It's disappointing that an editor at Discover magazine would write this:"If you’ve been following climate news, you’ve probably heard about an approaching “tipping point” toward climate change — the point of no return after enough small changes brought us to certain disaster."The truth is, there is no such tipping point!
Climate change doesn't work that way. It's incremental -- some change in temperature for a change in emitted CO2 (about 2/3°F per trillion short tons of CO2 emitted, in fact).
(1 short ton = dumb English unit = 2,000 lbs = 907 kg (at Earth's surface.))
In smart units, that's 1.5°C/TtC (trillion tonnes carbon emitted). From Matthews+ Nature 2009.
This is a rather amazing equation, because it doesn't need to know how much CO2 goes into the ocean vs soil vs stays in the atmosphere. It doesn't explicitly need to know equilibrium climate sensitivity (the equilibrium temperature change after atmo CO2 doubles). These things cancel out (see the Matthews+ paper.) AFAIK, this is the relationship planners and policy makers use to determine how the world will stay below 1.5°C or 2.0°C or whatever.
Back to the quote. There may be tipping points in the future, but it is not nearly as clear cut as the author writes. No one knows. They are very uncertain. (No, that's not a good thing.) In fact, I've already heard (good) scientists say that Arctic sea ice has probably already passed a tipping point in its melting -- that it's not going to recover.
But there is no hard deadline by which we must solve climate change. It's not 12 years or 2030 or, now I'm seeing, 11.75 years. That's just not how climate change works. The sooner we cut emissions, the better. The later the worse. Partial cuts are better than none.
I (mostly) blame AOC.
You probably did it right, but I mainly blame your colleagues. We had weeks of media headlines that the UN had said that only had 12 years to act.
ReplyDeleteI tried to fight it with my little blog, but there is no fighting the deluge coming out of the mass media and in this case also many quality newspapers. Even partisan media like Fox News wrote this.
Another curiosity of this deluge was that they typically talked about the UN, rather than the IPCC, which are really different animals.
That politicians trust the overwhelming consensus of quality newspapers is normal.
All good points, Victor. Thanks.
ReplyDeleteDavid, it’s a slow news day, so I thought I’d address what you wrote. I agree with your general statement that the news media and some individuals are writing misleading statements about the whole climate system reaching a tipping point. Usually I see this with respect to runaway warming because of the so-called ‘methane bomb’. There is no runaway warming. However, that is not to say that there hasn’t been sufficient scientific attention paid to so-called ‘tipping elements’ in which portions of the climate system are in an unstable equilibrium. See for example, this paper by Rahmstorff and co-workers: https://www.nature.com/articles/nclimate3013
ReplyDelete“I (mostly) blame AOC”
I think this is unfair. The origin of a lot of grief directed towards AOC came from an interview she had with Ta-Nahesi Coates in which she said the following: “Millennials and people, you know, Gen Z and all these folks that come after us are looking up and we’re like: The world is going to end in 12 years if we don’t address climate change and your biggest issue is how are we gonna pay for it?”
Is this hyperbole? Of course it is. Who among us hasn’t made ridiculous statements when speaking off-the-cuff? But she isn’t saying the world is going to end in 12 years, but that millennials and such are feeling that way.
Here’s what the IPCC actually said, “In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40–60% interquartile range), reaching net zero around 2050 (2045–2055 interquartile range)”. It would not be hyperbole to interpret this statement as saying that in 12 years’ time we need to take massive transformative action on how we use energy.
AOC has clearly made mistakes, such as how her staff originally rolled out the GND. Lately, I’ve seen more careful statements from AOC that we need to cut our emissions in half by 2030. In contrast, there are only a few right-wing nutcases out there who acknowledge their mistakes. At least AOC has the courage to go to Kentucky and talk to coal miners and what the GND might mean to them. Unlike a certain cowardly Republican congressman who ran away from his invite:
https://www.businessinsider.com/alexandria-ocasio-cortez-kentucky-republican-andy-barr-coal-mines-2019-4
To follow up briefly on this topic, read Myles Allen excellent article "Why protesters should be wary of ‘12 years to climate breakdown’ rhetoric"
ReplyDeletehttps://theconversation.com/why-protesters-should-be-wary-of-12-years-to-climate-breakdown-rhetoric-115489?utm_source=twitter&utm_medium=twitterbutton
I finally watched the whole interview of Ta-Nehesi Coats' interview with AOC. You can find it here: https://www.youtube.com/watch?time_continue=3280&v=q3-QvoIfpxc
The interview is roughly from 16 to 1:05 and her very short take on climate comes at 53:25.
