walter jehne

Walter Jehne – Die Bedeutung von Vegetation und fruchtbarem Boden für den Wasserkreislauf und das Klima

Walter Jehne – Die Bedeutung von Vegetation und fruchtbarem Boden für den Wasserkreislauf und das Klima

Auf unserer Tagung »Klima-Landschaften« Anfang Dezember war Walter Jehne dabei, Bodenmikrobiologe und Forscher im Bereich Erdsystemwissenschaft, der in wundervoller Weise Zusammenhänge zwischen Böden, Vegetation, Wasser und Klima aufzeigen kann. Welchen Einfluß spielen Böden und Vegetation bei der Klimaerwärmung/Klimakühlung und welchen Beitrag haben sie zum kleinen Wasserkreislauf?

Sein Vortrag ist nun auch mit deutschen Untertiteln von mir versehen und hier auf meinem Youtube-Kanal zu sehen.

Posted by Stefan in Klimaveränderung, Landwirtschaft, Natur, Präsentation, 0 comments
Präsentation: Wasser, Boden, Vegetation – Der Schwamm, der unser Klima verändern könnte. Walter Jehne

Präsentation: Wasser, Boden, Vegetation – Der Schwamm, der unser Klima verändern könnte. Walter Jehne

Hier ist mal eine wirklich beeindruckende, und vielleicht Welt-verändernde Präsentation von Walter Jehne.

Thematisch haben wir das in unserem Buch »Die Humusrevolution« ja auch schon mit dem New Water Paradigm heraus gestellt. Aber der Walter präsentiert diesen Themenkomplex noch mal ein bissl mehr in Richtung »Humusaufbau —> Pflanzenwachstum —> erhöhte (Evapo)Transpiration —> erhöhte Abkühlung —> reduzierte Wärmeabstrahlung am Boden im Vergleich zum halb-nackt-liegenden Acker/Land —> erhöhte Wolkenbildung —> erhöhte Sonnenlichtreflexion durch die Wolken und mehr Niederschlag —> geringere Sonneneinstrahlung —> Klima-positive Entwicklung(en)«. (Sehr stark verkürzt)

Sollte das so stimmen, wie er das darstellt, dann sollten wir von der »Single Story« der CO2-Problematik uns hinwenden auf eine ganzheitlichere Sichtweise, wo Wasser, Vegetation und Böden im Zentrum des Geschehens rücken.

Seine Präsentation gibt’s nun auch in deutlich verkürzter Form auch auf deutsch (und leider ohne Hinweis auf den Ursprung der Inhalte, Zahlen, Daten, Fakten).

Aus einem Interview von ihm habe ich mal einige Stichworte rausgeschrieben. Was in dick ist, bräuchte meines Erachtens nach einen wissenschaftlichen Nachweis:

