Reading David Keith’s “A Case for Climate Engineering” After 10 Years Through CDR Lens

Reading David Keith’s “A Case for Climate Engineering” After 10 Years Through CDR Lens

A few weeks ago, while browsing the "Environment" section at the East Village bookshop Strand, I found a small, red book titled "A Case for Climate Engineering". It was slightly worn and priced at $7.50, so I didn't hesitate to add it to my growing stack of books.


Climate engineering, often associated with solar radiation modification (SRM), is a potential stratospheric intervention to decrease the amount of solar radiation the Earth absorbs. The book by Keith explains the technical procedure, which involves dispersing tiny sulfur acid droplets approximately 60,000 feet into the sky to reflect sunlight. This concept draws inspiration from nature, such as the 1991 eruption of the Piantubo volcano, which released similar aerosols into the atmosphere. This formed a "blanket" that reflected sunlight, immediately lowering the average ground temperature.

Climate engineering was a hot topic when Prof. Keith, an Applied Physics professor at Harvard, wrote this book to address concerns and controversies related to this field. The prominence of this discussion just ten years ago was the first thing that struck me. Climate technologies, particularly physical interventions for carbon removal, have made significant strides in the last 5-10 years. They've developed a range of methodologies and systems, set new records in carbon removal, and made substantial progress in the field. They've even become trusted solutions endorsed by conservative organizations like the Department of Energy (DoE). However, climate engineering has not enjoyed the same acceptance, despite Keith's persuasive argument in his book. It's intriguing to understand why this is the case, and I’ll touch on just a few points.


“Our climate choices would be easy if we were facing an imminent existential threat” (pp. 24)

These words were penned in 2014, before numerous world-altering events took place, including COVID-19, Trump's presidency, wars in Ukraine and Israel, Taiwan's chip crisis, and others. Keith advocates for a moderate and responsible approach to climate engineering research, arguing against its marginalization or delegitimization. He suggests that we are not yet in an existential crisis that warrants extreme measures.

Reflecting on humanity's handling of COVID, it's questionable whether we're capable of identifying an existential threat or effectively marshalling the necessary resources and personnel to address it. Despite significant advancements in healthcare and other sectors during this time, did it truly challenge our system? That's unclear.

In the book, the year 2030 is referred to frequently, often preceded by the word "by". In 2024, "by 2030" doesn't seem far off. The severity of the threat has increased, and we've already crossed many potential tipping points. Are we not already in a full-fledged emergency?

Socio-economic changes vs. technological solutions

As an avid reader on the socio-economic theory of climate change, I found Prof. Keith's balanced and mature perspective particularly enlightening. Two points stood out to me.

First, Keith acknowledges, and reiterates, that capitalism is a significant factor contributing to climate change. He doesn’t condemn capitalism, but emphasizes that it has led to excessive consumption, rapid growth, exploitation, growing disparities, and overall imbalance. He advocates for reducing carbon emissions at their source, but also underscores the inconvenient truth that this will require time, money, and effort, without compromising our well-being. I compare that to what I hear and read today in the CDR field, and wonder how the economic context got lost so fast to the point that you hardly hear any mention of it.

Keith characterizes the leftist approach since the 1960s as society-based, advocating for local thinking, knowing the farmer, prioritizing indigenous communities in preservation and restoration projects, and taking personal responsibility for consumption. He suggests an alternative: relying more on technology, science, and engineering, rather than depending solely on people's ability to change their behavior. Keith notes, "Air pollution was reduced by catalytic converters, not carpooling," among other examples. Reading this section of Chapter 5: Ethics and Politics, I was reminded of the growing divide I perceive between "sustainability" and "climate" as professional strategies.

Moral hazard and risk compensation

In 2014, a significant opposition movement existed against climate engineering, and judging by the state of affairs in 2024, it seems this opposition prevailed. Various concerns were raised about the environmental safety of this method, extending beyond its large-scale implementation to also include research and experimentation aspects.

Another point of resistance centered around the potentially negative impact that endorsing climate engineering could have on efforts to reduce emissions. Some people were worried that we might become so enamored with these solutions that we forget to address the root cause of the problem, a situation they dramatically referred to as a "moral hazard." Keith countered this argument with the concept of "risk compensation," which is the extent to which preventive or protective solutions influence our willingness to take risks. He argued that it is logical to revisit carbon reduction goals as climate engineering becomes increasingly proven and reliable.

Discussing the ethics of climate engineering and its correlation to the reliance on Carbon Dioxide Removal (CDR) in achieving net-zero, I believe we've experienced two major shifts as a climate-conscious society. Firstly, we've become less rigid and more open to experimenting, blending, and even failing, provided our ultimate goal is deep decarbonization. This is positive progress in my view.

On the flip side, our discourse on climate ethics has lost some of its vibrancy. I attribute this to the political polarization of the past decade, which has fostered an authoritarian right wing with a strong preference for fossil fuels, viewing them as symbols of freedom. Simultaneously, an authoritarian "green left" has emerged, embodied by figures like Greta Thunberg. This polarization risks oversimplifying the climate conversation, which I find concerning.

To conclude, reading this short book felt like a trip down the modern, somewhat forgotten, history of climate technologies, and I think we can learn more than a lesson from it as we’re building CDR solutions, decarbonization strategies or climate policies.