As the impacts of climate change become more severe, some scientists and policymakers have begun asking a provocative question: if we cannot reduce greenhouse gas emissions fast enough, should we try to engineer our way out of the problem? Geoengineering, the deliberate large-scale intervention in the Earth's climate system, is one of the most ambitious and controversial ideas in modern science. And it raises questions that go far beyond engineering.
Geoengineering encompasses a range of technologies designed to counteract the effects of climate change by directly manipulating the Earth's climate. These approaches generally fall into two categories.
The first is solar radiation management (SRM), which aims to reduce the amount of sunlight reaching the Earth's surface. Proposals include injecting reflective aerosol particles into the stratosphere, brightening marine clouds, or even deploying space-based sunshields. These approaches do not address the underlying cause of climate change (excess greenhouse gases) but could, in theory, buy time by reducing global temperatures.
The second category is carbon dioxide removal (CDR), which focuses on pulling greenhouse gases out of the atmosphere and storing them. Approaches range from planting vast numbers of trees and enhancing the carbon absorption capacity of soils, to direct air capture facilities that chemically extract CO2 from the atmosphere, to ocean fertilization schemes that stimulate the growth of carbon-absorbing plankton.
Films from the Future (Chapter 12) uses The Day After Tomorrow as the entry point for discussing geoengineering and climate science. The 2004 disaster film depicts a catastrophic collapse of the Atlantic thermohaline circulation, a massive ocean current system that helps regulate global climate, triggering a sudden new ice age. The science is wildly exaggerated for dramatic effect, but the underlying concern, that human activity could push Earth's climate system past tipping points with devastating consequences, is grounded in real science.
The book acknowledges that The Day After Tomorrow barely mentions geoengineering directly. But the film's depiction of a climate catastrophe that outstrips our ability to respond raises the question of whether deliberate climate intervention might be necessary as a last resort. The chapter explores this possibility while emphasizing the enormous risks involved.
Geoengineering the climate means intervening in a system of staggering complexity. Earth's climate involves interactions between the atmosphere, oceans, ice sheets, land surfaces, and living organisms, all operating on different timescales and influencing each other in ways that are not fully understood. Intervening in such a system with the intention of producing a specific outcome is an act of extraordinary ambition, and the potential for unintended consequences is immense.
Research into geoengineering has expanded significantly in recent years, driven by growing concern that emissions reductions alone may not happen fast enough to prevent dangerous levels of warming. Small-scale experiments in solar radiation management have been proposed or conducted. Direct air capture technology is being commercialized, though at costs that remain far above what would be needed for deployment at a meaningful scale.
The governance challenges are perhaps even more daunting than the technical ones. If one nation decides to deploy solar radiation management unilaterally, the effects would be felt globally, and they would not be evenly distributed. Some regions might benefit while others suffer. There is currently no international framework for governing geoengineering, and the geopolitical implications of one country or coalition deciding to alter the global climate are profound.
Geoengineering matters because it sits at the intersection of desperation and hubris. The case for studying it is strong: if climate change outpaces our ability to reduce emissions, having geoengineering options available could reduce suffering. But the risks of deploying these technologies prematurely or poorly are enormous, and the governance frameworks needed to make responsible decisions are largely absent.
The book frames geoengineering as a powerful illustration of a theme that runs throughout Films from the Future: the gap between our ability to develop powerful technologies and our ability to use them wisely. Climate change is a problem of our own making, created by the unintended consequences of technologies that seemed entirely beneficial at the time. Geoengineering runs the risk of repeating this pattern at an even larger scale.