To put this in some context, this interview was held on MLK day at the Riverside Church where a year before his death, MLK gave a profound speech against the war in Vietnam and for racial justice. The conversation with AOC was in that spirit. She talks about what kind of society do we want to have, discusses her proposal for a 70% marginal tax rate, that people in Alabama are still struggling with ringworm, the huge homeless problem in New York.
It is in her discussion about why the engages with people on twitter that her remark about climate comes in. She talks about what engages people in her generation and the point she makes is really in the last part of the quote I mentioned above " ... AND YOUR BIGGEST ISSUE IS HOW ARE WE GONNA PAY FOR IT". Economic disparity is the major theme of her talk, as it was with MLK. AOC brings in wealth inequality and the criminal justice system ALONG with climate as topics that her generation feel that "fierce urgency on now", again, linking it back to MLK. Give it a listen is my suggestion.
One more thing, Pulitzer prize winner Joseph Ellis is one of my favorite writers on the American Revolution. Read his take on the GND, "The Green New Deal isn't socialism. It's what the Founding Fathers wanted"
https://www.cnn.com/2019/04/18/opinions/green-new-deal-not-socialism-ellis/index.html (and watch the short clip of AOC defending the GND)
Here's AOC with a more scripted "12 years" rhetoric:
ReplyDelete"And in the next year, when I as elected to congress, the worlds leading climate scientists declared another emergency. They told us that we had 12 years left to cut our emissions in half or hundreds of millions of people would be more likely to face food and water shortages, poverty, and death. 12 years to change everything"
That may be technically true. I'm not sure. But The 12 year rhetoric is not helpful because year 12 will look much the same as the previous year. Changes are incremental. We don't walk off a cliff at 1.5C.
Here's how the report she's referencing describes climate impacts of 1.5 and beyond (chapter 1.3.2).
"The impacts of 1.5°C global warming will vary in both space and time (Ebi et al., 2016). For many regions, an increase in global mean temperature by 1.5°C or 2°C implies substantial increases in the occurrence and/or intensity of some extreme events (Fischer and Knutti, 2015; Karmalkar and Bradley, 2017; King et al., 2017; hevuturi et al., 2018), resulting in different impacts (see Chapter 3). By comparing impacts at 1.5°C versus those at 2°C, this report discusses the ‘avoided impacts’ by maintaining global temperature increase at or below 1.5°C as compared to 2°C, noting that these also depend on the pathway taken to 1.5°C (see Section 1.2.3 and Cross-Chapter Box 8 in Chapter 3 on 1.5°C warmer worlds). Many impacts take time to observe, and because of the warming trend, impacts over the past 20 years were associated with a level of humaninduced warming that was, on average, 0.1°C–0.23°C colder than its present level, based on the AR5 estimate of the warming trend over this period (Section 1.2.1 and Kirtman et al., 2013). Attribution studies (e.g., van Oldenborgh et al., 2017) can address this bias, but informal estimates of ‘recent impact experience’ in a rapidly warming world necessarily understate the temperature-related impacts of the current level of warming..."
https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SR15_Chapter1_Low_Res.pdf
Layzej, I think it is a fundamental mistake for a scientist to pick a number like 12 years, as Myles Allen nicely explains. However, if a politician wants to articulate a particular policy, then it's important to have a timeline. That's what AOC is doing.
ReplyDeleteOne can argue, as Jesse Jenkins does, that the economic costs of setting the goal at 12 years is way too high. He'd rather stretch that timeline out to 2050. However, I see the GND as a starting point in the negotiating process. What I think AOC adds to the conversation is that she wants to couple fighting climate change with making sure that the world is a more just place for all people. I understand that some may think this approach is too broad. I don't.
"I think it is a fundamental mistake for a scientist to pick a number like 12 years, as Myles Allen nicely explains. However, if a politician wants to articulate a particular policy, then it's important to have a timeline."
ReplyDeleteFair enough, but she starts by attributing that timeline to the worlds leading climate scientists: "the worlds leading climate scientists declared another emergency. They told us that we had 12 years left..."
That's misrepresenting the scientists. I understand the utility of "12 years..." but it will backfire on the scientists who never said that in the first place.
The quote says that "we have 12 years left to cut our emissions in half...". That's a policy statement. My problem with the statement is more subtle. Climate scientists like Hansen have used the term "emergency", David Archer says "crisis", Mann says "mobilization" is needed. The IPCC report itself uses terms like "rapid and far-reaching
ReplyDeletetransitions in energy","unprecedented" and "far-reaching". So, while scientists have used terms similar to emergency in general, did climate scientists declare an emergency in this report? No, they didn't.