The IPCC Report Does Not Give Us Much Hope

Last week, the Intergovernmental Panel on Climate Change (IPCC) released its highly anticipated Sixth Assessment Report. Labeled a “code red for humanity” by UN Secretary-General António Guterres, the latest report does not mince its words: “It is unequivocal that human influence has warmed the atmosphere, ocean and land” with many changes to the global climate system “irreversible for centuries to millennia.” This report, like the wildfires in California and the western drought, should be a massive alarm bell to our leaders in Washington, DC, and they must take immediate action to solve the worsening climate crisis.

What is the IPCC?

The IPCC is the United Nations (UN) body for assessing the science related to climate change. Created in 1988 by the World Meteorological Organization (WMO) and UN Environment Programme (UNEP), the IPCC provides policymakers with regular assessments on climate change, its implications, risks, and adaptation and mitigation options.

The IPCC does not conduct its own research, as its published reports and other documents are born out of reviews of the latest published scientific research. IPCC reports are not policy prescriptive and are shared with policymakers so that they can make informed climate policy decisions.

195 member governments make up the panel of the IPCC, with members meeting in Plenary Session at least once a year. They work by consensus to determine their work program, scope and outline of their reports, procedural issues of the IPCC, and structure and mandate of their Working Groups and Task Forces. The Panel also approves and adopts IPCC reports.

There are three Working groups and one permanent Task Force, but other task groups may be established for a set time to evaluate a specific question or topic.

• Working Group 1 — The Physical Science Basis of Climate Change
• Working Group 2 — Climate Change Impacts, Adaptation, and Vulnerability
• Working Group 3 — Mitigation of Climate Change
• Task Force on National Greenhouse Gas Inventories

What are the IPCC Reports?

The IPCC prepares comprehensive Assessment Reports about the state of the scientific, technical, and socio-economic knowledge of climate change, its impacts, future risks, and potential solutions. In addition to Assessment Reports, the IPCC produces Special Reports on topics agreed to by members of the Panel, Methodology Reports that provide technical guidance on preparing GHG inventories, and Synthesis Reports which integrate Assessment Reports and Special Reports published during an assessment cycle.

The IPCC’s publications are prepared by hundreds of scientists and other leading experts who volunteer their time and are nominated by their governments to review the latest published scientific material on climate change and communicate their findings. The composition of author teams reflect a range of scientific and socio-economic backgrounds that include a mix of male and female authors from around the world to ensure reports are not biased toward any particular region or country.

The First Assessment Report was completed in 1990 and was directly instrumental in the creation of the UN Framework Convention on Climate Change (UNFCC) in 1992. Since then, the IPCC has published five additional Assessment Reports, with its latest AR6 to be finalized sometime next year. During the AR6 cycle, there have also been several Special Reports: Global Warming of 1.5℃, the Special Report on Climate Change and Land, and the Special Report on the Ocean and Cryosphere in a Changing Climate. The report released last Monday is the first part of the AR6, produced by Working Group 1 which focuses on The Physical Science Basis of Climate Change.

Before final publication, IPCC reports must go through lengthy comment and approval processes. They are reviewed and commented on by expert reviewers and governments, who produce thousands of comments. The language of the document usually changes, as the IPCC is required to seek unanimous consent to bolster the credibility of their reports. In the past, this requirement has lead to some criticizing the IPCC as being too conservative with their findings.

What are the main points from AR6?

The AR6 report from Working Group 1 is almost 4,000 pages long, so I read the shortened Summary for Policmakers which concisely conveys the report’s main points. Many media sources, including Grist, Vox, and The Guardian, have all given their opinions on the report, and I encourage you to read their their takeaways.

Before getting into my takeaways, I wanted to mention a few things about AR6:

• The assessment covers scientific literature accepted for publication by January 31, 2021. This means that any scientific research published since then was not included for analysis in the assessment.
• The findings within the report are founded on an evaluation of underlying evidence and agreement. There are five levels of confidence expressed: very low, low, medium, high, and very high. Several terms are used to express the likelihood of an outcome occurring: virtually certain (99–100%), very likely (90–100%), likely (66–100%), about as likely as not (33–66%), unlikely (0–33%), very unlikely (0–10%), exceptionally unlikely (0–1%).
• Like all Assessment Reports, AR6 expresses the unanimous consent of the Panel and has undergone rigorous review and revisions. Historically, the language has been somewhat conservative. However, this Assessment Report, directly blames humanity for climate change, strongly attributes many climate impacts to human activity, and clearly states that emissions must reduce dramatically to prevent 1.5℃ of warming. If there was unanimous consent on using such strong language, the situation must be serious.

