Source:
Climate Change Reconsidered II: Biological Impacts
Idso, Idso, Carter, and Singer, Lead Authors/Editors, 2014
http://www.nipccreport.org/reports/ccr2b/pdf/Full-Report.pdf
Summary:
https://www.heartland.org/media-library/pdfs/CCR-IIb/Summary-for-Policymakers.pdf
"Chapter 1. CO2, Plants, and Soils
• Results obtained under 3,586 separate sets of experimental conditions conducted on 549 plant species reveal nearly all plants experience increases in dry weight or biomass in response to atmospheric CO2 enrichment (henceforth referred to as “rising CO2”).
Additional results obtained under 2,094 separate experimental conditions conducted on 472 plant species reveal nearly all plants experience increases in their rates of photosynthesis in response to rising CO2.
• Long-term CO2 enrichment studies confirm the findings of shorter-term experiments, demonstrating that the growth-enhancing, water- conserving, and stress-alleviating effects of rising CO2 likely persist throughout plant lifetimes.
• Forest productivity and growth rates around the world have increased gradually since the Industrial Revolution in concert with, and in response to, the historical increase in the air’s CO2 concentration. Therefore, as CO2 continues to rise, forests likely will respond by exhibiting significant increases in biomass production and they likely will grow more robustly and significantly expand their ranges.
• Modest increases in air temperature tend to increase carbon storage in forests and their soils. Thus, old-growth forests can be significant carbon sinks and their capacity to sequester carbon in the future will be enhanced as CO2 continues to rise.
• As CO2 continues to rise, the productivity of grassland species will increase even under unfavorable growing conditions characterized by less-than-adequate soil moisture, inadequate soil nutrition, elevated air temperature, and physical stress imposed by herbivory.
• The thawing of permafrost caused by increases in air temperature likely will not transform peatlands from carbon sinks to carbon sources. Instead, rapid terrestrialization likely will act to intensify carbon- sink conditions.
• Rising CO2 likely will enhance the productivity and carbon sequestering ability of Earth’s wetlands. In addition, rising CO2 may help some coastal wetlands counterbalance the negative impacts of rising seas.
• Rising CO2 likely will allow greater numbers of beneficial bacteria (that help sequester carbon and nitrogen) to exist within soils and anaerobic water environments, thereby benefiting both terrestrial and aquatic ecosystems.
• The aerial fertilization effect of rising CO2 likely will result in greater soil carbon stores due to increased carbon input to soils, even in nutrient- poor soils and in spite of predicted increases in temperature. The carbon-sequestering capability of Earth’s vegetation likely will act as a significant brake on the rate-of-rise of the air’s CO2 content and thereby help to mute the magnitude of any CO2-induced global warming.
• Rising CO2 has significantly reduced the erosion of valuable topsoil over the past several decades; the continuing increase in atmospheric CO2 can maintain this trend and perhaps even accelerate it for the foreseeable future.
Chapter 2. Plant Characteristics
• Rising CO2 enhances plant growth, development, and ultimate yield (in the case of agricultural crops) by increasing the concentrations of plant hormones that stimulate cell division, cell elongation, and protein synthesis.
• Rising CO2 enables plants to produce more and larger flowers, as well as other flower-related changes having significant implications for plant productivity and survival, almost all of which are positive.
• Rising CO2 increases the production of glomalin, a protein created by fungi living in symbiotic association with the roots of 80 percent of the planet’s vascular plants, where it is having a huge positive impact on the biosphere.
• Rising CO2 likely will affect many leaf characteristics of agricultural plants, with the majority of the changes leading to higher rates and efficiencies of photosynthesis and growth as well as increased resistance to herbivory and pathogen attack.
• Rising CO2 stimulates photosynthesis in nearly all plants, enabling them to produce more nonstructural carbohydrates that can be used to create important carbon-based secondary compounds, one of which is lignin.
• Rising CO2 leads to enhanced plant fitness, flower pollination, and nectar production, leading to increases in fruit, grain, and vegetable yields of agricultural crops as well as productivity increases in natural vegetation.
• As rising CO2 causes many plants to increase biomass, the larger plants likely will develop more extensive root systems enabling them to extract greater amounts of mineral nutrients from the soil.
• Rising CO2 causes plants to sequentially reduce the openness of their stomata, thus restricting unnecessary water loss via excessive transpiration, while some plants also reduce the density (number per area) of stomates on their leaves.
• Rising CO2 significantly enhances the condensed tannin concentrations of the vast majority of trees and grasses, providing them with stronger defenses against various herbivores both above and below ground. This in turn reduces the amount of methane, a potent greenhouse gas, released to the atmosphere by ruminants browsing on tree leaves and grass.
• As the air’s CO2 content rises, many plant species may not experience photosynthetic acclimation even under conditions of low soil nitrogen. In the event that a plant cannot balance its carbohydrate sources and sinks, CO2-induced acclimation provides a way of achieving that balance by shifting resources away from the site of photosynthesis to enhance sink development or other important plant processes."
Source:
Climate Change Reconsidered II: Biological Impacts
Idso, Idso, Carter, and Singer, Lead Authors/Editors, 2014
http://www.nipccreport.org/reports/ccr2b/pdf/Full-Report.pdf
Summary:
https://www.heartland.org/media-library/pdfs/CCR-IIb/Summary-for-Policymakers.pdf