Greening the planet and slouching towards Paris?

Eiffel tower, Paris. France

Reposted from Dr. Judith Curry’s Climate Etc.

Posted on May 14, 2020 by curryja |

by Patrick J. Michaels

A new paper finds higher than expected CO2 fertilization inferred from leaf to global observations.  The paper predicts that the Earth is going to gain nearly three times as much green matter as was predicted by the IPCC AR5.

Earlier this month, I posted a short piece about an explosive paper on planetary greening that appeared in the journal Global Change Biology. I’ve since mused that it deserves a considerably longer, more contextual post.

The innocuously titled paper, “Higher than expected CO2 fertilization inferred from leaf to global observations”, by Vanessa Haverd (of Australia’s CSIRO) and eight coauthors uses a biophysical model and observed climate to back-calculate global primary productivity (GPP; the net change in standing vegetation per year), and to forward-calculate it using climate model forecasts.

Abstract.  “Several lines of evidence point to an increase in the activity of the terrestrial biosphere over recent decades, impacting the global net land carbon sink (NLS) and its control on the growth of atmospheric carbon dioxide (ca). Global terrestrial gross primary production (GPP)—the rate of carbon fixation by photosynthesis—is estimated to have risen by (31 ± 5)% since 1900, but the relative contributions of different putative drivers to this increase are not well known. Here we identify the rising atmospheric CO2 concentration as the dominant driver. We reconcile leaf‐level and global atmospheric constraints on trends in modeled biospheric activity to reveal a global CO2 fertilization effect on photosynthesis of 30% since 1900, or 47% for a doubling of ca above the pre‐industrial level. Our historic value is nearly twice as high as current estimates (17 ± 4)% that do not use the full range of available constraints. Consequently, under a future low‐emission scenario, we project a land carbon sink (174 PgC, 2006–2099) that is 57 PgC larger than if a lower CO2 fertilization effect comparable with current estimates is assumed. These findings suggest a larger beneficial role of the land carbon sink in modulating future excess anthropogenic CO2 consistent with the target of the Paris Agreement to stay below 2°C warming, and underscore the importance of preserving terrestrial carbon sinks.”

The paper predicted that the earth is going to gain nearly three times as much green matter as was forecast in the last (2013) IPCC report. It is noteworthy that Haverd’s model very faithfully reproduced the satellite-sensed changes in leaf area index shown by Zhu et al. (2016), which found the greatest greenings to be in the world’s semiarid tropics, tropical forests, and a smaller (but significant) increase in temperate latitudes. (I noted that paper here in 2018).

It’s very reassuring when two radically different methods—satellite sensing (Zhu) and a biophysical model (Haverd) come up with pretty much the same answer: we are greening up the earth fast, especially in critical tropical ecosystems.

Under a plausible emissions pathway, this will pull so much carbon dioxide out of the air that we could meet the Paris Accord of keeping surface warming below 2⁰C. Specifically, the authors wrote,

“[t]hese findings suggest a larger beneficial role of the land carbon sink in modulating future excess anthropogenic CO2 consistent with the target of the Paris Agreement to stay below 2°C warming…”

But they leave it the reader to do the math to see just how much their findings move the world toward Paris (which of course I will do later in this post).

Here are the amounts and causes of changes in past GPP:

Figure 1. Historical annual GPP according Haverd et al. Plotted here are the effects of leaf-level physiological changes directly stimulated by carbon dioxide (dark green), the overall increase in leaf matter i(light green), and the effects of climate change (tan)—i.e. the increase in temperature since 1900.

Haverd et al. give the previously accepted 1900-2006 increase in GPP as 17% +/- 4%. They used a model with land use, observed climate, and an interaction between changing CO2 and climate and found GPP likely increased 31%+/- 4%, or statistically speaking, roughly twice the increase in planetary green-ness that was previously accepted.

Figure 2. The left-hand image is Haverd et al’s map of model-calculated trends in Global Primary Productivity (the units are grams of carbon per meter squared per year), for 1980-2016. The right figures break down the causes: direct carbon dioxide effect (C), temperature effect (T), the interaction between the two (CxT), precipitation (P) and land use change (LUC). Of most interest here is the left-hand image which is very similar to Zhu et al’s satellite greening.