Humans have “[unequivocally]” created the climate crisis

The report opens with, “It is unequivocal that human influence has warmed the atmosphere, ocean, and land.” Human influence has “likely” caused global surface temperatures to rise about 1.07℃ and contributed to the pattern of global precipitation changes. It is “very likely” or “virtually certain” human activity has contributed to the decrease in Northern Hemisphere spring snow coverage, surface melting of the Greenland Ice Sheet, global upper ocean warming, global acidification of surface open ocean, and rising sea level rates. To the scientists behind the report, there is no doubt that the dramatic changes to the global climate system are directly our fault.

According to the report, atmospheric concentrations are higher than at any time in at least 2 million years, methane and nitrous oxide levels are at their highest in at least 800,000 years, and global sea level is rising at its fastest in at least 3,000 years.

There are new future warming projections, and none are encouraging

AR6 includes five new emissions scenarios called shared-socioeconomic pathways: very high GHG emissions (SSP5–8.5), high emissions (SSP3–7.0), intermediate emissions (SSP2–4.5), low emissions (SSP1–2.6), and very low (SSP1–1.9). All of these scenarios reveal that global surface temperatures will continue to rise until at least mid-century, with the low and very low emissions scenarios our only chances of staying under 2℃ of global warming. Unfortunately, we are nowhere near achieving the low or very low scenarios.

Scientists also better understand how the planet responds to the concentration of GHGs in the atmosphere, so their predictions are becoming more accurate. The equilibrium climate sensitivity, which is the long-term temperature rise should atmospheric GHG concentration double, is estimated at 3℃.

The impacts will be global, but they will vary regionally

Although all regions will experience further increases in hot climatic impact-drivers, certain regions will face more dramatic impacts than others due to geographic variability and other factors. For example, the report more confidently states that heavy precipitation and flooding will occur in Africa and Asia (high confidence) than in Europe (medium confidence). Several regions in Africa, South America, and Euripe will experience an increase in frequence and/or severity of droughts. Regions characterized by permafrost, glaciers, snow, and ice will see continued melting, while ⅔ of coastlines may see sea level rise within +/-20% of the global mean increase.

You can explore spatial and temporal impacts using the new WGI Interactive Atlas.

Many climate impacts, primarily sea level rise, are irreversible for centuries or millennia

However you look at it, the report’s findings do not pose well for coastal communities or regions reliant on snowpack for water supply in spring and summer months. Past GHG emissions have committed the oceans to future warming no matter our course of action, with continued sea level rise “virtually certain”. Changes to global ocean temperatures, deep ocean acidification, and deoxygenation are irreversible for centuries or millennia. Melting glaciers and permafrost loss are also irreversible at centennial timescales. Despite the certainty regarding sea level rise, there is lower confidence concerning the amount of sea level rise due to uncertainty in ice sheet processes.

We can decide our fate if we quickly reduce emissions

AR6 confirms that there is a near-linear relationship between cumulative anthropogenic GHG emissions and global warming, with each 1000 GtCO2 likely causing 0.45℃ pf warming. Therefore to reduce further temperature increase to a certain level would similarly require reducing GHG emissions within a carbon budget. The report confirms that we are too late to go back to the world of yesterday, but it provides some hope that there is still time to mitigate climate change and save the planet.

What does the report means for COP26?

COP26 is the 2021 UN climate change conference that will be taking place in Glasgow, Scotland this November. Like during COP21, when the Paris Agreement was created, thousands of government representatives, businesses, and citizens will come together to reach agreement on how to prevent runaway climate change. The findings of the AR6 report will be integral to their negotiations.

As UN Secretary-General Antonio Guterres said, the Working Group 1 report must represent the “death knell for fossil fuels,” and our political and business leaders must recognize that fact and act aggressively. We cannot stall any longer on issues such as decarbonizing the power or transportation sectors, and we must figure out how to lower emissions even while trying to lift millions of people out of poverty.

This report also reaffirms that we must simultaneously invest heavily in resiliency measures as rising temperatures, increasing sea levels, and other impacts are guaranteed to strengthen. Many countries cannot afford the necessary resiliency investments, and some countries may even cease to exist as they are erased from the map or thrown into chaos due to climate pressures. World leaders must decide how to share the burden of the climate challenge and render aid where needed.

If you thought the last climate change conference was important, this one is even more so. The Paris Agreement was ambitious, but AR6 requires our leaders to go even further to reduce emissions and transform global society. Unfortunately, the success of this conference is in doubt even before it can begin, as there are persistent and new threats facing the world. The pandemic continues, threatening whether the conference will even take place, and the fall of the Afghanistan government to the Taliban have heightened global security tensions.

As Doug Parr, chief scientist at Greenpeace UK, commented, “This is not the first generation of world leaders to be warned by scientists about the gravity of the climate crisis, but they’re the last that can afford to ignore them.”