Solar Geoengineering

In a recent paper on the WIREs website, a group of scientists have weighed in on their concerns about one technology being considered as a potential solution for global warming.

  

Let's start with this definition:

 

"Albedo is defined as the proportion of light that is reflected from a surface and is measured on a scale of zero to one with zero albedo surfaces generally being darker in colour and high albedo surfaces generally being lighter in colour.  As such, dark-colours surfaces tend to absorb more light."

  

In the case of the world as a whole, roughly 30 percent of the sun's energy is reflected back into space.  Dark coloured surfaces with low albedo like asphalt and roofing shingles absorb more of the sun's energy, resulting in these surfaces heating up.  In contrast, white surfaces with high albedo like snow cover reflect most of the sun's energy back into the atmosphere and, as a result, do not heat up as much.

  

Solar geoengineering technology proposes to use various methods to reflect sunlight back into space, thereby cooling the earth.  There two of the main technologies that are being considered include:

 

1.) Stratospherical aerosol injection or SAI - this technology is similar to what happens during an eruption of volcanic dust.  SAI technology would inject and aerosol containing small particles which end up in the stratosphere and reflect sunlight thereby cooling the earth's surface.

 

2.) Marine cloud brightening or MCB - this technology would involve the use of marine vessels to spray sea salt into low level clouds located in marine areas to enhance the brightness and reflectivity of the clouds which would result in greater sunlight reflection.

  

Here is a diagram showing how these two methods could be used to increase planetary albedo, thereby reducing earth's temperature:  

 

In 2021, Harvard's Solar Geogineering Research Program under its Stratospheric Controlled Perturbation Experiment or SCoPEX was planning to launch a balloon into space from the Swedish Space Corporation infrastructure located near Kiruna, Sweden and inject a small amount of aerosol consisting of calcium carbonate (less that 1 kilogram) at an altitude of 20 kilometres in the stratosphere.  The propelled balloon will then be flown back through the plume to measure the temporal evolution of the perturbation resulting from the plume and study how the aerosol in the plume is developing.  Thanks to significant public backlash, the Bill Gates-backed project was shelved and will take place in 2022 if it takes place at all.

  

Let's close this section with this video:

 

 

With all of this background, let's now look at the recently published document entitled "Solar geoengineering: The case for an international non-use agreement".  Here is a list of the scientists involved and their affiliations:

 

 

Let's look at some key excerpts with my bolds:

 

"Solar geoengineering is mainly discussed as an intervention at planetary scale to lower global mean temperatures in response to global warming. The most prominent proposal is the injection of aerosols in the stratosphere to inhibit the influx of solar energy. Interventions that are more regional or local in intent, such as marine cloud brightening to protect fragile ecosystems such as the Great Barrier Reef, are also conceivable, but they differ significantly in terms of governance, politics, and scale...."

 

"The idea of solar geoengineering is gaining traction in a few industrialized countries. In March 2021, for instance, a report by a committee of the US National Academy of Sciences concluded that the United States should establish, ideally in international collaboration, a research program to assess the feasibility of solar geoengineering as a stopgap measure for addressing anthropogenic climate change. Individual researchers in the United States have called for a globally organized “mission-driven research program” on solar geoengineering  and for a special IPCC report on this topic....

 

Advocates of solar geoengineering research argue, implicitly or explicitly, that international climate governance has been largely ineffective and that the Paris Agreement's goal of limiting global warming to well below 2°C and preferably to 1.5°C is unlikely to be met, given current trends and policies (e.g., Svoboda et al., 2018; Wagner, 2021). Therefore, proponents argue, solar geoengineering should be researched now to better understand its potential efficacy and to have it available, if deemed feasible, as a future option...

 

To us, these proliferating calls for solar geoengineering research and development are cause for alarm, as they risk the normalization of these technologies as a future policy option. So far, the risks and efficacy of solar geoengineering are poorly understood..."

 

The authors' main concern is the lack of a global governance mechanism to oversee the technical, political and ethical risks of these massive solar geoengineering interventions given that such interventions would require complex decisions that would have to be made on a global scale.  They believe that the potential benefits and risks of such a program would be unevenly spread, particularly negatively impacting people of the global south who are living in the poorest nations on earth where a change in climate could have a dramatic negative impact on their lives.