Obviously, if increasing atmospheric carbon dioxide caused so much planetary greening in 1980-2016 (Figure 2), it stands to reason that there’s going to be a much bigger change during the remainder of this century. Using a similar approach to what they applied to the past (but now climate forecasts are substituted for observations), they estimated the increase in green-ness that would result from either doubling atmospheric carbon dioxide from its preindustrial background, or putting the world on a low-emission pathway in which its concentration peaks at 440 parts per million (ppm) around 2050. (For reference, the annual average for 2020 is likely to be around 410ppm). The emissions scenario in Haverd is the UN’s Representative Concentration Pathway (RCP) 2.6, their lowest one.

University of Guelph Economist Ross McKitrick recently demonstrated that global carbon dioxide concentrations have been below every UN scenario generated from the 1990s onward, so the lower-peaking scenario isn’t just fantasy. (My own opinion, consistent with many others, is that we are currently running around RCP 6.0.)

In the doubling scenario (from a nominal 300 to 600ppm) they project a whopping 47% increase in green biomass from 2006-2099. That’s over and above the 37% increase already observed since 1900 (Figure 1). So we are going to come darned close to doubling the earth’s green vegetation since 1900 with no particular conservation effort.  Doubling of the CO2 concentration (relative to preindustrial) will likely occur sometime around 2070 or so.

The changes in green matter increase projected for 2006-2099 using RCP 2.6 are still huge. Read their words (and I hope your sitting down): “…we estimate a cumulative biophysical sink…equivalent to 17 years of anthropogenic emissions at current rates [emphasis added].

RCP 2.6 is associated with 2.4⁰C of warming (since preindustrial) by 2100. The goal of the Paris Agreement is to hold warming to two degrees or below. The reduction in warming from the equivalent of 17 years of zero emissions is, of course, spread through the century, but if it took place now (according to the UN’s models) it would reduce 0.5⁰C of the expected warming. The IPCC models have us warming at roughly 0.3⁰C/decade in the near term, but Haverd et al. tell us we will effectively have 1.7 decades of zero emissions thanks to greening.

A little math: 2.4⁰ (the UN’s expected RCP 2.6 warming to 2100) minus 0.5⁰ (the reduction in warming from 17 years of zero emissions) = 1.9⁰C of warming. Thanks to the wonders of photosynthesis on God’s getting-greener earth, we meet the Paris Accord.

That should have been front-page news. Instead, at least according to google, there hasn’t been one story about this astounding paper.


67 thoughts on “Greening the planet and slouching towards Paris?

  1. Then there are aquatic sinks. IPCC has always way underestimated carbon sinks. Earth’s air has been starved of photosynthesis feedstock for millions of years. Humans can help feed starving plants, algae and cyanobacteria.

    Naturally semiarid regions benefit the most, since leaf stomata lose less water when they need stay open less time to take in the CO2 they require to make sugar with sunlight and water.

    • …the clue was…..CO2 levels have been ~ stable

      CO2 was reduced to a level that was limiting….

      • Burning fossil fuels saves the planet from starvation !

        We must listen to the science, any skool kid knows that, even the ones which don’t go to skool.

      • We don’t have a quantitative knowledge of the carbon cycle, nor the water cycle but they pretend that we can project AGW 100y hence from a 30y calibration period.

        That is NOT science, it’s politics.

      • Besides sinks, science also doesn’t know all the nonhuman sources or their volumes. Dedicated satellite observations will help in that regard.

    • If CO2 does manage to warm the earth by a few tenths of a degree, tree lines will inch poleward and skyward.

  2. As solar power becomes cheaper I expect to see some fairly low cost desalination plants running water into the Sahel that allows a much faster greening of the Sahel, and possibly even into the Sahara. Wouldn’t that be nice? I’m not sure we have enough CO2 in the atmosphere for that yet, but hopefully in the near future.