  • Water is governing 95 percent of the heat dynamics of the earth 
  • Solar radiation
    • at the top of the troposphere: 342 W/m2
    • water vapour in atmosphere rises temperature from -18 to 15 °C (+ 33 °C)
    • for stable climate, 342 must go out again
    • instead, 3 W less re-radiation = 1% of the incident solar radiation
    • with an increase of the natural hydrological processes, we can readily get to that one percent
      • latent heat flux of transpiration = 85 W/m2 from surface back out to space
      • if we increase transpiration globally by 5%, that would effectively put another 3 W/m2 out to space 
      • be increasing clouds by 2%, we would get an additional 3 W/m2 reflected back out of space 
  • water vapour
    • 80% of the natural greenhouse effect results from water vapour in the atmosphere
    • rel. constant over time at 4%
    • 1 gram of water can absorb 590 calories of heat energy
    • power of water (molecule) vapor to absorb and transfer heat is 20 times higher than that of CO2 (see below)
    • 40.000 ppm of water vapor to 400 ppm of CO2 —> power of water vapor
  • CO2
    • CO2 governs ~20% of the greenhouse effect
    • large variations over time
    • high concentrations at the beginning
      • drawn down by the formation of corals, limestone, chalk
      • since 420 million years by plants on land and the formation of soils
    • a CO2 molecule can absorb 1/8 of the heat of a water molecule
    • a CO2 molecule weight three times as much as a water molecule
  • when water evaporates, that heat gets transferred into the atmosphere, where is releases energy through condensation
    • that makes storms
    • but most of that gets dissipated back out of space through the upper atmosphere
      • this process accounts for about 24% of the Earth’s natural hydrological cooling 
    • clouds
      • = high albedo
      • 50% of the planet at any given time is covered by clouds
        • with a diminuishing amount 
        • 1/3 of the solar radiation is relefected out to space (by the clouds only?)
          • thus, more clouds, more reflection, more »cooling«
      • humid haze 
        • nucleated on aerosols and dust particulates
          • micro-droplets and thus too small and light to fall
          • electrostatically charged so they repel each other
          • when liquid, they absorb heat from the sun
          • when gaseous, they absorb re-radiated infrared radiation from the Earth
        • pollutant brown haze from Cairo to Beijing
          • Asian brown haze contains up to 4% moisture plus pollutants
          • »takes out« the precipiatation nuvlei so water in the atmopshere does not fall as rain
      • a million cloud micro-droplets need to coalesce to form a raindrop to begin falling
        • for that, we need precipitation nuclei
          • 1) ice crystals, 2) salts, 3) certain bacteria
          • by far the most effective nuclei in cloud chamber studies are the highly hydroscopic bacteria Aerobacter 
            • they are produced in the stomata of trees
            • rainfall in the Amazon is largely a symbiotic, bacterially driven process
            • proof: deforestation on an island leads to diminished rainfall; reforestation to a restoration of rainfall, for example Madeira 
    • oceans
      • cover 71% of the planet
      • evapotranspiration only possible from a two-dimensional monomolecular layer = limited physical dimension
      • surface water is always cooled from water below
    • trees
      • have a leaf area 10 times greater than the land’s surface area
      • three-dimensional process
      • longevity of green growth = four-dimensional
      • thus, much greater potential than oceans
  • soil
    • comparison to a cathedral
      • stones = building blocks = anorganic compounds
      • soil organic matter = cement, that holds the stones together
      • the void = all that empty space in the soil (66% of a healthy soil is just space, air, and partially filled with water)
      • avaiability of nutrients is related to how much surface area of the mineral particles is exposed
      • nutrients = often cations = held as if by Velcro
      • >80% of a soil’s biofertility depends on this surface exposure
      • creating cathedrals = spaces and surface = fundamental for both soil hydrology and biodertility
    • North America: 10-15 meters deep organic soils with 8% SOM within 10.000 years
  • land
    • 5 billion hectares of land degraded, turning 40% of the Earth’s land surface into desert and wasteland
    • 8 billion hectares of old growth forest, 6.3 billion were cleared
    • now at 3 billion hectares »restored«
    • 5 billion hectares of grasslands originally—> how much destroyed, degraded?
      • at times of the roman empire, lions from the libyan savannahs (what has changed that?) (!!!)
      • degradation = decarbonization = less water infliration, retaining, making available —> further degradation
    • if we degrade an area and leave it bare, it will absorb incident solar radiation and heat up and and enormously re-radiate back infrared radiation
  • CO2
    • we are emitting 130 billion tons of carbon emitted from the biosystems (?)
    • fossil fuel emissions are 10 billion tons of carbon per annum
    • photosynthesis draw down 120 billion tons of carbon per year
    • atmosphere:
      • 750 billion tons
    • oceans
      • 38.000 billion tons
      • 1/3 (???) of the man made CO2 emissions have been absorbed and buffered by the oceans
      • when CO2 concentration in the atmosphere diminish, oceans will release CO2 back into the air
      • 93% of the additional heat that we’re generating and retaining is being absorbed by the oceans (!!!)
        • when temperatures rise – we see only 7-10% of the total effect
      • in terms of carbon, energy and heat dynamics, water is the elephant in the room
    • ABC(D) of carbon sequestering
      • Agriculture
      • Burning (oxidation, decomposition, oxidation of plant material)
      • Carbon biosequestration
      • Dividend
        • + biofertility, microbial activity, surface area, moisture-holding capcity, ….
        • instead of »burning« 100 to 120% of the carbon, we could fix 60-70% in the soil
Posted by Stefan in Artikel, Garten, Klimaveränderung, Landwirtschaft, Natur, Pilze, Präsentation, Technik, Tiere, Wirtschaft, 0 comments