Conference report: An international conference on negative emissions highlights extent of trade-offs and reinforces urgency of near-term emission reductions.
Hansen expressed skepticism that we can remove emissions from the atmosphere cost-effectively at scale, and warned of the moral hazard that promising this technology in the future will delay action now. Hansen used his keynote to communicate the urgency of the climate crisis – outlining two imminent threats facing humanity: the inertia in oceans and ice-sheets, meaning we are close to the point of handing young people a situation where sea-level rise is out of their control; and mass species exterminationsdue to poleward movement of climatic zones at a rate beyond which species can adapt to.
Anders Lyngfelt of Chalmers University of Technology, hosting the conference, finished up the opening keynotes by describing negative emissions as a question of balance – arguing it is irresponsible to base climate policy on future negative emissions, but we are now in a situation where it is irresponsible not to remove CO2 from the atmosphere. Lyngfelt suggested that trying to do this will make apparent the real costs of releasing CO2 into the atmosphere for free.
The majority of presentations ended with the reminder that there is no way around deep emissions reductions, indicating perhaps a consensus in the governance of negative emissions – that they are only part of a climate mitigation strategy when used in addition to, and not instead of, deep emission reductions. The message that removing CO2 from the atmosphere does not compensate for ongoing emissions was a key takeaway from the conference.
Others argue that more attention must be paid to the environmental impacts of large-scale CO2 removal, and that the CBD considers most, if not all, tech­niques for CO2removal to be climate geo­engineering.
Pete Smith from the University of Aberdeen presented a new paper showing the impacts on biodiversity when moving from a 2°C world to a 1.5°C world, including impacts from mitigation measures. Smith also highlighted how a recent paper on natural climate solutions has caught the attention of policy makers because it offers more simple, natural solutions than the negative emissions technologies – but Smith questioned whether natural solutions gets us to where we need to be to hit the 2°C or 1.5°C target, suggesting 'nastier' forms of CDR would also be needed.
Oliver Geden made the point that 'natural climate solutions' sells politically – they are good things to do anyway – and Green parties, environmental movements and the public can get behind net-negative emissions if it is based on natural solutions. However, the distinction between natural and 'unnatural' climate solutions was often blurred, or missed entirely, with afforestation / reforestation (A/R) and ecosystem restoration being used interchangeably in many presentations, not to mention in integrated assessment models. The need to distinguish between BECCS and A/R, with negative environmental and social impacts, and ecosystem based solutions that bring real benefits for and biodiversity, has never been more important.
Silke Beck of the Helmholtz Centre for Environmental Research spoke of how the IPCC serves as a site of de facto governance, and the risks of promoting unfounded hope in negative emissions. Beck outlined how integrated assessment models have legitimized the concept of negative emissions, thereby transforming models into tools for policy making – making what were sometimes previously unthinkable notions mainstream and acceptable. Beck argued that the presence of BECCS in models makes a BECCS colored future more likely, with a slippery slope between a 'possible' pathway and political reality where these essentially 'speculative' technologies are considered the only 'feasible' way to meet climate targets, while other options labeled 'not feasible' are off the table.
In a panel discussing modelling, policy and incentives, Detlef van Vuuren from the Netherlands Environmental Assessment Agency said the amount of net-negative emissions are not a given – we can reduce reliance on carbon removals (and even eliminate it), but he argued that this doesn't make the transition any easier, as alternative mitigation pathways to BECCs are also challenging, requiring major behavioral changes in addition to zeroing out fossil fuel emissions. Van Vuuren concluded that an open discussion around negative emissions is urgently needed, as so far this has been too implicitly embedded in models.
Naomie Vaughan of the University of East Anglia and the Tyndall Centre for Climate Change Research suggested that it is not about the right amount of hope versus fear, it is about being honest – we are talking about trade-offs – stop flying or negative emissions? Reduce meat consumption or negative emissions? Vaughan suggested desirability rather than feasibility may be a framework to think about the future we want.
During the panel discussion Hansen pointed out that fossil fuels are currently subsidized – the costs are not paid to society. If the cost of getting carbon out of the atmosphere was attached to putting it there, we would understand that it makes more sense to reduce emissions, than to pay $400 – $500 billion per year to extract it. Hansen admitted that scientists have not done a good job so far of communicating the urgency of climate change, but felt that the 'solutions' coming out of integrated assessment models will not do anything to move us off the path we are on. Hansen suggested we are not going to reduce global emissions as long as fossil fuels are allowed to be cheap, and there has been a complete lack of leadership on this problem.
The issue (and irony) of negative emissions scale-up being reliant of the fossil fuel industry was not lost. One speaker noted that if we shut down the fossil fuel industry, competence for storing emissions underground will be lost. Sally Benson of Stanford University, in a keynote on geological storage, made the point that to achieve a reduction in CO2 emissions, long-term storage is key, concluding: "If we are interested in negative emissions, we probably shouldn't be looking at enhanced oil recovery".
The conference aimed to look at how negative emissions can become a reality at scale – but in reality, the scale question is fraught with challenges. The dialogue and debate that occurred was valuable in making clear the stark choices society faces: while the scale of a technology such as BECCS in modelled pathways may rightly be criticized as speculative, the reliance of a 1.5°C temperature limit on removing (some amount of) CO2from the atmosphere is also a necessity. The conference highlighted the fact that there is no escape route from reducing emissions – the challenge before us is to limit reliance on carbon removals to levels that can be achieved through options that benefit, rather than undermine, people, biodiversity and food systems.
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