Focus on Negative Emissions Scenarios and Technologies
The latest IPCC Assessment Report (AR5) concludes that achieving climate stabilization at safe levels (i.e., below 2°C) will require sustained emission reductions, leading to near-zero or negative emissions (NE) towards the end of this century. During the past decade, however, emissions from fossil fuel combustion and cement production have continued to rise. Emissions in 2013 reached 10 Pg C year-1, a 61% increase compared to the 1990 value. Keeping global average temperature below 2°C or higher average temperatures in a cost-effective manner will require a suite of mitigation options, particularly if mitigation is delayed further. One option increasingly invoked in integrated assessment models (IAMs) is negative emissions, defined as the net removal of CO2 from the atmosphere. Two of the most commonly proposed alternatives are biomass energy with carbon capture and sequestration (BECCS) and direct air capture (DAC). However, little is known about the global potential of emerging and future negative emissions technologies, the sustainability and cost of large-scale deployment needed to meet "safe" climate stabilization targets, and the carbon-climate feedbacks of entering a new carbon-negative world. These knowledge-gaps are the focus of a proposed Environmental Research Letters special issue:
- Available, emerging and future negative emissions technologies, emphasizing BECCS and DAC technologies.
- The behavior of natural land and ocean carbon sinks under a negative carbon balance.
- The sustainability of large-scale deployment relative to other goals such as food security, timber production, water availability, and biodiversity conservation.
- A specific focus on the production of sustainable Bioenergy with Carbon Capture and Storage (BECCS) globally and through research in specific regions, including Brazil; BECCS is the most-used technology in current integrative assessment models to achieve the 2°C climate stabilization target.
- Socio-institutional barriers, including governance and public acceptance, of new technologies.
- Risks and opportunities in investing heavily in research and development for NE technologies over the coming decades.