 

Here is another excerpt:

 

"...any global decisions on the details of the deployment of solar geoengineering are unlikely to find consensus. Disagreements about some parameters—for example, the degree of cooling, the duration of deployment, or the specific latitudes and distribution of aerosols—will inevitably occur. Such situations would require clear and reliable decision-making procedures for solving these disagreements....In short, the deployment of solar geoengineering at planetary scale would require entirely new international organizations with convincing means of democratic control and unprecedented enforcement powers. Such organizations do not exist."

 

For many reasons, not all of which are covered in this posting, the authors of the paper are calling for a "Non-use Agreement on Solar Engineering" which would included the following five core prohibitions and measures:

 

1.) The commitment to prohibit their national funding agencies from supporting the development of technologies for solar geoengineering, domestically and through international institutions.

2.) The commitment to ban outdoor experiments of solar geoengineering technologies in areas under their jurisdiction.

3.) The commitment to not grant patent rights for technologies for solar geoengineering, including supporting technologies such as for the retrofitting of airplanes for aerosol injections.

4.) The commitment to not deploy technologies for solar geoengineering if developed by third parties.

5.) The commitment to object to future institutionalization of planetary solar geoengineering as a policy option in relevant international institutions, including in assessments by the Intergovernmental Panel on Climate Change.

  

This group of scientists are not the only scientists that are concerned about solar geoengineering.  The Union of Concerned Scientists has also expressed its concern about the use of solar geoengineering as quoted here:

 

"To date, research to scope the risks and potential of solar geoengineering has mostly been conducted through computer-based modelling and natural observations.

 

Proposals and plans to expand research in solar geoengineering now include initiatives to conduct small-scale atmospheric experiments in the US and in Australia’s Great Barrier Reef. Even small-scale experiments with limited environmental and societal risk deserve significant public scrutiny and debate as they accelerate attention and legitimate concern about the potential for larger-scale, potentially riskier experiments, and possible deployment.

 

Because solar geoengineering has global implications, its consideration as a climate response requires effective international governance. Sound governance would need to be sustained for a very long time. Even uses intended to be “temporary,” such as deploying stratospheric aerosols to limit peak warming while we aggressively reduce emissions, would likely need to be sustained for a half-century or more."

 

The Union also notes that scientists currently have some idea regarding the impact of volcanic eruptions on the global atmosphere but that level of knowledge is insufficient to understand a sustained program of geoengineering.

 

Let's close with this press release dated March 25, 2021 from the United States National Academies of Sciences, Engineering and Medicine:

 

Here's a quote from the press release: 

  

"The report says the U.S. Global Change Research Program (USGCRP) should lead the effort to establish and coordinate a solar geoengineering research program across federal agencies and scientific disciplines, with funding in the range of $100 million-$200 million over the first five years. USGCRP would enable oversight and governance of research activities, including ensuring peer review, coordinating budget proposals and requests, periodically assessing progress, and defining program goals. Funding should be set aside specifically for implementation of governance and public engagement efforts.

 

The research agenda should encompass 13 specific areas of research, which can be grouped into the following three broad areas of investigation:

 

1.) Context and goals for solar geoengineering research, including research on the goals and social context for solar geoengineering research, developing modeling scenarios, strategies for decision-making under uncertainty, and the capacity needed for all countries to engage meaningfully on this issue.

2.)Impacts and technical dimensions, including the properties of injected reflective particles and their interactions with clouds and atmospheric processes, possible climate outcomes and subsequent impacts on ecological and societal systems, technical requirements for advancing these technologies, and advancing monitoring and attribution capabilities.

3.) Social dimensions, including research on public perceptions of and engagement with solar geoengineering; domestic and international conflict and cooperation; effective governance of solar geoengineering; and integration of justice, ethics, and equity considerations."

As you can see, some scientists are very concerned about the prospect of the use of solar geoengineering technology to mitigate climate change and its potential long-term negative impact on the entire world.  Since the science is still in its infancy, their concern is valid.

 

Let's close with this thought on solar geoengineering:

 

What could possibly go wrong?