    • Nice, but each desal plant greens so little more that you can forget it. Double nice, renewables are still to expensive and intermittent to do anything that coal cannot do more simply. Try some real world economics. Geoff S

      • Actually, it really depends on the greening approach. If you did something like a drip irrigation in a Eucalyptus heavy plantation you could manage a fairly decent return per gallon. The thing I think is going to make a difference will be the increased transpiration and secondary precipitation. But, I could be insanely wrong.

      • Not sure what you’re saying here Geoff. Wouldn’t the Sahel be one of the few places on Earth where solar would be more economic that shipping in coal, and the whole greening and water cycle, which is currently natural could be given a boost with some additional water on top of the continuing beneficial rise in the Keeling curve? Think of the real estate possibilities too – massive areas opening up in latitudes that will be beneficial for humanity when the inevitable 100,000 years of cold arrives.

        New Yorkers can keep New York …. good luck with that No Nukes people. Watch out for the polar bears.

        • The Sahara is often very hazy, from moisture in the air, or fugitive dust from the ground. During a couple of weeks I spent in Niger, the sun could not be seen during the day. Its general direction one could get, but it was very bright and hazy.

          Solar power systems reliant on a focusing of insolation are dysfunctional on those circumstances.

          • Thanks for the response (if you’re still here) but I was talking about the Sahel. Next question though – are there coal seams under there, and surely there must be oil?

      • An interesting concept comes to mind for water pumping into the Sahel using solar.
        Forget the intermediary transformations and devise a direct solar/thermal steam powered water pump. Have it pump water from a low tank into towers while the sun allows and then allow gravity to flow the water inland during the night to the next solar pumping station’s low tank and so on until you have enough water where you need it. Each stage could perform desalinization via solar or reverse osmosis as preferred.

    • Nice, but each desal plant greens so little more that you can forget it. Double nice, renewables are still to expensive and intermittent to do anything that coal cannot do more simply. Try some real world economics. Geoff S

      • It’s already pretty stinking cheap. Personally I don’t care where my electrons come from, but electrons that come from solar are not so expensive, especially when you have access to a large area with cheap land and lots of sunlight. If the solar panels provide shade to an area that tends to overheat you can do even better if your overall goal is vegetative growth. You put in 10 acres of semi dense panels powering desal plants and use drip irrigation on drought resistant grasses at the top of a sand dune and you get a great return. I suspect it would give at least 200 acres of greening. Perhaps it wouldn’t be worth the investment, I haven’t looked at the return on investment for that level of build-out. However, I suspect it is close.
        No-subsidy solar right now in those environments is already ~$20/MWh. Maybe it stays there, but it is also quite possible that it goes even lower.

      • Wow, I was way off. Curosry look at desal shows you need 4kWh to desal 1 cubic meter of water. A square meter of panel can produce 200kWh per year, or 50cubic meters of water per year. If you are in the Sahel you already have some water coming in, so you wouldn’t need to add a meter of water to natural rainfall, probably closer to 10-20cm. This would imply that each acre of solar panels could green 250-500 acres of land directly, before accounting for secondary water use from transipiration and evaporation and careful use of runoff.
        Right now solar is ~$1/Watt installed (at industrial scale), so the cost to restore land in the Sahel would be $800,000 for 500 acres. If you could take a 500 acre piece of non-productive land and convert it to productive land for $800k do you think it would be worth it? I’d say the numbers are not convincing either way, but they are close.
        A little bit could go a long long way.

      • There is none, cB. That’s a Greenie pipe dream unsupported by any real-world technology.

      • ChadB: Most of us here have read enough articles at WUWT to know that solar is pretty much unfit for purpose, so even if it has become “pretty stinking cheap” (disagree, BTW), it’s still pretty stinking useless.
        Your project, however, sounds very promising-off the shelf tech, and your infectious enthusiasm. What’s stopping you? Bet the ChiComs will finance you. Go build it, that’ll really show us!
        The enthusiasm of these renewable promotors is so boundless, it wears me out.

    • The only good method for using solar to desalinate water is to have the sun evaporate the water and then let it re-condense.

  3. The greening is an indication of how close the planet came to CO2 starvation. The anthropogenic increase has staved off extinction. That’s something worth rebelling against right there!

