I attended a fascinating lecture today on carbon mineralization for carbon dioxide removal. The speaker, an enthusiastic researcher who admitted to not having outgrown the “graduate student habit” of showing too many slides, delivered a compelling presentation that challenged many of my assumptions about climate change mitigation.
An Eye-Opening Perspective on Global Energy
The lecture began with a striking fact: the average world per capita energy consumption is about 2,500 watts. When was the last time Americans consumed at that level? Surprisingly, around 1776 at the founding of our nation.
As the speaker pointed out, this fundamentally changes how we should think about energy consumption. Those below this energy threshold—living without electric lights or refrigeration—don’t want to remain there. And those of us above it certainly don’t want to return to those conditions. Despite idealistic notions about conservation, global energy reduction simply isn’t a realistic option.
The speaker reminded us that approximately 750 million people (9% of the global population) still lack access to electricity, and about 3 billion people lack clean cooking fuel. These statistics brought home the human dimension of our energy challenges.
The Uncomfortable Truth About Fossil Fuels
I was particularly struck by the speaker’s candid assessment of global fossil fuel use. They highlighted India’s straightforward position: eradicating poverty comes first. With 20% of their population lacking electricity access in 2014, their priorities were clear. The speaker even quoted Prime Minister Modi’s recent celebration of India reaching 1 billion tons of coal production in 2024.
Despite India’s impressive renewable energy investments, 77% of their electrical generation in 2023 still came from coal—up from 70% in 1985. This wasn’t presented as a criticism but as a reality we must acknowledge.
Even more eye-opening was learning about my own backyard: in the New York City area, 89% of electricity was generated by fossil fuels in 2021, with only 9% coming from zero-emission sources. The retirement of the Indian Point nuclear plant has actually made our local energy mix more carbon-intensive, not less.
The speaker shared projections that by mid-century, about 45% of global electrical generation will still come from fossil fuels. More than half of all coal and gas-fired power plants worldwide have been installed since 2000, with 40-50 year expected lifetimes. Unless we’re prepared to buy out those utilities, they’ll continue operating for decades.
Climate Activism vs. Pragmatic Solutions
One of the most thought-provoking moments came when the speaker contrasted Bill McKibben’s framing of the fossil fuel industry as “public enemy number one to the survival of our planetary civilization” with the complex reality of global energy needs. The question hung in the air: Are we average energy consumers in New York friends or enemies in this framing? What about the government of India?
The speaker quoted Barack Obama’s more nuanced approach: “We have to try to train issues in ways that at least consider the possibility of a win-win situation rather than a zero-sum situation.” This resonated with me as a more productive path forward.
The Scale of the Challenge
Using slides from UN reports, the speaker outlined our mitigation challenge: we need to avoid about 50 billion tons of emissions by 2055 (roughly equivalent to current annual emissions). Perhaps 30-40% of those mitigations can come from adding renewables and electrifying vehicles, but that leaves 10-20 billion tons requiring carbon capture and storage.
Even more daunting, we need to remove greenhouse gases from the air—about 10 billion tons per year by 2055, and 20 billion tons per year by 2100. The sheer scale of this undertaking became apparent.
Making Economic Sense of Climate Action
I found the economic analysis particularly illuminating. The speaker walked us through the evolution of the “social cost of carbon” estimates—from the Obama administration’s $42 per ton to the Trump administration’s drastic reduction to $1-7 per ton (by only considering damages to the United States), to the Biden administration’s increase to $190 per ton.
The speaker used a compelling analogy about “fat tail distributions” of climate risk—if there’s even a small probability of catastrophic outcomes affecting billions of people, the true cost could be much higher than our standard estimates suggest.
According to Goldman Sachs research the speaker cited, we can abate the first 25 billion tons of emissions with technologies costing less than $50 per ton, but mitigating from 36-50 billion tons would exceed $100 per ton, with the hardest-to-abate sectors potentially costing more than $250 per ton.
At $100 per ton, mitigating all current emissions would cost about $5 trillion annually—approximately 5% of current global GDP. This would drop to 2.5% by mid-century and 1% by century’s end as economies grow.
Historical Perspective: London’s Sewage Revolution
The most memorable analogy came when the speaker described London in 1858, when the city retrofitted the world’s largest metropolis with a central sewage system after years of cholera outbreaks. They spent about 2% of GDP for a decade on this infrastructure, and today, modern societies routinely spend 1-2% of GDP on waste management.
The implication was clear: when society finally agrees that putting greenhouse gases in the atmosphere is equivalent to throwing waste into the streets, we’ll have the economic framework to address it. Until then, we need to keep developing better technologies and cheaper options.
Carbon Mineralization: Turning CO₂ to Stone
The speaker finally turned to their area of expertise: carbon mineralization. The process involves taking CO₂ dissolved in water or air and interacting it with magnesium or calcium-bearing silicate minerals to form solid carbonate minerals that are non-toxic, permanent, and stable.
Seeing the images of white carbonate veins formed in colorful rocks that originated in the Earth’s upper mantle helped visualize this promising approach. The elegant simplicity of turning our carbon problem literally into stone left me with a sense of cautious optimism.
I came away from the lecture with a more nuanced understanding of our climate challenges. The speaker demonstrated that we need both urgent action and pragmatic realism—acknowledging global energy needs while developing technologies that can help us achieve our climate goals.
These are my notes from a lecture at Lamont-Doherty Earth Observatory on carbon mineralization for carbon dioxide removal.
