Reading the IPCC Sixth Assessment Report: Another Hot Take

I just read the latest Intergovernmental Panel on Climate Change report, released Monday, and I’m still trying to unclench my jaw. As Tim Van Deelen wrote on this blog earlier this week, the findings were not new or surprising for those who have been attentive to climate issues. Which I have been, keenly, for about the last five years. Nevertheless, the report is sobering, and has appropriately been touted as “code red for humanity.”

Actually, I should be clear that I did not read all 4000 pages of technical details included with the full report, whose official title is Climate Change 2021: the Physical Science Basis. I carefully read the 42-page Summary for Policy Makers and nosed around on the very fine, nicely navigable website. Tim provided, in his post, an authoritative reminder of how science works and what scientific reliability means. I’ll follow up here with some highlights from the report and some real-life implications, at least as I see it.  

It’s real and it’s us

“It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred” (p. SPM-5).

That’s the summary of section A.1, the opening salvo. It’s a big deal for scientists to use the word “unequivocal.” What they are trying to communicate is this: insofar as human beings are capable of knowing anything, we do know this.

Mostly this report confirms what we learned in previous reports and refines the details. This is possible because the science is continually getting more precise. That means we have better data about the past, more and better observations about the present, and better modeling techniques to estimate future effects. We also continue to refine the “science of attribution”—that is, figuring out how much of what we observe is just baseline and how much is a result of human activities, including greenhouse gas emissions and agricultural practices such as deforestation. As Tim noted, science is iterative and cumulative.

Let’s say a few more words about epistemology a minute. The way these IPCC reports work is rather fascinating. The IPCC was formed in 1988 by the United Nations, and 195 member governments participate, including the US and Canada. We are now on the sixth “assessment cycle,” which includes all the reports released from 2015-2023. Eight reports are planned, including this one, from three working groups. This report on the physical science will be followed by two more, on impacts/adaptation, and then on mitigation. For this report, 234 scientists from 66 countries volunteered their time to read and compile and summarize all the relevant scientific literature. There are 14,000 references and 78,007 expert and government review comments incorporated. All 195 member governments had to sign off on the report.

So as I say, as far as creating human knowledge goes, this is the very, very best we can do.

It’s bad

Here is the US, it has been a rough summer. Heat waves in the Pacific Northwest and fires all over the West, for example, have been devastating. But we are seeing extreme weather events increasing in frequency and/or intensity all over the world: droughts, floods, fires, heat waves, tropical storms. You know this from the news. And if you do not feel personally affected, well, good for you. But in that case, you are likely sheltered from effects by your geographic luck and your wealth, which creates resilience. Other people around the world are not so lucky. And it will get worse.

The “global weirding” we are experiencing now is the result of 410ppm CO₂ in the atmosphere and 1.1° C of warming as compared to preindustrial levels (1850-1900 is the baseline). This is unequivocally human driven. Yes, they’ve accounted for “natural drivers” of warming. There’s a nice chart on p. SPM-7. These are not just normal cycles: “In 2019, atmospheric CO₂ concentrations were higher than at any time in at least 2 million years (high confidence), and concentrations of CH₄ and N₂O were higher than at any time in at least 800,000 years (very high confidence)” (SPM-9). Moreover, the changes are accelerating: “Global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2000 years (high confidence)” (SPM-9).

Note that, in carefully scientific fashion, nearly every sentence in these reports is followed by a note indicating, on a defined scale, how certain the authors are about each fact.

Things will get worse

One of the most important takeaways from this report is that, no matter what we do, things will get worse for a while.

The report offers five modeling scenarios. These scenarios range from we reach net zero greenhouse gas emissions by 2050 to we carry on merrily just as we are to we produce even more greenhouse gases and basically destroy the earth. Please note: those are my own summary phrases.

Here’s the scary part: even if we pull ourselves together and reach net zero emissions by 2050, the average global temperature will still rise 1.5+ °C over pre-industrial levels before it stabilizes and maybe even goes back down a little. Remember, 1.5 °C is another half-degree from where we are now. This will mean that all those extreme weather events we are now seeing will get worse. No matter what we do, things will get worse.

There’s a nifty chart on p. SPM-23 showing estimates of how much more frequent various kinds of 10-year and 50-year events will be under the various scenarios. For instance, right now, 10-year heat waves (the kind that used to occur only every 10 years) happen 2.8 times more often. At 1.5° C increase, they will happen 4.1 times more often.

As the report soberly states, “There will be an increasing occurrence of some extreme events unprecedented in the observational record with additional global warming, even at 1.5 °C of global warming” (SPM-19).

