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Global Vegetation Decreasing, As The World Gets Greener (Or Something Like That!)

August 16, 2019
tags:

By Paul Homewood

 

h/t AC Osborn

 

 

The Mail gives uncritical coverage to the latest bit of  junk science:

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Plant growth has decreased by 59 per cent worldwide since 1999 due to a lack of water in the atmosphere, a new study suggests.

Experts studied four global climate datasets to try and uncover why vegetation growth has stalled in the past two decades.

They found that a drop in levels of water vapour had stopped plants from being able to photosynthesise.

Photosynthesis is used by plants, some bacteria and single-celled organisms to draw energy from sunlight, taking in carbon dioxide and water in the process.

Researchers from Sun Yat-sen University in Zhuhai, China, found that the decline is linked to a vapour pressure deficit (VPD) in the atmosphere.

VPD is the difference between the pressure that would be exerted by water vapour when the air is fully saturated and the pressure it actually exerts.

This has increased sharply over more than 53 per cent of vegetated areas since the late 1990s.

When this deficit increases, the pores on the surface of leaves that taken in carbon dioxide and release water vapour close up, resulting in lower rates of photosynthesis. 

https://www.dailymail.co.uk/sciencetech/article-7359941/Global-vegetation-not-grown-20-years-thanks-dry-air.html

 

These findings, however, are in stark contrast to a study in 2016, which found that the world had massively been greened by extra CO2 in the atmosphere, as the BBC reported:

 

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Carbon dioxide emissions from industrial society have driven a huge growth in trees and other plants.

A new study says that if the extra green leaves prompted by rising CO2 levels were laid in a carpet, it would cover twice the continental USA.

Climate sceptics argue the findings show that the extra CO2 is actually benefiting the planet.

But the researchers say the fertilisation effect diminishes over time.

They warn the positives of CO2 are likely to be outweighed by the negatives.

The lead author, Prof Ranga Myneni from Boston University, told BBC News the extra tree growth would not compensate for global warming, rising sea levels, melting glaciers, ocean acidification, the loss of Arctic sea ice, and the prediction of more severe tropical storms.

The new study is published in the journal Nature Climate Change by a team of 32 authors from 24 institutions in eight countries.

It is called Greening of the Earth and its Drivers, and it is based on data from the Modis and AVHRR instruments which have been carried on American satellites over the past 33 years.The sensors show significant greening of something between 25% and 50% of the Earth’s vegetated land, which in turn is slowing the pace of climate change as the plants are drawing CO2 from the atmosphere.

Just 4% of vegetated land has suffered from plant loss.

https://notalotofpeopleknowthat.wordpress.com/2016/04/29/rise-in-co2-has-greened-planet-earth/

 

We have, of course, often been warned that a warmer atmosphere can hold more water vapour, which is then blamed for heavier rainfalls.

Now they are trying to argue that the air is drier!

 

There is one key chart in this new paper, which underlines just how bad it is. It concerns oceanic evaporation, which is the most important factor, as the paper explains:

A change of oceanic evaporation is the most important mechanism for the observed decrease in actual water vapor pressure over the land (18). Oceanic evaporation is the most important source of atmosphere water vapor, and approximately 85% of atmospheric water vapor is evaporated from oceans, with the remaining 15% coming from evaporation and transpiration over land (19). Most of the moisture over land is transported from the oceans, which accounts for 35% of precipitation and 55% of evapotranspiration over land (19).

 

And what does the graph show?

 

F2.large

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https://advances.sciencemag.org/content/5/8/eaax1396

 

A drop in evaporation in the 1960s and 70s, when the world was cooling, followed by a rise when the PDO and AMO kicked into warm phases, thus leading to a warming period.

And since 1998, another drop. This incidentally indicates that oceanic warming has stopped since 1998, which would confirm the global temperature pause still evident from satellite measurements. Physics, after all, tells us that warmer oceans lead to increased evaporation.

Either way, it is clear that we have a cyclical pattern, and that reduced evaporation since 1998 has nothing at all to do with global warming. Indeed, quite the opposite – when the world was warming between 1979 and 1998, evaporation increased.

But if they admitted that, they would quickly kiss goodbye to their next grant cheque!

32 Comments
  1. John Palmer permalink
    August 16, 2019 11:43 am

    So… if you’re an AGW Alarmist, you can have your cake AND eat it!
    Two LL’s and one X is how we spell it.

  2. Pancho Plail permalink
    August 16, 2019 12:00 pm

    Well there is a reason for warmists to celebrate. That will counter global warming then, since water vapour is a far more potent contributor to the greenhouse effect than CO2, or so we have been told repeatedly in the past.

  3. August 16, 2019 12:00 pm

    Reblogged this on Climate- Science.press.

  4. HotScot permalink
    August 16, 2019 12:05 pm

    If, as John Tyndall discovered, water vapour is the principle atmospheric gas controlling the earths temperature, then surely attention should be diverted from CO2 to atmospheric water vapour loss to identify the culprit of climate change.