    • Richard, you are not cynical about the CO2 starvation meme! I vote for 1,000 ppm CO2 before the next glacial cycle of our current ice age! I wonder if they will credit Trump for this? NO?

      • Agreed, it always shocks me when i read some derp stating we need to go back to 280 or 250 or whatever, and i wonder how they feel that is a good idea?
        Patrick Moore has this part nailed, loved hearing him speak in person. One more ice age and maybe we are just all gone

  4. “Here we identify the rising atmospheric CO2 concentration as the dominant driver.”

    How can that be when the atmosphere, the ocean, and photosynthesis are all sinks? Rising atmospheric CO2 concentration means CO2 is being removed from the carbon cycle with the atmosphere as a sink. A higher rate of photosynthesis is like carbon sequestration and should cause a decline in atmospheric CO2. Also the amount of CO2 in fossil fuel emissions is relatively small in comparison with natural carbon cycle flows and it cannot at the same time explain rising atmospheric CO2, ocean acidification, and greening. We should look at geological flows more closely than just eruptions of land volcanoes. 80% of the world’s volcanoes are submarine and there are many other known flows that are not considered in climate science.


    1. The carbon cycle balance with and without fossil fuel emissions

    2. Atmospheric CO2 concentration is not responsive to fossil fuel emissions.

    3. Fossil fuel emissions can’t explain ocean acidification.

    4. Geological carbon changed atmospheric CO2 in the PETM

    5. Hydrothermal vents and hydrothermal plumes

    6. Geological carbon flows

    • Chaamjamal,

      There’s no need to decouple CO2 emissions from atmospheric CO2 concentrations. Sure, as CO2 increases, it’s rate of sequestration by biology also increases, but we’re still putting it into the air at a faster rate than it’s being sequestered, so disputing the connection between CO2 emissions and atmospheric CO2 concentrations only invites the denier epithet. This connection is a good thing since before man started emitting CO2, the rate of sequestration exceeded than the rate that CO2 was being added to the atmosphere by natural sources. This disparity is why the planet’s biomass got so close to extinction by running out of CO2 during the last ice age.

      The failure of climate science is not the fact that there are undisputed connections between CO2 emissions, atmospheric CO2 concentrations and the average surface temperature, but that the claimed size of those connections is so far from the ground truth and what the laws of physics can support, referring to this crap as science is an embarrassment to the scientific method.

  5. The greening from CO2 emissions is surely a good thing. Longer growing seasons and a bit more precipitation associated with a little warming is also beneficial to agriculture, the rest of the biosphere and mankind. Other than imagined worst case catastrophes that defy the laws of physics, there’s really no down side to CO2 emissions and a warming climate regardless of how the two are or are not connected.

  6. I hate people who push out sample- of – one personal experiences in support of ‘ the science’ but here goes. 45 years on and off at my country home – OK it was a wet February- but I’m sure I’m noticing a remarkable green efflorescence in the highways and byways year on year. Anyone else?

    • Make that a sample size of two. Here in the East San Francisco Bay where, in the last three years, we’ve had our man-made drought liar crisis severely compromised by a lot of rain (including two days this past week), I’ve never seen the foliage of pretty much everything to be so lush and fabulous, and I’ve been here for almost 40 years.

      Don’t you just hate this aspect of the “climate crisis (TM)”? We might be lucky enough that it sees off the democrat parasites in November though.

      Just vote.

      • Yeah, I’m sure my lawn is growing faster than it used to. I can barely keep up with it, and I just got about six inches of rain out of this passing weather front, which adds nitrates to the mix. More work, as soon as it dries out! 🙂

        • I don’t think mine’s growing any faster. It’s always fast this time of year, with alternating days of all-day drizzle then sun, the perfect combo. Then in summer the rain largely stops and it all turns brown, except for the weeds.

    • Sample of three — things are certainly not getting worse. Several trees I planted in 2005 (tuliptree, honeylocust, lacebark elm) are approaching 50 ft tall here in west MD in avg soil. Never fertilized or watered.

