Seven Things You Should Know About the IPCC 1.5degC Special Report and its Policy Implications

The Intergovernmental Panel on Climate Change (IPCC) tonight is going to release an important report to help inform global efforts to limit climate change. The special report details the impacts of a global average temperature increase of 1.5degC relative to 2degC above pre-industrial levels, and pathways to limit temperature increase to that level. Governments of the world have come together this week in Incheon, South Korea to negotiate and agree on the report's Summary for Policymakers, which is based on the underlying science in the final IPCC report. The summary is expected to be released on Monday morning in South Korea (late on Sunday night here on the US east coast).

Here are seven things you should know about the IPCC 1.5degC report and why it matters.

#1 The origins and purpose of the report.

The IPCC special report on 1.5degC comes at the request of countries - a request that was made at the time the Paris Agreement was reached, which "Invites the Intergovernmental Panel on Climate Change to provide a special report in 2018 on the impacts of global warming of 1.5 degC above pre-industrial levels and related global greenhouse gas emission pathways" (Excerpt taken from the decision text accompanying the 2015 Paris Agreement). The timing of this report is critical because it is meant to help inform and motivate more ambitious emissions reduction commitments from countries. In Paris, nations also agreed to "convene a facilitative dialogue among Parties in 2018 to take stock of the collective efforts of Parties in relation to progress towards the long-term goal" of the Paris Agreement and "to inform the preparation of nationally determined contributions." There was an explicit recognition at the time that existing country commitments were inadequate to meet the Paris Agreement goals, and the hope was that countries would ratchet up ambition in light of the latest science detailed in the IPCC report. (UCS Climate Scientist Rachel Licker explains more about the report in her recent blogpost.)

#2 This is a consensus report that aims to capture the current state of the science.

The IPCC does not do new science, but it does synthesize and interpret the existing body of scientific literature using a consensus-based approach. By its very nature, this means that the scientific report is likely to adopt a fairly conservative approach to characterizing the risks of climate impacts. This is likely to be especially true about new, emerging risks that are only now being understood by scientists, such as some of the runaway risks or feedback loops related to the loss of land-based ice sheets or thawing permafrost. Unfortunately, some may use this as an excuse to downplay the potential for extreme risks. A sober reading of the recent science shows that unfortunately we have seen uncertainties about serious risks break the wrong way again and again. In addition, the Summary for Policymakers is a politically-negotiated text. It is meant to reflect the underlying science but there is some room for governments to make decisions about what to emphasize and what to downplay. The eyes of the global scientific community will be on this summary to make sure that it doesn't water down or misinterpret the science.

#3 Will there be surprises in the report?

The report will compare impacts of warming at 1.5degC with 2degC. This is the first time that the science on 1.5degC is being assembled in this manner so that in itself makes the report unprecedented. One growing cause for concern is that some major impacts are being experienced already even before the 1.5degC threshold has been crossed, as this past year of intense typhoons and hurricanes, wildfires, heatwaves and floods has shown. That means we can no longer rely on the notion of a "safe" temperature guardrail.

#4 Is 1.5degC feasible?

Unsurprisingly, the report is likely to be equivocal about the feasibility of limiting the global average temperature increase to 1.5degC. That's because any ambitious effort to limit temperature increases is a combination of scientific, technological, political, social and economic parameters. This is not just an accounting exercise about carbon budgets and emissions; it comes down to crucial choices we make right now as a global community. What's clear is that we have no time to waste in making deep cuts in global heat-trapping emissions, and unfortunately there is a very significant probability that we are likely to exceed 1.5degC given our failure to enact ambitious policies thus far. Regardless of whether or not this specific temperature target is achieved, there's no doubt that limiting temperature increases to as low as possible is as critical and urgent as ever. Every fraction of a degree we can avoid is important to limit worsening climate impacts.

#5 What will it take to seriously limit temperature increases?

The pathways to reach 1.5degC or other low temperature targets all involve a massive scale up of low-carbon energy technologies and energy efficiency. Numerous studies show that to achieve ambitious temperature targets, we have to get to net zero emissions no later than by mid-century, a fact that is likely to be echoed in the IPCC report. That means we have to not only cut emissions but must also invest in scaling up so-called "negative emissions" options. These options span a range including: afforestation and reforestation; enhanced land management practices; direct air capture; and bioenergy with carbon capture and storage (BECCS).

#6 Sustainable development and climate action are inextricably linked.

The Paris Agreement enshrines the long-term temperature goals in the context of sustainable development and poverty eradication, an important detail that is often lost in the public discourse (see Article 2). As the science underlying the IPCC report makes clear, worsening climate impacts will disproportionately affect low-income and otherwise disadvantaged communities around the world. Many of these impacts--including threats to food security and water availability, rising extreme heat, extreme precipitation and other extreme events and disasters, and loss of land--will make it even harder for people to meet their daily needs and climb out of poverty. These impacts could significantly set back investments that countries are making to improve the well-being of their people. At the same time, pollution from our dependence on fossil fuels also disproportionately affects low-income communities and communities of color. A transition away from fossil fuels to cleaner, more sustainable energy sources would bring significant near-term public health benefits to these communities.

#7 How does the report inform policy?

The IPCC is not a policy-prescriptive body and this report is specifically intended to be policy-prescriptive. But responsible governments of the world can and should make some obvious connections with policy. (See below for more on policy implications). One big takeaway from the report is very likely to be that the world is currently not on an emissions trajectory aligned with the long-term goals of the Paris Agreement, and so countries must do more to ratchet up the ambition of policies to drive down heat-trapping emissions. At the same time, some pretty sobering climate impacts are already being experienced globally, and these are likely to worsen. We'll also need policies to help people cope with the growing harms from climate change.