    • JimW permalink
      August 16, 2019 12:15 pm

      Well this paper ‘proves’ ( ho ho) that decreasing evaporation over the oceans causes water vapour decrease, which causes temperature drop, which causes oceans to cool, which causes water vapour to drop…..we’re all doomed I tell you, its going to freeze!!!

  5. Graeme No.3 permalink
    August 16, 2019 12:12 pm

    WoW! Less humidity must mean less evaporation, therefore they are claiming that the Earth is cooling despite (or because of) the rising CO2 level.
    That won’t get them a date with Greta.

    • Gerry, England permalink
      August 16, 2019 1:59 pm

      Saint Greta doesn’t do science – she just reads the treaties and the agreements so this would pass her by. Has the boat sunk yet? I wonder if there will be frequent flypasts to check on progress meaning that there will be no saving of the blessed gas.

      • Derek Walton permalink
        August 16, 2019 2:20 pm

        Guido reports that the people bring the boat back have all flown to NY – so producing 3 times the emissions (one way) as opposed to her flying alone

      • Mike Ellwood permalink
        August 16, 2019 9:08 pm

        @Dave Ward: I don’t of course approve of the PR stunt that this sailboat trip is, but that’s a neat little chart.

      • August 18, 2019 7:41 pm

        I wonder how much it cost Greta to hire a hi-tech trans-Atlantic racing yacht?
        Her parents must give a mind-boggling pocket-money allowance!
        By contrast a return economy-class ticket on a cheap airline is a few hundred quid at the most.

  6. saparonia permalink
    August 16, 2019 12:18 pm

    Hahaha they’re in their death throes trying to validate a lie.

  7. Malcolm Bell permalink
    August 16, 2019 12:19 pm

    The trees round me, and the plants in my harden are growing as never before.

    • Dave Ward permalink
      August 16, 2019 2:12 pm

      So are the weeds…

  8. Adrian, East Anglia permalink
    August 16, 2019 12:23 pm

    I know I’m getting on a bit in years, but now I am utterly confused. As Paul points out, last week we were told that warmer air holds more water vapour so we can look forward to a greater number of ‘extreme’ rainfall events and increasing prospects of ‘catastrophic’ flooding. Now we are told that warmer air holds less water vapour and we can look forward to all the plants dying. Since we are expected to eat less meat and more plant produce, that prediction would seem to augur badly for both man and beast. Might be a good idea to enjoy a nice plate of steak and chips before everything snuffs it!!

  9. August 16, 2019 12:45 pm

    You couldn’t make it up – unless you’re an alarmist on the gravy train.

  10. Diogenese2 permalink
    August 16, 2019 1:18 pm

    The headline “Global Vegetation growth decreased 59% in 20 years” ( what!) was not made up. I searched the paper to find this figure. It relates to the NDVI (look it up) and it appears that 59% of vegetation areas (spatial) showed a decrease (variable but nowhere extreme) from 1999 to 2015. The mail “journalist” simple hadn’t got a clue what he was writing about.
    Also from 1982- 1998 84% of vegetation areas showed an increase! So we are still ahead.
    I also noted in the conclusions “ large scale constraints of NDVI changes on vegetation growth have not yet been quantified”
    I spell it with two LLs and OCKS.

  11. Paul Petley permalink
    August 16, 2019 1:36 pm

    The “research” appears to be saying that the air temperature increase taken from 4 meteorlogical datasets should indicate a higher level of water vapour being able to be held in saturated air.The actual measured amount of water vapour as a percentage of the theoretical saturation point is reducing hence the vapour pressure deficit (VPD) is increasing.
    Well my “logic” follows that this probably indicates the temperature data is “over recorded” and it is not as warm as is being claimed. Takes me back to the recent post on Homogenised Data!

  12. Joe Public permalink
    August 16, 2019 1:44 pm

    IPCC August 2019:

    Climate Change and Land

    An IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems
    Summary for Policymakers:

    “Globally, vegetation greening has occurred over a larger area than vegetation browning (high confidence).”

    Click to access 4.-SPM_Approved_Microsite_FINAL.pdf

    • Latus Dextro permalink
      August 19, 2019 3:03 am

      Heck, I loathe those pontificating UN IPCC statements ‘high confidence’ … a transparent word ploy to mimic statistical confidence when it is nothing of the sort, merely handwaving agreement. It is as bad as ‘sustainable’, which Left never does, and the use of the word ‘civil’ an intentional ploy to imply civilised, which a vast array of Soros funded NGO’s with UN ECOSOC accreditation are a fair way from. The UNEP loves ‘divestment’ and the UNFCCC foisted the defined terms ‘climate change’ and ‘climate variability’ on a suspecting World.
      Alinsky stated, control the language, you control the people.

  13. August 16, 2019 1:46 pm

    <i.Plant growth has decreased by 59 per cent worldwide since 1999 due to a lack of water in the atmosphere, a new study suggests.

    There was also a big drop in the number of serious (water-carrying) US land-falling hurricanes in that period, until 2017.

    • dave permalink
      August 16, 2019 2:23 pm

      The stomata (in ‘mesophytes’) open and close according to the amount of water IN THE PLANT, not according to the amount of water (vapour) IN THE AIR.

