IPCC AR6 wg2 report summary

The Intergovernmental Panel on Climate Change (IPCC) working group 2 (wg2) released its sixth assessment report (AR6) at the end of February: the IPCC AR6 wg2 report. Now you know what all those acronyms mean 😉 Of course, the news has been dominated by the Russian invasion of Ukraine but, as discussed in the last post, the two issues are linked – both can be addressed if the world were to impose strict energy sanctions against Russia and transition more rapidly to renewable energy.

The IPCC has three working groups: Working Group 1, dealing with the physical science basis of climate change; Working Group 2, dealing with impacts, adaptation and vulnerability; and Working Group 3, dealing with the mitigation of climate change. I summarized the IPCC wg1 report after it came out in August 2021; the wg3 report is due around April 2022.

The IPCC AR6 wg2 reports are available here – the Summary for Policymakers is 36 pages, the Technical Summary is 96 pages and the full report is 3675 pages.

 The assessment report is the sixth since the IPCC was first convened by the UN in 1988, and may be the last to be published while there is still some chance of avoiding the worst. – The Guardian.

OK – that’s a lot of information, but these are arguably the most important reports that civilization has ever produced. That’s why it pains me a little bit to say that the Summary for Policymakers, which is likely to be the only document that most folk look at, is a snooze fest. And, faced with catastrophic climate change, there’s one thing we’ve been doing too much of, lately: snoozing.

IPCC AR6 wg2 Summary for Policymakers

My main problem with the IPCC AR6 wg2 Summary for Policymakers is that the language is often too vague (maybe trying too hard to be apolitical) and the format is tedious. Some of the more specific data and recommendations that were mentioned in the Technical Summary are excluded from the Summary for Policymakers. I’ll mention them at the end but first I’ll attempt distill down the Summary for Policymakers so that the message is more obvious (and I’ll add some bold for emphasis).

Climate change has caused substantial damages, and increasingly irreversible losses, in terrestrial, freshwater and coastal and open ocean marine ecosystems (high confidence). The extent and magnitude of climate change impacts are larger than estimated in previous assessments (high confidence).

…increases in the frequency and intensity of climate and weather extremes, including hot extremes on land and in the ocean, heavy precipitation events, drought and fire weather (high confidence).

Near-term actions that limit global warming to close to 1.5°C would substantially reduce projected losses and damages related to climate change in human systems and ecosystems, compared to higher warming levels, but cannot eliminate them all (very high confidence).

Climate change and related extreme events will significantly increase ill health and premature deaths from the near- to long-term (high confidence).

Below are some charts illustrating various social and environmental impacts (yellow = moderate; red = high; purple = very high) based on the mean global temperature increase. The grey line indicates where we are now – a 1.1°C increase in the earth’s surface temperature, compared to pre-industrial levels. The Paris Agreement aims to allow the mean global temperature to rise no more than 1.5°C above pre-industrial levels (or 2°C, at most).

IPCC AR6 wg2 report. Bar charts are used to show predictions for the impact of climate change on various social and environmental issues. The Y-axis of each chart is "Global surface temperature change" ranging from 0 to 4 degrees. Some impacts, such as degradation of coral reefs in Australia, are already in the very high impact zone. Several others, shift into the high or very high impact zone at around 1.5 to 2 degrees of warming.

Vulnerability of ecosystems and people to climate change differs substantially among and within regions (very high confidence), driven by patterns of intersecting socio-economic development, unsustainable ocean and land use, inequity, marginalization, historical and ongoing patterns of inequity such as colonialism, and governance (high confidence).

Projected climate change, combined with non-climatic drivers, will cause loss and degradation of much of the world’s forests (high confidence), coral reefs and low-lying coastal wetlands (very high confidence).

While agricultural development contributes to food security, unsustainable agricultural expansion, driven in part by unbalanced diets, increases ecosystem and human vulnerability and leads to competition for land and/or water resources (high confidence).

The magnitude and rate of climate change and associated risks depend strongly on near-term mitigation and adaptation actions, and projected adverse impacts and related losses and damages escalate with every increment of global warming(very high confidence).

Biodiversity and ecosystem services have limited capacity to adapt to increasing global warming levels, which will make climate resilient development progressively harder to achieve beyond 1.5°C warming (very high confidence).

So, not surprisingly, the more effort we make, as soon as possible, the less catastrophic the impact will be. Possible future scenarios are generalized in a kind of snakes and ladders game, showing that we’ve already missed opportunities to improve and also pointing out that we may encounter some snakes (or ladders) – large events such as Covid19 – that may upset our course.