      • Here in calgary when it eventually warms up these days things get green fast
        It’s the problem with temperature, so cold in spring lately

      • Here in Melbourne Australia, a Manchurian tree planted 2005 has been trimmed again Also 50 ft high.
        Since early 1980s, wife and I have studied the ornamental Camellia as a hobby. Even been to China and Japan several times for authorised collecting, interacting mainly with world famous Kunming Institute of Botany at Director level. Although this is subjective observation, not controlled scientific measurement, I would be comfortable with a hypothesis that the Camellia has grown better, faster, greener in the last 25 years than in the 25 before that, including in many parts of the world where it has been introduced from native China and Japan. Often, while tending our Camellias, I have thought that CO2 fertilization must be a candidate, also so nice it is abundant and free. Geoff S

        • Thanks Geoff, always read your posts. Some wet years here I get wild lettuce stalks that grow 15 ft tall.

  7. “In the doubling scenario (from a nominal 300 to 600ppm) they project a whopping 47% increase in green biomass from 2006-2099”
    This is nearly identical to the average 46% increase in biomass from a 300 ppm rise in CO2 that was found by Idso and his team in his landmark study.

  8. That’s a Green New Deal I can get behind! Fossil fuels win again and I hope AOC appreciates it!

  9. “under a future low‐emission scenario,”

    Why is it that this paper is the climate related paper that uses the low-emission scenario?

    • I thought the same. Every paper to do with climate alarm seems to assume RCP8.5 as the baseline, so here we have a paper about benefits and they use the lowest scenario?

      What is the greening under RCP8.5, that is what i want to know so i can shove it down the throat of Canadian Green party whackadoodle Liz May?

      • Since you are dealing with a politician, just take 8.5 and divide it by 2.6 to get your multiplication factor. ;))

        • 8.5 divided by 2.6 then multiplied by 2? Just to be sure?
          Isn’t that climate science?

          • Depends on whether or not the correlation between 8.5, 2.6, and 2 “looks correct”. If it enhances the cause it is climate science. If it doesn’t support the cause it goes unreported because obviously it is not climate science.

  10. Any good news will be purposely smothered/discredited/ignored by the marxstream media (including so-called science-media).

  11. “Figure 2. The left-hand image is Haverd et al’s map of model-calculated trends in Global Primary Productivity”

    Looks like their “model-calculated trends” map completely eliminates the greening in the Sahel that has been acknowledged for twenty years.

    Typical model, based upon erroneous assumptions programmed into a self satisfaction feel good GIGO machine.

  12. Wow! for half a dozen years, I think I was almost the only one at WUWT clamoring about this and its grand effect. Forest extent expansion was 14% in 30 years in the 2013 -14 Nasa report. Googling number of trees on earth (3 trillion) I estimated 420 Billion new trees with an average age of 15 years. Looking at average tree growth weights, IIRC I computed ~17Gt (Billion tons) Carbon sequestration (actually 62Gt of CO2) for the expansion in tree numbers alone . I moderately assumed double this for the fattening of existing trees and mentioned this must also have an order of magnitude effect on plankton, etc on the sea.

    I reasoned, that since most of the new growth was in arid areas, the mechanism would be fringing growth progressively inward each fringe aided by shading/cooling from the last and that this means exponential growth!

    Further, It occurred to me that the sequestration was an endothermic process, i.e. caused cooling. I didnt get much further but I estimated the cooling (‘heat’ sequestration) for the new trees to involve energy equivalent to that contained in 17 billion tons of anthracite times 1.2 or 20 billion tons, because anthracite coal is 90% carbon and other non carbon aspects of plant growth are involved. This should be multiplied by perhaps 3 to include the rest of the greening and plankton not including sequestration in the carbonate parts of the latter.

    For those of you who read my offerings, I called it the Great Greening. I also predicted after mid century ” Garden of Eden Earth” would be upon us and with peak population settling in at 9B, it would be a world of plenty with all participating in an age of peace and prosperity.

    No wonder none of you we’re moved to comment!!

  13. “(My own opinion, consistent with many others, is that we are currently running around RCP 6.0.)”

    Is this correct? RCP 6.0 seems high.

  14. Fortunately, only in Greenie-weenie fantasyland is meeting the Paris Accords is anything that is even remotely necessary, or beneficial to either the planet or to humans.

