According to Idso, CO2 levels would have to surge 36 times above the present concentration before they would even begin to pose a mild health concern. "That value (i.e., 15,000 ppm) will never occur, given it is a factor of ten above the approximate 1,500 ppm atmospheric CO2 limit that scientists think is possible if society utilized all of the currently-known fossil fuel reserves on the planet," he explained. (Related: Craig Idso: High CO2 in summer lessens temperature stress in plants.)
Subsequently, if CO2 is low in the atmosphere, it poses a threat to humanity.
"The more CO2 the better, in other words," he pointed out in a blog post on Watts Up With That. "CO2 literally is the 'food' that sustains essentially all plants (and animals that consume plants, including humans) on the face of the Earth. And when that food supply is diminished, nature begins to diminish."
He cited a 2020 study that examined the impact of low levels of CO2 on African wood-sorrel (Oxalis pes-caprae). This plant species was a key carbohydrate source for humans during the Middle Pleistocene as they are harvested for their edible underground storage organs (USOs).
The researchers grew specimens of the yellow flowering plant for three months in mini open-top-chambers with under-average CO2 concentrations of 227, 285, 320 and 390 parts per million (ppm), where all plants received sufficient water and nutrients.
According to Idso, the plants grown under reduced concentrations of CO2 exhibited "significantly decreased plant biomass and bulb yield."
"With respect to the human impact of such growth reductions caused by low CO2, the authors noted that lower CO2 concentrations affect both the value of USOs as sources of carbohydrates and the effort that would have been required to harvest sufficient biomass to attain daily calorific requirements,'" Idso said. "And in regard to the latter, they calculate the time required to harvest 2,000 calories was more than doubled when CO2 was decreased from 400 to 180 ppm."
The paper concluded that the reduction in the CO2 content of the atmosphere will negatively impact the current state of nature and decrease food supply. Higher CO2 in the air leads to greater water use efficiencies and boosts the planet's ability to withstand better environmental stresses such as drought, disease, high soil salinity, low light intensity, ozone pollution, heatwaves and UV-B radiation.
The study further discredits climate experts' assertion that carbon is the main contributor to climate change.
In a separate blog, Idso cited studies that proved how elevated levels of CO2 in the air boost plants' medicinal value.
One of the studies examined the nutritive values, phytochemicals (i.e., pigments, phenolics, flavonoids, vitamins, mineral profiles and essential oil yields) and antioxidant activities of caraway sprouts and mature plants.
Authors of the study explored the hypothesis that the rising levels of atmospheric CO2 typically promote plant photosynthesis and the production of secondary compounds.
The research team grew caraway in controlled-environment chambers under ambient (400 ppm) or elevated (620 ppm) CO2 conditions. They were harvested after nine or 45 days (as sprouts or mature plants, respectively).
The researchers found that "elevated CO2 provoked changes in the phytochemical contents of caraway plants, particularly at the sprouting stage, thus improving their nutritive and health-promoting properties." Caraway is used in herbal mixtures as a drug for digestive, carminative and lactogenic disorders.
Idso pointed out that there are other studies that can prove how beneficial high levels of CO2 are for the environment and health.
"Over the past quarter-century, I have archived a number of such studies on my CO2 Science website under the topic Health Effects (Carbon Dioxide: Health-Promoting Substances, Medicinal Plants). It will give you a whole new perspective on the many benefits of atmospheric CO2 enrichment," he said.
More climate-related research can be found at ClimateScienceNews.com.
Watch this video that talks about geoengineering as the real cause of climate change.
This video is from the Free4eva Media channel on Brighteon.com.