Startup Make Sunsets promises to disrupt… the stratosphere?

Humanity has managed to stabilize its carbon emissions, but they have not yet begun to decline. It seems increasingly likely that we will emit enough to commit to at least 1.5°C warming, and we must act quickly to avoid exceeding 2°C. This inability to get our emissions in order may force us to consider alternatives such as extracting carbon dioxide from the air or geoengineering to reduce the amount of sunlight received.

Of the two, geoengineering comes with the longer list of unknowns, with a recent report from the National Academies of Sciences saying, “Scientific understanding of many aspects of solar geoengineering technologies remains limited, including how they might affect extreme weather, agriculture , natural resources, ecosystems. , or human health”.

So some Silicon Valley guys naturally decided to go ahead and start a startup that would offer geoengineering for a fee. The company claims to offer heating offsets despite considerable geoengineering unknowns. And it’s even worse than it sounds; based on an MIT Technology Review article, the company has already started launching balloons into the stratosphere, although it is unable to determine if they are actually deploying their payload.

Designing the stratosphere?

Geoengineering is generally defined as manipulating the environment in order to alter the climate. Given that definition, our widespread burning of fossil fuels is a form of geoengineering. But in the face of our climate’s steady warming, most references to geoengineering now focus on ways to combat that warming. While several possible techniques have been considered, the most practical approach appears to be shooting reflective particles into the stratosphere to reduce the amount of sunlight Earth receives.

The general concept has already been validated by volcanoes, which can release sulfur dioxide into the stratosphere and cause cooling in the years following an eruption. For example, the biggest eruption of the last century (Mount Pinatubo) cooled the planet for about three years before the sulfur dioxide it pumped into the stratosphere fell and exited the atmosphere below in the form of rain.

Sulfur dioxide is cheap and we have the technology to transport it into the stratosphere without the need for an eruption, and it could be an attractive alternative to the many costly downstream impacts of climate change. The “may” comes in large part from the many unknowns involved in your quest. Everything from plants to solar panels depends on sunlight reaching Earth. And while we know the approach works, we still don’t know enough detail to assign a specific cooling value to a given amount of sulfur dioxide. This sulfur dioxide also forms sulfuric acid when exposed to water, which can have environmental impacts if applied at levels necessary to change the climate. Finally, relying on geoengineering commits us to pursuing it for as long as it takes to reduce atmospheric carbon to manageable levels.

For all these reasons, the scientific community has been very hesitant about the idea. The National Academies report mentioned above suggests that there are so many unknowns that any research we undertake on the subject must be designed in a way that does not facilitate advancement and continuity. “Deliberate outdoor experiments involving the release of substances into the atmosphere should only be considered when they can provide critical observations that cannot be provided by laboratory studies, modeling, or experiments of opportunity such as volcanic eruptions,” the report authors concluded. “Outdoor experiences must be subject to appropriate governance, including permits and impact assessments.”

Leave a Comment