  15. Gary Pearse said May 15, 2020 at 8:57 am

    “For those of you who read my offerings, I called it the Great Greening. I also predicted after mid century “Garden of Eden Earth” would be upon us and with peak population settling in at 9B, it would be a world of plenty with all participating in an age of peace and prosperity.”

    At my age (84) I don’t think I will be around to see it, but I wish the rest of you luck in this Garden of Eden scenario, all running around starkers. Don’t bother with the fig leaves. Beware of the tree in the middle of the Garden! Take no notice of talking serpents (or Greenies)!


    Dudley Horscroft

  16. Washington Gubernatorial Voters Pamphlet Candidate Statement

    My Washington gubernatorial candidacy is an attempt to debunk claim fossil emissions is an existential threat. That Al Gore’s “Inconvenient truth” is in fact a monumental lie.

    Ice core temperatures from four prior interglacial periods were higher than current levels with 300 ppm CO2 far lower than current 410 ppm. That during those periods the CO2 level was the result of increased out gassing from ocean when temperatures were warming and increased dissolution when temperatures were cooling. Both warming and cooling were driven by the Sun.

    It was the Sun that raised temperatures and CO2 levels after the last ice age, culminating in the Medieval Warming Period, Little Ice Age, and subsequent warming prior to significant fossil emissions. The increased fossil emissions have added to the Sun’s impact on CO2 over the last 60 years raising level to the current 410 ppm.

    However it’s the Sun not higher CO2 levels from increasing fossil emissions that can significantly increase global temperatures. The ~5 gigaton carbon (GtC) annual fossil emissions currently increase CO2 by ~2ppm. If emissions averaged 10 GtC over the next 50 years the additional 500 GtC would add 200 ppm raising the current level from 410 to 610 ppm, or from 0.041 to 0.061%, still a tiny fraction of the 96.5% CO2 that warms Venus.

    My Washington gubernatorial candidacy is an attempt to expose the futility of adding trillions more in an attempt to limit global warming by reducing that increase.

  17. Does this mean I’m going to have to mow my lawn more often?? If so, I’m NOT happy. More mowing time means less bourbon time.

  18. Freeman Dyson liked to compare the climatic (“models”) versus non-climatic (“scientific method”) effects of added CO2 to the environment. Our higher CO2 is “overwhelmingly beneficial” to biological life, which every indoor plant grower can prove. Rather than admit CO2 is (by definition) the opposite of a pollutant, the government still classifies it as a “pollutant” because . . . climate change. It’s 1984.

    To be fair, I wouldn’t want to live on a 1% CO2 atmosphere earth, but if we add 3ppm every year, we still have a few thousand more years to worry, and if we haven’t left earth by the year 5000 then I’ll consider our species a failure anyway.

  19. Leftist CAGW cultists hate discussing the incredible benefits of the CO2 fertilization effect.

    Leftists’ general response is to, response #1, rapidly pound cupped hands over theIr ears and scream, “la-la-la-la, I-can’t-year-you, la-la-la”, or, response #2, make absurd claims that any CO2 fertilization benefits are more than offset by CAGW-induced climatic events: droughts, wildfires, floods, tornadoes, heatwaves, hurricanes, etc., and then repeat response #1 when presented with evidence disproving response #2…..

    I’m surprised recent peer-reviewed CO2 fertilization papers (Zhu, Haverd) were even allowed to be published as they’re so detrimental to the CAGW narrative..

    An amazing fact is that the land area equivalent to the increase in global greening due to the CO2 fertilization effect is the size of the continental US….

    Imagine that…

  20. They dont predict a 475 increase post 2006, that 47% increase is since preindustrial: “fertilization effect on photosynthesis of 30% since 1900, or 47% for a doubling of ca above the pre‐industrial level” so no, bio mass wont be nearly doubled.

  21. With increased biomass, there will be increased leaf shedding which will produce increased amounts of CO2 when they rot. That is obvious.

    This is however not “CO2 production”. It is Carbon flux which is a result of greening which is a result of CO2 which has been released by means of increasing temperatures..

    The paper is a blah, blah throwing out nonsense obfuscation of the type chicken and egg: Which came first?


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