      It is true that transpiration needs to be reduced by the plant during extremely hot and dry weather, or when there is no water in the ground for the roots. The sort of natural fluctuations of relative humidity that were studied are trivial by comparison. Hence the caveat in the paper that there is no known quantitative relation between such fluctuations and actual growth. Which is another way of saying, “We have nothing better to do with our hard-earned qualifications than produce useless speculations.”

      • dave permalink
        August 16, 2019 2:37 pm

        It also occurs to me that the idea that a Daily Merde journalist or his readers would know ANYTHING AT ALL about Plant Physiology, is utterly risible.

  14. Henning Nielsen permalink
    August 16, 2019 2:15 pm

    I guess it’s just an attempt at dry humour.

    • dave permalink
      August 16, 2019 3:48 pm

      I am still startled by how totally bonkers this whole story is.

      Low humidity and high temperatures are GOOD. They cause fast transpiration which aids the plant, as it pulls water through the system and carries nutrients along. It is only when there is drought (dry soil) that this system will need to self-regulate. Or extreme conditions when the leaves themselves struggle to function.

      Plants run into trouble precisely WHEN there is 100% humidity in the micro-climates of the stomata. The stomata do not take in water, they chuck it out.

    • Bertie permalink
      August 16, 2019 7:48 pm

      If only!

  15. swan101 permalink
    August 16, 2019 5:16 pm

    Reblogged this on ECO-ENERGY DATABASE.

  16. David Kendrick permalink
    August 16, 2019 7:30 pm

    Went to the actual paper, all the researchers confirmed is that with their dataset the fall in global temperature since the mid 1990s align exactly with solar activity over the oceans which is good but not intended, Piers Corbyn was right
    https://advances.sciencemag.org/content/5/8/eaax1396

    “A change of oceanic evaporation is the most important mechanism for the observed decrease in actual water vapor pressure over the land (18). Oceanic evaporation is the most important source of atmosphere water vapor, and approximately 85% of atmospheric water vapor is evaporated from oceans, with the remaining 15% coming from evaporation and transpiration over land (19). Most of the moisture over land is transported from the oceans, which accounts for 35% of precipitation and 55% of evapotranspiration over land (19). We analyzed long-term changes of oceanic evaporation based on a global oceanic evaporation dataset [Objectively Analyzed Air–Sea Fluxes (OAFlux)] (20). The almost 60-year time series showed that the decadal change of global oceanic evaporation (Eocean) was marked by a distinct transition from an upward to a downward trend around 1998 (Fig. 2A). The global oceanic Eocean has decreased by approximately 2.08 mm year−1, from a peak of 1197 mm year−1 in 1998 to a low 1166 mm year−1 in 2015 (Fig. 2A), and 76% of the sea surface revealed a decreased Eocean after 1999 (Fig. 2B). Rhein et al. (16) reported stalled increases of sea surface temperature after the late 1990s based on multiple global datasets, which substantially limited oceanic evaporation (20). ”

    The reset is a projection based on what might have been using their own model generated by computer learning algorithms, you tend to suffer confirmation bias by setting recursive leaning, threshold levels to meet expected outcomes in their “terrestrial ecosystem models” based on satellite data. The fact of the matter is nothing beats long term study with labs in situ.

  17. Arthur Clapham permalink
    August 16, 2019 9:32 pm

    Injected CO2 into into large glasshouses increases productivity of crops by large amounts,I believe it was developed by the Dutch who are World class Horticulturists.Time to Green up!

  18. mikewaite permalink
    August 16, 2019 10:12 pm

    Bit perplexed to be honest . Are the authors saying that air blowing over a cold ocean will pick up more water vapour than if the ocean is warm , and that on meeting a warm front , will deposit water as rain? The opposite of what we were taught at schools : warm, wet air deposits rain when meeting a cold front or ascending a slope such that the air temperature falls with elevation.
    The saturated vapour pressure of pure water as a function of temperature, from the “Rubber Book” and Wiki:

    T, (C) P (kPa)
    0 0.6113
    5 0.8726
    10 1.2281
    15 1.7056
    20 2.3388
    25 3.1690
    30 4.2455
    35 5.6267
    40 7.3814
    45 9.5898
    50 12.3440

  19. August 17, 2019 1:59 am

    Here’s a good explanation of how the media has misinterpreted the paper –

    Rising Water Stress Slowed Down RATE Of Increase In Greening – World Still Greening Fast

    “it’s because it is a map of a change in the RATE of greening”

    https://www.science20.com/robert_walker/rising_water_stress_slowed_down_rate_of_increase_in_greening_world_still_greening_fast-240741

  20. Arthur Clapham permalink
    August 17, 2019 3:14 pm

    Do these Scientists ever venture out of doors, I call them the POBs,or Perpetrators of Bullshit. Having lived in a rural area since the 1940s I have seen Cereals Potato’s and Sugar Beet etc increase 3 or 4 fold. Get out more and see how Real people live!!

    Rudolf Hucker.

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