Reading the new IPCC climate crisis report: part 1

Today we’ll start our reading of the new IPCC climate report.

In this post you’ll find a summary of the “Summary for Policymakers,” along with questions, observations, and some resources.  We’re following the online reading plan laid out here.

1: SUMMING UP 

The Summary begins by asserting a finding: that human activities have warmed the world.  The document breaks this down by parts of the world (sea, land, different atmospheric layers) and by degrees of certainty, along with room for some unevenness of cause and effect.  Consequences include increased rain overall, decreased ice and snow mass, shifting some storm tracks towards the north and south poles, sea level rise, extension of growing seasons in northern hemispheric temperate regions, “climate zones have shifted poleward in both hemispheres,” and ocean acidification.  How much have we heated the world?  “The likely range of total human-caused global surface temperature increase from 1850–1900 to 2010–201911 is 0.8°C to 1.3°C, with a best estimate of 1.07°C.”

The main human-created sources of climate change start with carbon dioxide, followed by methane. Several sources actually reduce temperatures:

IPCC 2021 causes of global temp changes-B

This human intervention into the climate represents a clear break from thousands of years of history:

IPCC 2021 surface temp changes 1850-1900

The Summary goes on to describe extreme hot weather events rising, including heat waves, great rainfall in monsoons, more rain in general, droughts, and tropical cyclones.  Compound hot weather events are also more likely – i.e., when two or more occur at the same time and overlap. At the same time, extreme cold weather events are gradually decreasing.  The report finds humanity playing some role in making this transformation occur.

IPCC 2021 rain and drought maps

Where excessive rain and more droughts are most likely to occur, seen through a schematic map.

Oceans play by far the largest role in soaking up increased temperatures: “Ocean warming accounted for 91% of the heating in the climate system, with land warming, ice loss and atmospheric warming accounting for about 5%, 3% and 1%, respectively…”  However, if global temperature rise hits higher ranges, the atmosphere will pick up more of the heat.

The 2021 Summary finds that equilibrium climate sensitivity is around 3°C.   ECS is an estimate of how much the world will ultimately warm, once the planet reaches a new equilibrium with incoming solar radiation.

Based on multiple lines of evidence, the very likely range of equilibrium climate sensitivity is between 2°C (high confidence) and 5°C (medium confidence). The AR6 assessed best estimate is 3°C with a likely range of 2.5°C to 4°C (high confidence)…

The Summary continues by offering five different scenarios for how much greenhouse gas output humanity might produce and how that can impact global temperatures over the rest of this century.  Each is named for a different “Shared Socio-economic Pathway,” or SSP:

IPCC 2021 5 scenarios

The report offers several wild cards or unusual events which may have an outsized impact.  One possibility is the chance of a major volcanic eruption, perhaps somewhat greater than those of Mount Pinatubo (1991) or Novarupta (1912). This form of nonhuman geoengineering might cool temperatures by ejected huge amounts of particles into the atmosphere, which then circulate globally:

C.1.4 Based on paleoclimate and historical evidence, it is likely that at least one large explosive volcanic eruption would occur during the 21st century. Such an eruption would reduce global surface temperature and precipitation, especially over land, for one to three years, alter the global monsoon circulation, modify extreme precipitation and change many CIDs (medium confidence). If such an eruption occurs, this would therefore temporarily and partially mask human-caused climate change.

In the opposite direction is the low-probability chance of a suddenly quickened ice sheet collapse. That’s for the most extreme scenario, SSP5-8.5, and would “result… from ice sheet instability processes characterized by deep uncertainty and in some cases involving tipping points…”  This could surge ocean levels beyond anything else discussed:

IPCC 2021 extreme scenario low-probability event

Beyond the year 2100, the changes described so far will last for centuries.  Higher levels of ocean acidification, higher ocean temperatures, smaller icepacks, reduced permafrost, and sea level rise will persist for a long time.  In particular, on oceans:

sea level is committed to rise for centuries to millennia due to continuing deep ocean warming and ice sheet melt, and will remain elevated for thousands of years (high confidence). Over the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming is limited to 1.5°C, 2 to 6 m if limited to 2°C and 19 to 22 m with 5°C of warming, and it will continue to rise over subsequent millennia (low confidence).