Policy implications of the IPCC 1.5C report

With the release of the report, governments of the world will have the information they asked for in 2015 in Paris. It's a fresh reminder, if one was needed, that current emissions reduction pledges are not enough to meet the long-term goals of the Paris Agreement. Indeed, they are not enough for any appropriately ambitious temperature target, given what we know about dangerous climate impacts already unfolding even at lower temperature thresholds. The policy implications of the report are obvious: we need to implement a suite of policies to sharply limit carbon emissions and build climate resilience, and we must do all this is in a way that prioritizes equitable outcomes particularly for the world's poor and marginalized communities.

Numerous studies show potential pathways to make deep cuts in heat-trapping emissions. Many countries, including the United States (under the Obama administration), have outlined long-term strategies to lower their emissions. It's now time to act.

We already have many of the solutions we need to limit emissions--such as ramping up cost-effective, low-carbon energy sources (like wind and solar energy) and energy efficiency and investing in carbon-friendly forest management and land use practices. We'll need to invest in technologies, processes and infrastructure to advance the (low-carbon) electrification of as many energy uses as possible, including in the transportation and industrial sectors. We also have to invest in research, development and deployment of a portfolio of the next generation of solutions--which could include advanced battery storage, zero-carbon fuels and transit options, carbon capture and sequestration, safe advanced nuclear reactors, more distributed electricity generation, and changes in diet, land use and land use management choices, to name just a few options--with the understanding that there are risks that some of these investments may not come to fruition in time or may have serious side-effects. Finally, we have to find ways to increase energy access for the millions of people in the world who still don't have access to modern energy services. An ambitious suite of solutions must be quickly scaled up globally, else we risk locking in 3.4degC or worse.

The need to invest in "negative emissions" options also raises difficult technological, socioeconomic environmental and ethical challenges. Which options will be possible to scale up in the time-frame needed, what kinds of costs and trade-offs they will involve, how should those trade-offs be weighed, and how much can these options really contribute to global efforts to limit climate change are still open questions. But there's no doubt we'll have to grapple with the realities of needing negative emissions technologies, including through inclusive scientific and stakeholder processes to properly evaluate them and appropriate policies to advance research into and the development and implementation of chosen technologies.

The costs of a rapid transition away from fossil fuels may be significant in the near term, although surely less than the ultimate costs of an unlivable planet. That's why richer nations must provide the climate finance needed by the least developed countries to make this transition swiftly. There are some who suggest a false choice between sustainable development and climate action, arguing that less developed nations need to expand fossil fuel use and carbon emissions in order to lift people out of poverty. This is a sure path to runaway emissions and dangerous climate impacts--the burden of which will fall disproportionately on developing nations. The only way out of this trap is for nations of the world to come together and make equity considerations central to how we solve the climate crisis. Yes, all people have a right to a decent standard of living, and access to energy is critical for achieving that goal. Will rich nations step up to ensure swift access to low-carbon energy globally? This is as vital a question as any about technology pathways.

Many of the world's people, today and in the future, are going to experience significant climate impacts--including worsening drought, water scarcity, flooding, heat waves and wildfires--even if we succeed in reducing emissions. The harms and loss of life, especially to those communities that are most exposed and have the least resources to cope, could potentially be immense. Policymakers also need to be thinking of the worst-case scenarios for impacts like sea level rise to help communities prepare well ahead of time, as well as factor climate projections into plans for long-lived investments in critical infrastructure. Richer nations, that have benefited from a lion's share of the carbon budget consumed to date, have a responsibility to help developing countries cope with these worsening impacts, including by providing funding for resilience measures and real pathways for people to move out of harm's way.

As the next annual meeting of the UNFCCC draws close, to be held Dec 3-14 in Katowice, Poland, governments must now grapple with the next steps in implementing the Paris Agreement, as my colleague Alden Meyer describes in his blog. In the context of this IPCC report, they must detail how they intend to create a process for increasing emissions reduction pledges from countries and increasing the levels of climate finance for developing nations over the next two years and beyond--all with a view to limiting the harmful effects of climate change.

By 2020 at the latest, the global community must agree on an enhanced action plan and more ambitious, firm, national commitments for achieving the goals of the Paris Agreement, if we are to have any chance of coming close to them.

Our choices (still) matter

The choices we must make now are daunting. We are in a world of trade-offs. Some of the solutions we may need to rely on won't be cheap. And they may come with adverse environmental or socioeconomic consequences or unknown risks that will have to be weighed relative to climate risks. We no longer have the luxury of pure win-win choices.

How we make these choices is also important. We need to be clear-eyed about risks and trade-offs. We need to engage a diverse set of stakeholders from the global community in making key decisions. And we cannot afford to delay action any longer.

Here in the United States, it is a time of deep concern with the Trump administration rolling back every national climate policy, stepping away from the Paris Agreement, and working on every front to undermine international cooperation. It's going to be up to states, cities, tribal communities, faith leaders, labor and environmental justice leaders, youth groups--ordinary Americans from all walks of life--to pick up the baton and do our part to contribute to global efforts to limit climate change.

Whether or not we are able to limit temperature increases to 1.5degC, the task ahead is crystal clear: cut emissions as much as possible and invest in resilience to projected climate impacts everywhere in the world. The eternal question remains: will policymakers step up and do what's needed to make this a reality in a time-frame commensurate with the urgency of the climate crisis?

Our children and grandchildren's futures depend on the choices we make today.