Overshooting 1.5°C is now “almost inevitable,” but can be temporary, with temperatures returning to 1.5°C by the end of the century if countries immediately and dramatically reduce their greenhouse gas emissions – and remove CO2 from the atmosphere.
The Intergovernmental Panel on Climate Change (IPCC) issues an assessment every six or seven years comprising three installments. The most recent is the Sixth Assessment Report (AR6). The first instalment, published in August 2021, laid out the latest evidence for manmade climate change. The second, published in March 2022, described how climate change is likely to affect us. The third and final instalment, published in April, assesses what we are – and should be – doing about it.
Typically, the reports make headlines with their stark warnings. For example, the first instalment rang through news outlets with its ‘code red for humanity’ slogan. Current events including the cost of living crisis and Ukraine-Russia war risk drowning out the latest report, but they also serve as a vivid reminder to policymakers of the obligation to act.
“The spotlight is on major emitting countries to take steps [to meet climate targets] this year without delay,” says Tom Evans, a climate diplomacy policy advisor at think tank E3G. “It’s not only what they promised to do at last year’s COP26 UN climate summit, but also what today’s report urgently calls for.”
Accepting the inevitable
With current policies, global warming of between 2.2 and 3.5°C is expected within the next 80 years. While the growth rate of emissions between 2010 and 2019 was slower than the decade before, global anthropogenic emissions continue to rise across all major greenhouse gases.
The report asserts that for just a 50% chance of restricting warming to 1.5°C, the world needs to halve global CO2 emissions by 2030. This being a possible but unlikely scenario, the IPCC gives readers reason not to despair with a mitigation plan that can return warming levels back to 1.5°C after they have surpassed it.
There are far too many coal plants, gas installations and other fossil fuel projects in the works, according to the report. The IPCC stresses that the only realistic scenarios for keeping within 1.5°C involve the entire phase-out of coal and on top of that, the use of technologies for CO2 removal from the atmosphere.
A first for direct air capture
Carbon capture and storage (CCS) has long been part of net-zero roadmaps. Policymakers have supported CCS for its potential to decarbonise heavy industry, build a clean-hydrogen economy ("blue" hydrogen is made from natural gas with CCS) and deliver on net-zero goals. Yet while CCS has been around for a while, it has struggled to achieve commercial viability. The latest IPCC report may change that.
While the report mentions the importance of preserving existing forests, peatlands and other natural carbon stores – whilst growing new forests and restoring soils and landscapes – no amount of tree planting will suffice to negate the massive output of continued fossil fuel emissions.
Climeworks is a Swiss company providing direct air capture (DAC) technology to suck CO2 back out of the atmosphere, and in partnership with Carbfix in 2021, it massively scaled up its Iceland DAC plant to launch the world’s first large-scale carbon dioxide removal plant. Powered entirely by renewables, the technology sequesters carbon from air and stores it underground where it is eventually mineralised. The plant removes up to 4,000 tonnes of CO₂ from the air every year.
All emissions pathways compatible with 1.5°C rely on a massive scale-up of carbon removal – to the point where removal rates exceed residual emissions.
“[The report] reconfirms the need to remove CO2 from the air, and for the first time, the IPCC released specific estimates for required direct air capture volumes,” says a spokesperson for Climeworks. “It sends a clear signal to the world that we need to scale up direct air carbon capture and storage (DACCS) and fast.”
“The modelled pathways that limit global warming to 1.5°C with no or limited overshoot require up to 310 gigatonnes of DACCS by 2100. The challenge ahead of us is large, but momentum is with us, and we are ready to tackle it more than ever.” Just as the IPCC’s report came out, Climeworks announced it had raised $650m, by far the largest equity raise by any carbon removal company to date.
CO2 removal and reduction
While carbon dioxide removal (CDR) offers redemption to an otherwise bleak forecast, the authors of the latest IPCC report warn the technology “cannot serve as a substitute for deep emissions reductions”.
There are no pathways in the report where a scale-up of CDR alleviates the requirement for major emissions reductions and the authors emphasise “the emission reduction via more conventional mitigation measures (e.g. energy efficiency, grid decarbonisation) is much larger than the CDR contribution”.
The authors also warn that the promise of carbon removal risks driving inaction on decarbonisation: “The prospect of large-scale CDR could […] obstruct near-term emission reduction efforts [and] mask insufficient policy interventions, [leading] to an overreliance on technologies that are still in their infancy.”
Director for risk and resilience at E3G Taylor Dimsdale shares these concerns. “The latest IPCC report shows that [CDR] won’t be a panacea. To avoid worst-case scenarios and unmanageable impacts, the promise of negative emissions at some future point in time must not be used as an excuse to delay action on efficiency and the deployment of renewables now.”
BECCS: food versus fuel
DACCS is just one type of CDR technology named in the report, with most scenarios actually relying on bioenergy with carbon capture and storage (BECCS). Bioenergy has been criticised for putting strain on an already struggling global food supply, however. As a result, experts have concerns over the IPCC report’s focus on BECCS as a crucial means to limit warming.
“Prior to AR6 being released my main concern was that we need to minimise our reliance on commercially unproven carbon dioxide removal technologies like BECCS,” says Daniel Quiggin, a senior research fellow in the Environment and Society programme at Chatham House. “It was scary to see the level of BECCS reliance within AR6. With emphasis on BECCS feedstocks derived from agricultural land rather than forest-based biomass feedstocks, the risk is these biocrop feedstocks compete with land food production, and consequently push up food prices and decrease food availability.”
Quiggin suggests two ways to “square this circle”. The first is to decrease meat consumption and massively scale up food production yields. The second is to lower reliance on BECCS and CDR in general by focusing on demand reduction for energy and food.
“If we globally scale up BECCS, the demand for wood [on top of agricultural feedstocks] could lead to more deforestation,” he says. “At COP26, we saw governments act on the vital role that natural forests play in stabilising climate change, committing to halt and reverse deforestation by 2030. Putting BECCS into the mix could compromise this pledge.”
Experts have had myriad reactions to the latest instalment from the IPCC, but across the board they seem to agree on one thing: energy demand and consumption will be the death of us.
“Now more than ever, the world needs to double down on decarbonising the energy sector, which is responsible for three-quarters of global carbon emissions,” says Jonathan Held, a senior researcher on global energy policy at E3G. “Clear timelines and commitments for accelerating energy efficiency, clean energy deployment and fossil fuel demand reduction are needed this year to improve global resilience and ensure the world stays within the global carbon budget.”