What is to be done?  The IPCC summary is quite clear: a mix of zeroing out carbon emissions along with drawing down and storing already lofted CO2.

Achieving global net zero CO2 emissions is a requirement for stabilizing CO2-induced global surface temperature increase, with anthropogenic CO2 emissions balanced by anthropogenic removals of CO2.

Cutting down methane and other GHG is good, too.

2: QUESTIONS

Which scenario is most likely to occur, in your view?

How would zeroing out carbon emissions and cutting back emissions impact your life and your academic work?

How can we best communicate the Summary’s findings to a broader audience?

Do the IPCC’s projections look dangerous enough to justify the risks of geoengineering?

What should higher education do in the wake of this new report?

3: REFLECTIONS

Overall, the new IPCC report confirms much of what I already researched about anthropogenic climate change. That doesn’t take away from its value, I think. Instead, continuities with other research show the science crystallizing.  That said, the ECS is lower than it was in earlier reports. There is more confidence in findings.

The scenarios are bare bones, just consisting of changed metrics along a similar line of datapoints.  But I think we can build on them.

I haven’t seen many academic responses so far.  By that I mean academics reflecting on what this means for higher education.

Writing all of the preceding took some self-control, as emotions of dread continued to hit me, even after being immersed in the subject for years.

4: MORE INFORMATION

From the IPCC, a press release. A Trello board. An interactive atlas.

Michael Mann, one of the world’s leading climatologists, offers his reflections.

Introduction at The Conversation by Robert Kopp,  Professor, Department of Earth & Planetary Sciences, and Director, Rutgers Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University.

The New York Times has a good introduction with some reactions.

Morning Consult compared the report’s urgency to the American public’s apathy.

…and now over to you.  What do you think of the summary?  Is there anything we should focus on?  Want to try one of the questions?

(thanks to Vanessa Vaile for linkage)

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12 Responses to Reading the new IPCC climate crisis report: part 1

  1. Vanessa Vaile says:

    Glad to see our IPCC reading is back on track. I saved my first OneTab bundle of links (23) for the reading August 12th and am closing in on save the second (16).

    Caveats: I’m not collecting from an exclusively higher education perspective. That said, I have been keeping my out for the higher ed angle but am more interested higher ed contribution to solutions. Climate change cuts across so many other issues, many that also intersect with higher ed. For me, the education part is more about explaining to the climate indifferent and resistant to cultivate awareness and engagement.

  2. Glen McGhee says:

    Another consideration is volcanic activity — eruptions send mega-tons of ash and dust into the atmosphere, reducing surface temperatures. Be careful what you wish for.

    https://eos.org/science-updates/anticipating-climate-impacts-of-major-volcanic-eruptions

  3. Dahn Shaulis says:

    There are two alternatives to digesting the IPCC material and assuming this information matters. (1) You could go the George Carlin ultra-cynical route, or (2) the Liberty University Jesse Helms School of Government ultra-paranoid route. Both are worth discussing in Universities on Fire.

    https://www.youtube.com/watch?v=7W33HRc1A6c

    https://digitalcommons.liberty.edu/cgi/viewcontent.cgi?article=1907&context=honors

  4. Phillip Long says:

    Useful resource when reading this report is the EPA Glossary of Climate Change Terms.
    The terms can sometimes be daunting. This glossary helps.

    https://19january2017snapshot.epa.gov/climatechange/glossary-climate-change-terms_.html

  5. Phillip Long says:

    The IPCC Summary is a direct, hard-hitting updated collection of all that is scientifically known with expressed degrees of certainty. I had to take multiple breaks in reading it to get through it. Not because of the difficulty in understanding the science. That was clear enough. It was the consequences are so profound, so devastating, and the public reaction apathetic that it reinforced the sense of certainty that this is the future and humans will dither while the planet burns.

