Earlier this year we reported on new evidence that global greening due to rising CO2 levels is not only continuing but accelerating. Which is great news, if you’re the sort who thinks a green planet is a good thing. As in you like crops, trees, flowers and that stuff. Looking over what we’ve had to say on this topic over the years (including our ongoing series summarizing the CO2Science.org archive of plant growth studies) we realize we’ve drawn a lot of attention to it. And no wonder, global greening due to rising CO2 is a key part of the climate change story: CO2 is plant food and it stands to reason that with more of it in the air plants will grow better, including the crops on which we and our animal friends depend, and that’s an unmistakable benefit. But we’ve noticed alarmists don’t talk about greening, which got us wondering if they simply don’t know about it. Except they follow the science, don’t they? And surely it’s mentioned by the IPCC isn’t it? Well, not exactly. This week we will start a tour through the recent reports of the IPCC to find out what they tell their readers about the greening of our planet. We begin with the Summaries for Policymakers or “SPMs” of the 6th Assessment Report, since the SPMs are the only parts most journalists and policymakers ever read even if they are, in a very major way, not just summaries for but also by policymakers, bypassing the scientists to tell themselves what they want to hear. And guess what they never mention.
Yup, they say precisely nothing about CO2-induced global greening.
There are three volumes in the Sixth Assessment Report, one from each of the Working Groups, and each one has an SPM. Working Group I reviews the physical sciences, covering all the topics they think climate policymakers need to know about. And their SPM is the focus of enormous worldwide media coverage, unlike the substantive scientific papers which are long, technical and hard. So the IPCC spends a lot of time going over every line of it to make sure it includes everything they want to say and leaves out everything they don’t want to say.
And here is the result of our search:
That’s right, nada, zilch. (We would say “bupkis” but it means “beans” and as we note below, beans like CO2.) Same with the SPM of Working Group III which advises policymakers and the media on climate mitigation. Not a single mention of global greening, though it is both a source and an example of mitigation.
Working Group II is concerned with “impacts” of climate change so maybe that’s where the action is since massively more plant life sure looks like an impact. Nope. We do get one hit, but it’s not a reference to global greening, instead it’s a reference to local urban greening (p. 24, emphasis added):
“Effective Ecosystem-based Adaptation reduces a range of climate change risks to people, biodiversity and ecosystem services with multiple co-benefits (high confidence). Ecosystem-based Adaptation is vulnerable to climate change impacts, with effectiveness declining with increasing global warming (high confidence). Urban greening using trees and other vegetation can provide local cooling (very high confidence). Natural river systems, wetlands and upstream forest ecosystems reduce flood risk by storing water and slowing water flow, in most circumstances (high confidence).”
This just in: IPCC discovers that it’s cooler in the shade. But not that there might be more shade in the future as trees grow taller and leafier with all that lovely CO2 available.
Incidentally the same results apply if we search the 5th Assessment Report: no mention in the SPMs for Working Groups I and III, and only a brief mention in Working Group II having to do with urban greening as a way of cooling surfaces.
So if you are talking to someone about climate change and they have dutifully read all the SPMs of all the Working Groups of the past two IPCC Assessment Reports, don’t expect them to know anything about global greening. But we can also ask whether the IPCC has buried the good news somewhere deep in the reports. Next week we’ll begin a deep dive into the full chapters of the 6th Assessment Report to find out.
Years ago, when all of this horse manure started, I asked about these ecological responses to additional CO2 and warmth in the atmosphere. Every time I asked that question, I got crickets as a reply which told me that this was ALWAYS a political operation!
We never seem to hear why increased CO2 improves the greening..... here's the simplified reason. Rubisco, the enzyme at the heart of photosynthesis (and the most abundant protein on the planet) evolved before there was significant oxygen in the atmosphere around 3.8 billion years ago. The subsequent photosynthesis lead to extinctions from the Great Oxidation Event.
The active site in Rubisco looks for a molecule with an oxygen on each end i.e. CO2. Most enzymes work at speeds of 1,000 to 10,000 cycles per second. Rubisco manages a tardy 1-10/second. The why is the interesting bit.... there is now another new molecule in the atmosphere that also has an oxygen on each end.... Oxygen or O2. And every time one of these connects to a Rubisco active site, the enzyme has to do a reset.... until it gets a CO2 molecule and work its wonders. In the atmosphere there are 420ppm of CO2 and 210,000 ppm of oxygen, 500 times that of CO2. So Rubisco has to process and reset from 500 Oxygen molecules before it chances on a CO2. You can now see why Rubisco is such a poor performing enzyme. If we double the amount of CO2 in the atmosphere, we double Rubisco's chances of a CO2 selection and thus the rate of photosynthesis, and global greening. The increase from around 280ppm of CO2 to today's 420ppm has lead to a statistical 50% improvement in Rubisco's performance. As we move towards a peak of 10 billion people on the planet, this extra photosynthetic capacity will help feed the extra mouths without taking more land from nature, thus saving the planet's biodiversity.
I'll be surprised if further deep reading of these said Reports reveals anything positive about our greening Earth.That would be contrary to the alarmist agenda of the Climateers.Climate change is all bad,and all caused by humans,you see.