Section B, on ocean effects, was the grimmest section for me. We have screwed up the ocean and the effects are baked in—wait for it—for thousands of years. Even if we do everything “right” and do it this very minute, ocean temperature rise, ocean acidification, and sea level rise cannot be undone. We know this with a “high degree of certainty.” The estimate is that if we manage the “very low” scenario, we will still experience sea level rise of .5 m by 2100 and that will keep going, reaching 2-3 m over the next 2000 years. (Ocean rise is caused by glacier melt and by “thermal expansion”—warmer water takes up more space.)

Suffice to say, the “very low” scenario is the one we want. The other ones—well, look at those charts. The other ones are just unimaginable. Stay the same, and we’ll be at 2-3.5 °C over preindustrial levels by end of century. The last time it was that hot was 3 million years ago.

So let’s summarize. Even if we act right now, we have screwed up the ocean. And even if we act right now, the temperature will not stabilize for 20-30 more years. For the very low scenario, it is “more likely than not” that we could get global surface temperature to decline back to below 1.5 °C toward the end of the 21^st century, “with a temporary overshoot of no more than 0.1 °C above 1.5 °C global warming” (SPM-18).

That’s probably my lifetime. So I will never again see the world as it was the year I was born. In fact, neither will my children or (potential) grandchildren, and who knows after that? The earth is a “tough, new planet,” as Bill McKibben says. Our job now is to keep it from getter even tougher, for humans and for all forms of life.

So what do we do?

Well, the good news here is that we know what we have to do: cut carbon emissions in half by 2030 and reach net zero by 2050. According to IPCC Working Group I Co-Chair Panmao Zhai, “Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO₂ emissions.”

The bad news is: we have to work together to do it. Can we manage that?

I worry about our capacity to care enough, about each other and this earth, to manage the changes we need. Many Americans can’t even care enough about knowledge or each other to wear a stupid mask, for crying out loud.

I wonder whether people of faith, Christians specifically, can be relied on to have the capacities we ought to have: love for neighbor; willingness to sacrifice; love for God’s earth; skills for lamenting, repenting, forgiving, praising; humility; hope. Do we have those capacities? Many days, my cynicism wins out and I doubt it.

However, God is not limited by the fears and failures and faults of Christians. It’s marvelous that scientists across the world are working collaboratively on this mighty project. It’s wonderful to see all kinds of people—not just science professionals, but artists and teenagers and government officials and business leaders and community leaders and farmers and ranchers—finding their way into the “Great Work,” as Thomas Berry called it, of transition to new ways of living on the earth. The Spirit of God is working in the world across all borders of nation, religion, gender, wealth, and power.

I’ve been invested in this work just long enough myself to get past the horror and sorrow (most days) and move on to grim determination. I also feel: excitement. I want to live in a net-zero world. I want to live in a world where we use clean energy, restore ruined ecosystems, and farm regeneratively. I want to live in a world where we create circular economies and zero-waste cities. I want to live in a world where we have corrected or at least greatly mitigated environmental injustices. Change is hard and scary, but it’s also full of possibility.

I am fully convinced that God is calling us all—people of all faiths and no faith—to heal this earth. Let’s do it.

What can I do?

Get educated. Pay attention. Most important: don’t just be one person. Join up with others. Find some way into this “great work” that you care about—maybe it’s advocacy or regenerative agriculture or art or helping little children love birds—and find others who do it, too. Talk about it. Press your church to get involved. Do whatever you’re good at, with your whole heart.

Practically speaking, the top priority right now is transitioning global energy systems off fossil fuels and onto renewables. It can be done, but it won’t be easy. Whatever you can do to push for that, do it. Ron and I have solar panels on our roof and an electric car—we’ve become early adopters because we have the means and we want to encourage others. Meanwhile, I’ve been nagging my representatives to do everything they can to adjust government incentives to promote energy transition. I’ve been listening to podcasts that help me understand what that means for my region: the devil, as always, is in the details, and the details are both global and local. Likely you have more power over the local.

As for the various personal pieties that always get trotted out—like recycling and plastic-use reduction and eating less meat—these are all great and important. But don’t imagine the whole world depends on whether or not you have a burger. No one can bear all the weight. Each of us must do what we can as a spiritual practice and to help encourage others.

There’s so much more to say. I hope that here at The Reformed Journal, we will keep talking about this together. And see below for some more links and suggestions.  

Check out this week’s Reformed Journal Podcast for an interview with Tim Van Deelen.

Here’s a piece by Katharine Hayhoe in TIME about the IPCC report.

Here’s a place to start in learning about climate change.

Here’s another place.

Here’s the website for COP26 in Glasgow this November, the big UN climate change conference.

This, and this, and this are some excellent podcasts that I listen to. There are more.