    One caveat to note up front before getting to your questions. Alternative assumptions may result in similar emissions and climate responses, __but the socio-economic assumptions and the feasibility or likelihood of individual scenarios is not part of the
    assessment__… (pg.15 of the SFP). In particular the socio-economic assessments I think will have major consequences for nations ability to sustain climate remediation responses over the duration that is necessary to have any meaningful impact.

    To the questions.
    1) Which scenario is most likely to occur, in your view? – The intermediate scenario (SSP2-4.5) is pragmatically the most likely given the unwillingness people express to commit to the disruptions in lifestyle and the costs of significant CO2 reduction. This will give a 2.1 to 3.5 deg C avg temperature rise from 2081-2100. (pg. 17). I actually am torn between this scenario and SSP3-7.0 given my general pessimism that humans can sustain for centuries, and it will take sustaining remediation investments at high levels for CENTURIES, the commitment needed to bring arrest those things that aren’t already set for millennia.

    2) How would zeroing out carbon emissions and cutting back emissions impact your life and your academic work? – It would marginally improve the few remaining decades that I have on this planet. Most importantly it would give me some hope that my kids and grand kids have a potential to make a positive difference. I’m already refocusing my efforts to look at how we can create solar energy cooperatives around the country. But my individual efforts here are a minimal in the grand scheme of things. I don’t see universities stepping up to the plate with the force and commitment needed.

    3) How can we best communicate the Summary’s findings to a broader audience? – I suspect a commitment to translate these academic findings into graphic novels/comics/and TV series plot points (from sitcoms to dramas)/ and digital games plus social media sites ‘climate tok’ are esssential. Influencers need to be cultivated into the movement. This science is clear, both in what it is predicting and in the public dismissal of it.

    4) Do the IPCC’s projections look dangerous enough to justify the risks of geoengineering? – No. This is hubris. It has take decades of concerted effort from tens of thousands of scientists around the world to just get the picture in place we have today. But there is so much we don’t understand about the large scale systems at play to think we could have confidence in planetary geo-engineering to pursue that route. It’s folly.

    5) What should higher education do in the wake of this new report? The only sane thing to do is redesign the curricula of every discipline to meaningful address this planetary crisis. I don’t mean redirect the focus of every discipline to simply and only address climate change. I do mean including substantive attention toward how every discipline can use it’s framework and mindsets of thinking to creatively address this extinction event with the context of failing to do that the rest of the discispline is moot. Will they? Not likely.

    • Glen McGhee says:

      This weeks Barron’s has a letter to the Editor complaining about IPCC report, apparently on technical grounds. FYI.

      • Phillip Long says:

        Glen: I looked for the post on Barron’s but couldn’t find anything in this week’s edition. Do you have a link for it by chance?

        • Glen McGhee says:

          Sept 3 2021

          To the Editor:
          As a scientist who spent a career developing clean-energy technologies, I would tell you there is no “climate crisis.” Polman cites the authority of the United Nations Intergovernmental Panel on Climate Change, or IPCC, as the basis for his thesis. If he had based his comments on the actual detailed report of the IPCC Working Group I, the assessment by participating scientists, instead of the U.N. Summary for policy makers and the media written by political appointees (not scientists), he would have come away with a much less onerous view of the “crisis” caused by man’s use of fossil fuels.
          Edward Bohn, Seahurst, Wash.

          • Vanessa Vaile says:

            Edward Bohn’s energy credentials, nuclear and oil/gas extraction, suggest bias.

          • Glen McGhee says:

            >>Edward Bohn’s energy credentials, nuclear and oil/gas extraction, suggest bias.

            Yes, that is probably true — but he refers to “IPCC Working Group I” documents, and states they are more detailed and nuanced than the IPCC given to the press, etc. Do we have access to the documents which he refers to? Thanks!

  6. Glen McGhee says:

    >>Edward Bohn’s energy credentials, nuclear and oil/gas extraction, suggest bias.

    Yes, that is probably true — but he refers to “IPCC Working Group I” documents, and states they are more detailed and nuanced than the IPCC given to the press, etc. Do we have access to the documents which he refers to? Thanks!

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