Water Scarcity and Artificial Rainfall: The Positive and The Negative Effects of Cloud Seeding, including Health Hazards and Climate Implications.

Globally, over 2 billion people lack access to safe drinking water due to scarcity, including sanitation and hygiene services.

Climate change is one of the factors exacerbating the issue of lack of equitable access to safe drinking water and sanitation, particularly in rural and remote areas, leading to increased health complications for older people, individuals with disabilities, and children. 

According to Samantha Stratton-Short, —UNOPS Head of Strategic Initiatives, “Climate change, conflicts, and water pollution are widening the gap to ensuring clean water and sanitation for all, especially for women and marginalized groups.”

Artificial Rainfall is a scientific weather modification technique, in which silver iodide is used to generate or enhance more rainfall to augment sufficient water supplies in arid regions and combat droughts. However, it is still a scientific process engulfed with a complex web of risks and health uncertainties.

There are many safety concerns, especially on flooding, ecosystems, and biodiversity. These concerns were focused on human health and its implications for our changing climate, as part of its potential downside.

Cloud seeding involves infusing clouds with silver iodide particles to stimulate condensation and precipitation. While it has been used for decades, recent interest has resurfaced due to worsening water shortages and climate-related disruptions.

What is Silver Iodine?

Silver iodide is a chemical compound composed of silver and iodine that has been used in the production of agricultural pesticides, antiseptics in medicine, cloud seeding, and as a yellowish-white powder used in photography, as a pigment. It's also used in manufacturing certain types of glass and is sometimes found in some air pollution control devices. The AgI is slightly soluble in water and is more toxic than silver.

Silver iodide (AgI) is considered the most common nucleating material used in cloud seeding. Many studies concluded that AgI are too low to induce a toxicological effect because they only remain in soils and sediments for some time, but emphasized cumulative environmental effects from continuous practice.

Health Hazards

As early as 1965, the National Science Foundation called for research into the human consequences of weather modification. Unfortunately, these concerns remain under-explored.

The silver iodide used in cloud seeding raises questions about its impact on human health and is linked to numerous health risks such as toxicity, reproductive disorders, developmental defects, and cancer. When oxidized, may also lead to Iodism, a type of poisoning caused by iodine, causing skin rashes, headaches, and respiratory issues. Prolonged exposure to silver iodide can cause argyria, a condition that causes the human tissues to turn blue or gray when too much of it is deposited in the body.

The silver ion is also known to inhibit glutathione peroxidase and Sodium-Potassium ions- ATPase activity, disrupting and reducing chemical reactions, oxidation, and intracellular ion concentrations. These nanoparticles are believed to disrupt the mitochondrial respiratory chain, causing oxidative stress, reduced ATP synthesis, and DNA damage. 

Environmental Hazards

Cloud seeding introduces potentially harmful chemicals (AgI) into the atmosphere. While proponents claim little evidence of harm, the long-term effects remain uncertain. These chemicals, once exposed to the environment, the particles spread and pollute the atmosphere.

There is also a growing concern about carbon dioxide masking, underlying the sensitivity of our climate to rising carbon dioxide levels. For instance, If pre-industrial cloud cover was higher than previously thought, the masking effect may have been overestimated, affecting climate projections.

THE CLIMATE IMPLICATIONS

1. Cloud Cover and Cooling: Historically, scientists assumed that pre-industrial skies were sunnier, but recent experiments challenge this notion. The clouds play a vital role in regulating solar energy. Increased cloud cover reflects sunlight back into space, contributing to an overall cooling effect.

2. Rain Enhancement Research Programs: The Advancement of rain enhancement science projects such as nanotechnology and cloud seeding are projects embarked on to maximize water vapor condensation and rainfall, aiming to secure water supplies and mitigate the effects of climate change.

For example, in 2016, the UAE Presidential Court launched a global research initiative, and the UAE Research Program for Rain Enhancement Science (UAEREP), under the administration of the National Center of Meteorology (NCM), to address the critical issue of water security in the field of rain enhancement.

The UAEREP funded millions of dollars for research projects, ongoing training programs, and capacity building involving worldwide scientists and scientific institutions, contributing to global efforts in water resource management, climate adaptation, and sustainable development. The UAE has been involved in cloud-seeding operations since the late 1990s.

In November 2023, a four-year pilot joint project was also launched in the US with an aim to increase precipitation from 5% to 15% by the Santa Ana Watershed Project Authority (SAWPA), from five water districts by the Eastern Municipal Water District, Inland Empire Utilities Agency, Orange County Water District, San Bernardino Valley Municipal Water District and Western Municipal Water District.

The SAWPA is the state-approved Regional Water Management group that brings together the watershed community and serves as a Joint Powers Authority for addressing regional water issues, to reduce imported, more expensive, and less reliable sources of drinking water in the region. The project was aimed at increasing local water production by up to 40 percent and supporting its member agencies for long-term restoration of their degraded environment.

Conclusion

Cloud seeding offers hope for water-scarce regions, but remains a double-edged sword that requires rigorous research, transparency, and consideration of associated health risks.

It's essential to weigh in the benefits and the risks, to ensure that our silver bullets do not inadvertently harm the very communities we aim to develop. As they say, every cloud has its shadow; therefore, it will be wise to make sure the one we have above us is not a toxic one.

References:

1. https://thebulletin.org/2022/08/dodging-silver-bullets-how-cloud-seeding-could-go-wrong/
2. https://connectusfund.org/12-important-pros-and-cons-of-cloud-seeding
3. https://www.scientificamerican.com/article/cloud-seeding-surprise-could-improve-climate-predictions/
4. https://www.technologyreview.com/2022/03/28/1048275/scientists-advance-cloud-seeding-capabilities-with-nanotechnology/
5. https://psl.noaa.gov/outreach/education/science/clouds_and_climate.html
6. https://www.popsci.com/environment/cloud-seeding-drought-climate-change/
7. https://en.m.wikipedia.org/wiki/The_UAE_Research_Program_for_Rain_Enhancement_Science
8. https://www.uaerep.ae/mobile
9. https://www.sbvmwd.com/about-us/santa-ana-watershed-project-authority
10. https://www.unops.org/news-and-stories/news/developing-inclusive-water-sanitation-and-hygiene-infrastructure
11. https://abc7.com/amp/southern-california-water-cloud-seeding-riverside-county-inland-empire/14341706/
12. https://pubmed.ncbi.nlm.nih.gov/27517140/
13. https://www.icliniq.com/articles/first-aid-and-emergencies/silver-iodide-toxicity
14. https://www.toxno.com.au/toxins/substance_id_7822.html