Capturing Carbon in the Wild — Why Storing Carbon in Open Environmental Systems Needs a Stronger Scientific Framework

A growing consensus suggests that keeping climate change within globally acceptable bounds is likely to require "negative emissions," the climate community's term for actively removing CO2 from the atmosphere. In particular, approaches that use natural environmental systems to draw carbon out of the atmosphere seem attractive for several reasons: they are "nature-based," and they can deliver co-benefits such as conserving and restoring ecosystems, improving agricultural productivity, and supporting rural communities. Removing and storing carbon — in the oceans, in soils, in trees — is therefore quickly becoming a big business. Yet amidst the excitement and rush towards implementation, thorny questions about scale and reliability remain difficult to answer. Evading these problems could undermine potentially viable approaches, or, worse yet, lead to major investment in technologies that prove to be false promises — undermining already fragile public trust in science. This talk will argue that the current path, crowded by a growing flurry of technical studies, needs a stronger underlying scientific framework, and will suggest some elements of such a framework. I will briefly review the rationale for negative emissions and introduce some of the noteworthy approaches for environmental carbon capture. I will show an analysis of the scale of intervention required for these approaches to meaningfully contribute to the climate change problem — viewed in terms of time, space, material flows, and carbon fluxes. These perspectives illuminate both the potential and challenges of environmental carbon capture. I will then discuss the specific challenges of tracking carbon through open environmental systems, arguing that the canonical adoption of "verification" is problematic in complex and dynamic systems where fluxes are difficult to isolate and quantify. While engineering systems can often rely on controlled boundaries and direct accounting, environmental systems are characterized by heterogeneous processes, long timescales, and aleatoric and epistemic uncertainties. Questions of additionality, permanence, leakage, and verification therefore become fundamentally scientific questions rather than merely operational ones. I will suggest that theoretical approaches to probabilistic assessment — such as those honed over decades in analysis of natural hazard and risk — offer ways to move beyond carbon accounting alone toward a more rigorous framework not only for assessing whether carbon has been stored, but for determining what evidence would be sufficient to demonstrate durable and scalable climate benefit. This skeptical perspective is not an outright rejection of carbon removal; rather, it is a call for scientific approaches commensurate with the scale of claims being made.