Water Diplomacy Talks -- Governance Of Atmospheric Water

Washington DC, United States

During the thousands of years that humans have utilised freshwater in surface water bodies and groundwater aquifers, laws and customary practices have developed for its utilization and protection.

Renee Martin-Nagle examines governance of our planet’s atmospheric water.

Martin-Nagle is President and CEO of A Ripple Effect plc. She is also Treasurer of the International Water Resources Association and a Visiting Scholar at the Environmental Law Institute. In June 2019 she received a Ph.D. in Law from the University of Strathclyde in Glasgow, Scotland; a book based on her thesis, “Governance of Offshore Freshwater Resources”, will be published by Brill Publishers in early 2020.

As impacts of climate change, continuous population growth water-intensive consumption patterns create imbalances in freshwater availability, unconventional sources of freshwater, including atmospheric water, will become more appealing. At the same time, geo-engineering proposals such as solar radiation management that are designed to mitigate climate change also have potential for large-scale impacts on the hydrological cycle. Diversion of atmospheric water through weather modification (WM) or geo-engineering (GE) can lead to artificially enhanced rainfall in one area to the detriment of “downstream” neighbors. Currently there is only one global treaty that addresses WM – the 1978 Convention on the Prohibition of Military and Other Hostile Use of Environmental Modification Techniques, which has 78 parties and addresses weather modification exercised as a means of warfare. The 1944 Convention on International Civil Aviation grants each state “complete and exclusive sovereignty over the air space above its territory”, which includes the territorial sea. However, that convention has been interpreted to apply only to over-flights. While some nations have domestic laws about WM, thus far no applicable global governance regime has been formally proposed. In order to avoid potential conflicts, a set of legal principles must be developed to govern WM and GE.

Capturing atmospheric water

Current mechanisms for removing freshwater include fog harvesting, mechanized capture of water vapor and cloud-seeding, and other techniques for controlling atmospheric water may be perfected in the future.

Fog harvesting can be accomplished very simply with land-based screens or mesh that condense and capture the water droplets. Land-based mechanised systems for capturing water vapor can provide as much as 5000 liters of freshwater daily. Cloud-seeding involves dispersing substances into the air that allow ice crystals to condense around the ice nuclei, with the crystals then falling as precipitation. Atmospheric rivers carry 90% of the north-south water vapor transported from the tropics in streams that can be hundreds of miles wide and over a thousand miles long. While they deliver critical precipitation, atmospheric rivers can also cause floods, mudslides and landslides; techniques for controlling atmospheric rivers have not yet been developed.

GE takes several forms, including greenhouse gas removal and solar radiation management such as albedo enhancement, space reflectors and stratospheric aerosols. All of the GE proposals would affect distribution and intensity of atmospheric water and precipitation, but the effects would vary according to the type of geo-engineering employed. At the highest level of the atmosphere, the US government through its HAARP program has experimented with sending high-energy transmissions into the ionosphere in order to alter the temperature in one of the highest layers of the atmosphere. While neither geo-engineering nor HAARP focuses on control or capture of freshwater, these methods would modify weather patterns and thus precipitation.

Governance of weather modification

In the absence of guidance from international law on governance of WM, policymakers desiring to manage its implementation and prevent catastrophic changes may begin with some well-defined water law principles. Harvesting fog or rain that would have naturally passed into another state could be viewed as a new version of the discredited rule of capture; eventually collaborative arrangements similar to unitization agreements may replace the rule of capture in the skies as they have on land. In another analogy to international water law, the tension between upstream and downstream riparians could arise for atmospheric flows, and the principle of equitable and reasonable utilisation may take the form of benefit-sharing, with states agreeing to share the benefits and risks of altered precipitation patterns. However, given the potential for catastrophic consequences, the principle of no significant harm must be considered, and the precautionary principle should be the guiding light for governance of weather modification. The polluter pays principle could easily be adapted to include damage done by artificially-induced floods, mudslides, landslides and other types of unnatural disasters.

Other principles such as data-sharing, cooperation and advance notice should be mandatory, although advance notice may be unnecessary if cooperation through joint commissions is embraced, practiced and enforced. Last but certainly not least, environmental protection must be addressed, and environmental impact assessments should accompany any proposal for all but the slightest weather modification, in spite of the uncertainty that may accompany any predictions.

All of the substantive and procedural principles discussed above would apply to any type of weather modification that could have transboundary impacts. Decisions regarding stakeholder involvement and limitations on sovereignty with respect to WM may be more complex and contentious.

Fog-harvesting and mechanized capture of water vapor will both have only local effects, so any joint commissions addressing those types of WM could rely on stakeholder representatives from the locally affected environs; any limitations on sovereign could be agreed by the parties. However, cloud-seeding and manipulation of atmospheric rivers could have both local and regional impacts, and states should be more inclusive in selecting the representatives to serve on any joint commission. Where WM has the potential for regional impacts, states should agree to greater limitations on their sovereignty, ceding control of major decisions to the joint commission. Geo-engineering and ionospheric disruption are designed to have widely dispersed, global effects, and therefore a joint commission for these types of weather modification should feature broadly inclusive, consensus-based representation and should be based on best available science and technology. States will also need to determine the extent of liability for damage caused by weather modification, and whether strict liability, limited liability or immunity should attach to state action.


Given the enormous stakes involved and the rapid advance in technology, governance of atmospheric water should be urgently addressed by an interdisciplinary group of policy and science experts with a mandate to develop a proposed set of guidelines that would serve as a starting point for discussions. This suggestion raises an obvious question – who or what should host this group?