The escalating use of fossil fuels in material production presents a significant and underrecognized climate challenge. While the burning of fossil fuels for energy understandably dominates climate discussions, a recent study reveals a concerning trend: the amount of fossil-derived carbon embedded in buildings, products, and infrastructure is growing faster than the emissions from burning fossil fuels. This “technosphere” of human-made materials, from plastics in appliances to bitumen in roads, acts as a massive carbon sink, storing billions of tons of fossil carbon. This accumulation represents a “ticking time bomb,” as the eventual degradation and disposal of these materials will release their stored carbon back into the atmosphere, adding to the already pressing burden of greenhouse gas emissions.
The study, spanning 1995-2019, quantifies this alarming trend. Over this period, 8.4 billion tons of fossil carbon were incorporated into the technosphere, while only 3.7 billion tons were released back into the environment through landfill, burning, and other waste streams. This rapid accumulation is driven by the increasing complexity of manufactured products, which often require larger quantities of fossil fuel-based materials like plastics. Furthermore, the share of fossil carbon going into products has increased from 5% to over 7% of total fossil fuel usage, highlighting the growing reliance on hydrocarbons for material needs, even as some countries strive to decouple economic growth from fossil fuel energy. This trend is particularly concerning given the already record-high levels of carbon emissions from fossil fuel combustion.
The research underscores the significant role of plastics in this growing carbon stockpile. Synthetic rubber and plastic products, derived primarily from oil and gas, now constitute 30% of the fossil carbon locked within products and infrastructure. When combined with the rubber and plastics used in machinery, these materials account for over two-thirds of the fossil carbon stored in long-term products, both in households and industry. This heavy reliance on plastics is not accidental. As the world transitions away from fossil fuels for energy, oil and gas companies are actively seeking alternative markets for their products, pivoting towards the production of non-fuel products, particularly plastics, to maintain profitability. This strategic shift further exacerbates the problem of accumulating fossil carbon in the technosphere.
This accumulating carbon store represents a significant and largely overlooked climate risk. While substantial focus is placed on reducing emissions from burning fossil fuels, the embedded carbon in our material world has received far less attention. This research highlights the urgent need for a comprehensive approach that addresses both the production and disposal of fossil fuel-based materials. The authors emphasize the importance of a “reduce, reuse, recycle” waste hierarchy, calling for reduced consumption, especially in wealthy nations, improved landfill management to minimize carbon leakage, extended product lifespans, and increased recycling to reduce reliance on virgin fossil carbon. These measures are crucial for mitigating the potential future release of this stored carbon.
Beyond individual actions, systemic changes are essential. The researchers advocate for the implementation of robust material accounting systems at both national and international levels. Current carbon emissions inventories primarily focus on combustion emissions, neglecting the significant contribution of fossil carbon embedded in products. A more comprehensive accounting system is necessary to accurately track the full lifecycle impact of fossil fuels, including their use in material production. This improved understanding of material flows will be vital for informed policy decisions and effective climate action. Furthermore, collaborative international efforts are crucial. The recent failure to reach an agreement on a global plastics treaty underscores the challenges in coordinating global action on this issue. Overcoming industry influence and prioritizing environmental concerns are crucial for achieving meaningful progress in curbing plastic pollution and the associated accumulation of fossil carbon.
The findings of this study reveal a critical gap in current climate mitigation strategies. While the transition to renewable energy is essential, addressing the growing reservoir of fossil carbon in the technosphere is equally crucial. Ignoring this accumulating “ticking time bomb” risks undermining efforts to stabilize the climate. A multi-pronged approach encompassing reduced consumption, improved waste management, increased recycling, and comprehensive material accounting is essential to tackle this emerging challenge and prevent the release of vast amounts of stored carbon into the atmosphere. International cooperation and robust policy frameworks are paramount in navigating this complex issue and mitigating the long-term climate impact of fossil fuel-based materials.
