Scientists have suggested that a necessary and rapid reduction in climate warming might be best achieved through the reflection of sunlight from clouds and particles in the atmosphere. Hence, removing carbon is a critical accelerant to achieving a sustainable climate. Could such an intervention (or ‘geoengineering’) work in the struggle against climate change?
According to Kelly Wanser, Executive Director of SilverLining, observations of effects from volcanic releases and pollution indicate that increasing the atmosphere’s reflectivity by just 1-2 percent could offset up to 2°C of global warming.
Wanser says that we need to look at such solutions if we are to tackle the risk posed by climate change. According to Wanser: “Disasters that were far-off possibilities in the past are realities for people everywhere. The most vulnerable are being hit hardest– by drought, famine, floods, and unescapable, deadly heat. Going forward, we face an increasingly dangerous environment in which Earth’s temperature will continue to rise in every scenario for emissions reduction, through the mid-century, displacing up to 3.2 billion people.”
In terms of alternative solutions, Wanser explains: “There are escalating private and public investments in approaches for removing greenhouse gas from the atmosphere. If enough is removed, the climate will cool relatively quickly. But in general, these approaches will take decades to scale to the levels required. We may get lucky, but otherwise, our best current failsafe lies in increasing the reflection of sunlight from the atmosphere.”
This is where approaches that involve increasing the reflection of sunlight by dispersing a sea-salt mist from ships into clouds over the ocean (“marine cloud brightening”) or releasing particles into the upper atmosphere (“stratospheric aerosol intervention”) come in.
Developing working solutions will be complex and capital-intensive to study and scale and they would need to be supported by significant effort and money.
There are other challenges too, says Wanser: “The underlying science problem – the effects of particles (“aerosols”) on clouds and climate – is one of the largest areas of uncertainty in climate research. Observations and model representations of these processes are far weaker than they need to be, for both predicting climate and for evaluating interventions.”
However, Wanser is also optimistic for change: “With the right advances, we might develop ways to prevent the escalation of impacts like wildfires, droughts and storms and early warning and response systems for major abrupt changes, similar to the U.S. program in place today to prevent asteroid strikes.”
As an example, SilverLining is advancing aspects of the solution, including advances in observation and models to better predict near-term climate generally. This includes collaboration with Amazon Sustainability Data Initiative and the U.S. National Center for Atmospheric Research.
