 megatons of sodium chloride (NaCl), commonly known as table salt, being produced annually. Professor Sujay Kaushal, a geology expert at the University of Maryland, explains that the growing demand for salt comes at a high cost to both the environment and human health.
The researchers have focused on understanding how human activities influence the salt cycle. They analyzed data on salt ions in subsoil and surface waters and estimated that overaccumulation of mineral salts, known as soil salinization, has impacted around 1 billion hectares of soil worldwide, an area equivalent to the size of the United States.
The “anthropogenic salt cycle” refers to the accelerated transport of salts to the Earth’s surface through mining, raw material extraction, increased salt fluxes into the atmosphere through saline dust, and elevated soil salinization and evaporite formation due to desiccation. This cycle has been significantly altered by anthropogenic activities such as mining, land development, agriculture, water treatment, road construction, and other industrial processes. In extreme cases, these activities have rendered drinking water unfit for consumption.
While common perceptions of salt often revolve around sodium chloride, the researchers emphasize that other types of salts associated with limestone, gypsum, and calcium sulfate also disrupt ecosystems. According to Kaushal, this highlights the need to broaden our understanding of the diverse impacts human-induced salts can have on the environment.
The study also reveals that the concentration of salt ions in streams and rivers has increased over the past five decades, in parallel with the global rise in salt usage and production. Additionally, the air itself has become saltier in certain regions, as drying lakes release clouds of salty dust into the atmosphere.
This salt dust poses further risks by accelerating snowmelt, potentially causing harm to communities reliant on snow for their water supply, particularly in the western United States. Salt ions can combine with pollutants in soils and sediments, creating harmful “chemical cocktails” that circulate in the environment.
Given these concerns, the researchers urge the establishment of limits for the safe and sustainable use of salt on our planet, similar to measures taken to reduce carbon dioxide (CO₂) emissions. The excess salt not only threatens fresh water reserves but also impacts food and energy production, air quality, human health, and infrastructure.
Kaushal acknowledges the complexity of the issue, stating that salt is not currently considered a major contaminant in drinking water in the United States. However, he believes that harmful levels of salt in the environment necessitate regulatory actions.
As human activities continue to impact the Earth’s delicate ecosystems, addressing the issue of salt-induced salinization is crucial to ensuring a sustainable future for our environment and the well-being of all species that depend on it.]
#Humans #disrupting #salt #cycle #global #scale