Plant Evapotranspiration Reduction Causes Global Warming, not CO2 GHG

Wryheat note: The following is an original research paper written by David Motes, a chemical engineer with 43 years professional experience. Below I provide the paper abstract with a link to the full paper as a PDF file. The full paper discusses nine problems with the Greenhouse hypothesis and then presents Motes’ alternative hypothesis. Mr. Motes may be contacted at

Plant Evapotranspiration Reduction Causes Global Warming, not CO2 GHG
by David Motes

Anthropogenic (manmade) Global Warming (AGW) has many causes. CO2 drives recent global warming by Plant Evapotranspiration Reduction (PER), not CO2 Green House Gas (GHG) theory. For example, the irrefutable correlation between global temperature and CO2 concentration for the last 800+ thousand years can only be explained by plant evapotranspiration increases / decreases and not by the prevailing CO2 GHG effects. The prevailing GHG theory cannot explain why CO2 increased or decreased or the carbon source prior to fossil fuel emissions, but PER does. Quantitative evidence for PER driving global warming over CO2 GHG follows:

  1. Using a NOAA (National Oceanic and Atmospheric Agency) energy balance, the scientific consensus 0.70%/year plant water use efficiency increase (evapotranspiration reduction) caused by higher CO2 generates a calculated temperature rise 12 times the actual measured temperature rise.
  2. Similarly, the measured 0.23%/year deforestation and land use change (causing same plant evapotranspiration 0.23%/year reduction) generates a calculated temperature rise 3 times the actual measured temperature rise. From scientific consensus, global development, deforestation, commercial farming, and commercial ranching have reduced plants (consequently evapotranspiration) since the 1960 industrial global expansion. Explaining the 12 and 3 factors:
    A. The actual temperature increase was less due to increasing infrared radiation emitted by the atmosphere to space from that same temperature rise.
    B. Terrestrial biomass increases in deserts and arid lands partially offset the measured evapotranspiration reductions.
  3. Only 8% photosynthesis reduction is equivalent to all 2020 fossil fuel CO2 emissions.
  4. Water vapor is 192 times stronger GHG than CO2 when you factor in both infrared absorbances and atmospheric concentrations. Consequently, CO2 GHG contributes only ~0.3% to AGW, balance driven by PER.
  5. The PER impact on global warming is demonstrated in real life at many locations such as city centers being 1-3 °C warmer than the surrounding suburbs or countryside. Secondly, the air is 3-4oC cooler above a green grass lawn vs a black asphalt parking lot. PER provides an explanation for the undeniable Global Warming that fits all the scientific data (climate history, carbon sources, carbon mass balances, energy balances, GHG parameters, humidity data, etc.) as quantified and explained in this engineering and scientific study. “Greening” the earth (increasing plant life) is less expensive and substantially more effective than just reducing annual fossil fuel CO2 emissions (contributes only 1% of existing atmospheric CO2).

Quantified problems with the proposed CO2 annual emission reduction
plans follow:

  1. Will certainly fail by focusing on the 1%/year contribution and foolishly ignoring the 99% existing atmospheric CO2.
  2. Focuses solely on reducing the 8% CO2 emissions driver, while ignoring the 92% plant life CO2 driver. Prior to attempting to resolve the current global warming problem, we should identify, quantify, and confirm the root cause(s) and magnitudes. Then, solutions become clearer and more cost effective.

Read the full paper:

CO2 & Global Temperature 19apr2021