As part of the Paris agreement, the International Panel on Climate Change (IPCC) was asked “to provide a special report in 2018 on the impacts of global warming of 1.5 [degrees Celsius] above pre-industrial levels and related global greenhouse gas emission pathways.” That report was released on October 8.
The report’s “Headline Statements” are divided into four main sections: 1.) “Understanding Global Warming of 1.5 [Degrees Celsius]”; 2.) “Projected Climate Change, Potential Impacts and Associated Risks”; 3.) “Emission Pathways and System Transitions Consistent with 1.5 [Degrees Celsius] Global Warming”; and 4.) “Strengthening the Global Response in the Context of Sustainable Development and Efforts to Eradicate Poverty.”
What the Report Says and Does Not Say
In the first chapter, the IPCC points out that human activities have already caused about 1 degree Celsius (1°C) of warming, and that we will reach 1.5°C between 2030 and 2052 at the current pace. They state that what has already been emitted into the atmosphere will result in ongoing warming, sea-level rise and other effects for “centuries to millennia” (even in the absence of ongoing and future emissions), but that the emissions to date on their own will not raise temperatures to 1.5°C. So, the good news then is that reaching and sustaining net zero emissions, even at this late stage in the game, would “halt warming on a multi-decadal time scale.” The IPCC also concludes that impacts generally would be less at a 1.5°C stabilization than a 2°C stabilization.
These numbers are convenient for discussion, but realistically, the atmosphere is not like the thermostat in our living room, where we can simply dial and set in order to heat the house to some desired level. We are not in control for the most part. It is also worth keeping in mind that the IPCC has consistently underestimated the pace and magnitude of global warming. It is probably safe to say that this is still the case. Feedbacks and “tipping points” are not some distant thing to avoid, they are already happening, and their trajectory is impossible to predict. They include things like soil respiration, melting permafrost, warming and acidification of the oceans and loss of ice. The IPCC has shifted its assessments of the warming potential of methane to consistently use the 20-year timeframe comparison with CO2 [carbon dioxide], and revised upward the quantity of methane released by livestock, just as one example. There are most likely some major sources of emissions we are not even aware of. Further, there are some major sources of emissions we are aware of, but have been granted exclusion from consideration, such as the vast quantity of emissions from military activities.
Assessing climate change is a monumentally challenging endeavor, and the IPCC deserves credit for tackling it, but we cannot expect that its analysis will be 100 percent accurate and perfectly predict the future. A precautionary approach would have to lead to the conclusion that it is unacceptable to continue to emit any more greenhouse gases whatsoever. We are already bearing witness to tipping points and feedbacks we cannot control or even measure. Moreover, we know that there is a lurking and latent inevitable warming associated with greenhouse gases already released into the atmosphere. In sum, we do not have any remaining “carbon budget,” and we should be doing everything humanly possible to halt emissions altogether and immediately. That may sound “wishful,” but should in fact be our level of ambition.
Whether or not we can predict or control the future temperature rise, we clearly should put everything possible into doing whatever we can to minimize the impacts. For all but a few, there is little point in standing around watching and measuring the unfolding disaster. We need to take action, which is why the focus for most should be on the IPCC’s third chapter: “Emission Pathways and System Transitions Consistent with 1.5°C Global Warming.”
Can We Overshoot the Target and Clean Excess Carbon Out of the Atmosphere?
The IPCC uses “integrated assessment models” for their analyses. Those models plug in a suite of assumptions about changes in energy production and use, land use change and other factors, and then use those to provide trajectories (pathways) to a goal — in this report, either 1.5°C or 2°C of warming. Those trajectories are not always straight lines from here to there. Many — in fact, most of them — involve exceeding thresholds for greenhouse gas concentrations in the atmosphere in the near term, with the intention of somehow later removing the excess. This is called “overshoot.” It is an extremely risky proposition. Earlier drafts of the report did not even evaluate models that did not include overshoot to some degree. Fortunately, the final draft does evaluate pathways without or with limited overshoot.
