The recent report of the Intergovernmental Panel on Climate Change (IPCC) is a valuable wake-up call. While the climate community finds few breakout bulletins, just a reiteration of the grave situation the world faces, the news coverage of the report is important.

The new report is the first of three that comprise the IPCC’s Sixth Assessment Report (AR6). They carry weight: the IPCC is the leading international scientific authority on climate, established by the UN, with 195 countries as members. Each report has an “author team” numbering 230-270 individuals. Here are some highlights.

Working Group 1: Climate Change 2021: The Physical Science Basis (August 2021). A straightforward accounting of what’s happening to the planet, the role of human influence, and possible climate futures. You can choose to read the full 3,949-page text, a more manageable 40-page Summary for Policymakers, the user-friendly 2-page set of Headline Statements, or the plain spoken press release that bears the headline “Climate change widespread, rapid, and intensifying.”

Press Release Excerpts: “Scientists are observing changes in the Earth’s climate in every region and across the whole climate system. … Many of the changes observed are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years. … However, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize. … Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach. …  For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health. … Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and ocean. … The evidence is clear that CO2 is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.”

Summaries and commentaries are everywhere. One coherent and engaging presentation is this 7-minute video by Miriam Nielsen, a knowledgeable video journalist. For wisdom from a climate crusader, read Bill McKibben’s brief assessment of the report’s implications in the context of the ongoing fight for change: “It’s clearly designed to goose us into action, preferably over the eighty days remaining until the world convenes at the Glasgow climate conference.”

Coming in 2022 are reports by Working Group II, Impacts, Adaptation and Vulnerability, (Feb. 2022) and WG III on Mitigation of Climate Change (March 2022) (timelines subject to change). Here the IPCC turns from climate conditions to human repercussions and responses.

Working Group II—Impacts, Adaptations, and Vulnerability—has an ambitious set of topics (here’s the outline). It seeks to document the risks to multiple “systems,” both ecological (freshwater ecosystems; oceans and coasts; water resources; food, fiber, and other ecosystem products) and human (cities, settlements and key infrastructure; health, wellbeing and the changing structure of communities; and poverty, livelihoods and sustainable development). The goal is to present options for adaptation and for “creating a sustainable, resilient and equitable future for all.”  

Working Group report III—Mitigation of Climate Change—“focuses on climate change mitigation, assessing methods for reducing greenhouse gas emissions, and removing greenhouse gases from the atmosphere…. It will assess the range of available mitigation options in energy and urban systems, and in sectors such as agriculture, forestry and land use, buildings, transport and industry.”  While the Working Group does not advocate any specific mitigation options, it seeks to inform decisions: “It addresses all aspects of mitigation including technical feasibility, cost, and the enabling environments, that is, policy instruments, governance options and social acceptability.” The full outline can be read online.

We are already seeing concerns that the Working Groups’ calls for action will be watered down, particularly by governments in the developed world. For this reason, according to news reports, a small group of scientists decided to leak the draft of the WGIII report. Resistance to the conclusions and implications is likely: rich people in every country are overwhelmingly more responsible for global heating than the poor; the high-carbon basis for future economic growth cannot be sustained; lifestyle changes will be necessary, particularly in rich countries and among the wealthy globally, such as refraining from over-heating or over-cooling homes, walking and cycling, cutting air travel and using energy-consuming appliances less; eating patterns in many parts of the rich world need to shift to diets with a higher share of plant-based protein; and massive investments are needed to shift the global economy to a low-carbon footing. They’re talking to us.

The current IPCC cycle, Assessment Report 6 (AR6), also includes special reports: Global Warming of 1.5°C (2018); The Ocean and Cryosphere in a Changing Climate (2019); and Climate Change and Land (2020). The entire endeavor will conclude in fall 2022 with the AR6 Synthesis Report. Let’s hope that this tremendous volume of information and insight will underlie progress, and that words will, indeed, matter.