IPCC AR6 wg2 report. The image, from the Summary for Policymakers report, shows various paths from the present situation, leading to either low global warming, low poverty, ecosystem health, and well-being, or to high global warming, high poverty, ecosystem degradation and inequity and injustice.

Energy generation diversification, including with renewable energy resources and generation that can be decentralised depending on context (e.g., wind, solar, small scale hydroelectric) and demand side management (e.g., storage, and energy efficiency improvements) can reduce vulnerabilities to climate change, especially in rural populations (high confidence).

Safeguarding biodiversity and ecosystems is fundamental to climate resilient development, in light of the threats climate change poses to them and their roles in adaptation and mitigation (very high confidence). Recent analyses, drawing on a range of lines of evidence, suggest that maintaining the resilience of biodiversity and ecosystem services at a global scale depends on effective and equitable conservation of approximately 30% to 50% of Earth’s land, freshwater and ocean areas, including currently near-natural ecosystems (high confidence).

Last word:

Any further delay in concerted anticipatory global action on adaptation and mitigation will miss a brief and rapidly closing window of opportunity to secure a liveable and sustainable future for all. (very high confidence)

Key points from the IPCC AR6 wg2 Technical Summary

So here are a few quotes from the IPCC AR6 wg2 Technical Summary to add to the picture above. It’s not a very comfortable document to read as each page is stamped, in huge font, with ACCEPTED VERSION SUBJECT TO FINAL EDITS. Do they actually want people to read this?! Reminds me of the scientists attempting to deliver their message in Don’t Look Up (which is actually very good and well worth watching, BTW).

IPCC AR6 wg2 report summary. 
The image shows Leonardo DiCaprio playing the role of a scientist in the film, Don't Look Up.

Anyway, here are some highlights:

Climate change will increase the number of deaths and the global burden of non-communicable and infectious diseases (high confidence). Over 9 million climate-related deaths per year are projected by the end of the century, under a high emissions scenario.

That’s about three times the death rate from Covid-19, which has killed less than 6 million people over two years. I think it’s also an underestimate since it’s not factoring in deaths from unexpected weather events, etc. This would have been a useful number to include in the Summary for Policymakers, but it was left out.

Climate change is already stressing food and forestry systems, with negative consequences for livelihoods, food security and nutrition of hundreds of millions of people, especially in low and mid-latitudes (high confidence). The global food system is failing to address food insecurity and malnutrition in an environmentally sustainable way.

Climate change is projected to put 8 million to 80 million people at risk of hunger in mid-century, concentrated in Sub-Saharan Africa, South Asia and Central America (high confidence).

Extinction of species is an irreversible impact of climate change, the risk of which increases steeply with rises in global temperature (high confidence). Even the lowest estimates of species’ extinctions (9% lost) are 1000x natural background rates (medium confidence).

Conservation and restoration will alone be insufficient to protect coral reefs beyond 2030 (high confidence) and to protect mangroves beyond the 2040s (high confidence). Deep cuts in emissions will be necessary to minimize irreversible loss and damage (high confidence).

Cross-sectoral solutions include improved air quality through renewable energy sources (very high confidence), active transport (e.g., walking and cycling) (high confidence), and sustainable food systems that lead to healthier diets (high confidence).

Increasing social and gender equity is an integral part of the technological and social transitions and transformation toward climate resilient development. They often require rights-based approaches to protect the livelihoods, priorities and survival of marginalised groups including Indigenous peoples, women, ethnic minorities and children. (high confidence)

Climate smart agriculture technologies strengthening synergies among productivity and mitigation is growing as an important adaptation strategy (high confidence).

Tropical rainforests and global peatlands are particularly important carbon stores but are highly threatened by human disturbance, land conversion and fire

Prevailing governance efforts have not closed the adaptation gap (very high confidence).

I’ll summarize the IPCC AR6 wg3 report when it comes out in April. It’s probably going to be the most important report as it will focus on solutions.

Let’s hope these next reports are a bit more compelling and easier to read. Please get rid of the gigantic ACCEPTED VERSION SUBJECT TO FINAL EDITS that’s plastered across each page of the Technical Summary and main report documents  – unless your goal is that people don’t bother reading them. Use more images and use better formatting and emphasis to make the text more readable. Please put more of the concrete information and suggestions into the Summary for Policymakers and make it compelling. No pressure, IPCC scientists and report writers – it’s not like all life on planet Earth depends on it. Oh, wait…

5 thoughts on “IPCC AR6 wg2 report summary

Leave a Reply