Enabling overshoot is especially problematic because there is currently no technology available for removing carbon dioxide from the atmosphere. The IPCC points to potential use of “BECCS,” which refers to bioenergy with carbon capture and sequestration. BECCS is currently nonexistent, technically unlikely to ever become viable, and in any case, would require such a massive supply of biomass as to result in conversion of lands currently in agriculture or natural ecosystems to grow crops and/or trees for biomass. That is directly the opposite of what many would consider the most promising approach — restoring and protecting natural ecosystems. A much-welcomed feature of the report is that it offers a “BECCS-free” pathway, and goes even a step further to call for a reduction in bioenergy use generally. Perhaps that turnaround (at last) reflects the mountains of peer-reviewed literature showing that burning trees for electricity or converting land for corn ethanol is anything but a solution to climate change.
There is a huge array of potential pathways that involve the restoration of degraded ecosystems and changing agricultural practices. The IPCC recognizes these, but treats them in a muddled and superficial way. A forthcoming report (to be released on October 15) from a broad coalition of groups known as the Climate Land Ambition Rights Alliance (CLARA) outlines the potential for holistic approaches to ecosystem protection and restoration, including shifting practices in agriculture and forestry for drawing down carbon from the atmosphere. The authors reject risky techno-fixes such as BECCS and state correctly: “The battle against climate change is inseparable from efforts to ensure food security, protect human rights, plus protect and restore natural ecosystems.”
Similarly, the Global Forest Coalition recognizes that Indigenous peoples’ and local community conserved territories and areas comprise between 12 and 22 percent of Earth territory, and that full legal recognition of the rights and effectiveness of their long-term stewardship of lands and biodiversity is key. A Community Conservation and Resilience Initiative report released in 2018 highlights key examples of community conservation and assesses how those can best be supported to ensure that biocultural diversity is preserved. The report finds that local, bottom-up, participatory efforts to protect lands are most effective.
In contrast, the IPCC analyses are a top-down process, which works well in the context of assessing global and regional impacts of warming. But ultimately, when it comes to advising the world about “what to do” about climate change, the IPCC simply does not have the democratic structures in place to provide technology assessments. They have recently even embraced consideration of the ultimate risky techno-fix approach: climate geoengineering, which involves spewing sulfate particles into the stratosphere to reflect sunlight back out into space, which proponents aim to test in open air over the coming year. Such climate geoengineering approaches are highly risky and unproven, and are far more likely to worsen rather than improve conditions.
The choice of authors plays a significant role in shaping the nature of IPCC reports. The emphasis on maintaining economic growth and minimizing costs of mitigation reflects the engagement of many economists and physicists. The somewhat garbled manner in which IPCC addresses ecosystem-based approaches reflects a lack of engagement of ecologists.
In May 2017, a letter to the IPCC chair from 108 civil society organizations expressed deep concern over the selection of authors who are or were senior employees from major oil companies (ExxonMobil and Saudi Aramco), the second- and third-largest corporate emitters of greenhouse gas emissions worldwide. The letter pointed out that Exxon holds the most patents and financial interests relating to carbon capture and sequestration (or “clean coal” technology) of any company worldwide, and has, to put it mildly, blatant conflict of interest.
Ultimately, it is increasingly clear that the real solutions to climate change are not global-scale techno-fixes, but rather the locally adapted and locally controlled solutions that people have been pushing for decades, including preventing buildout of fossil fuel infrastructure, protection of lands, respect for rights of humans and nature. The ruthless pursuit of corporate wealth and power and economic growth at all costs stifles those local, grassroots solutions from reaching fruition.
Perhaps we are past the point of limiting warming to levels that will avert serious consequences. We already are witnessing those, and clearly our progress toward making change is far too slow. But that is no reason to stop working for change, and there is reason to feel a bit hopeful that we can certainly do many things to lessen the damage. A key step will be to halt the ongoing destruction of ecosystems, recognize and protect the rights of those who are good stewards of land, and shift our agriculture and forestry practices and our diets. These will need to go hand-in-hand with other kinds of changes, especially in the energy sector. Further, let’s not forget the elephant in the room — the US military. The task can feel overwhelming, but with so much at stake, how can we do anything other than try our absolute hardest?