IN THIS ISSUE:
- Plants Are Using Much More CO2 Than Climate Models Assume
- Recent Methane Increase Is Due to Natural Sources, Not Natural Gas Development
- CO2 Saturation Refutes Temperature Forcing Fears
Plants Are Using Much More CO2 Than Climate Models Assume
A study recently published in the journal Nature finds plants have been absorbing 31 percent more carbon dioxide from the atmosphere than previously assumed and modeled.
The international team of researchers, led by Jiameng Lai at Cornell University, examined gross primary production (GPP), the largest carbon flux (carbon sink and cycling) in the biosphere. The GPP is calculated in petagrams of carbon per year, with one petagram equaling about 1 billion metric tons, approximately the amount of carbon dioxide (CO2) emitted annually from 238 million internal combustion engine vehicles.
The research team used a new, integrated model they developed to track the cycling of carbonyl sulfide, or OCS, “from the air into leaf chloroplasts, the factories inside plant cells that carry out photosynthesis,” SciTechDaily reports. OCS is a good proxy for CO2 and is more easily measured. Science Direct:
The research team quantified photosynthetic activity by tracking OCS. The compound largely follows the same path through a leaf as CO2, is closely related to photosynthesis, and is easier to track and measure than CO2 diffusion. For these reasons, OCS has been used as a photosynthesis proxy at the plant and leaf levels. This study showed that OCS is well suited to estimate photosynthesis at large scales and over long periods of time, making it a reliable indicator of worldwide GPP.
To fill in the model’s parameters on plant growth and GPP, the scientists used plant data from a variety of sources. To verify the accuracy of the inputs, the researchers compared them with high-resolution data from environmental monitoring towers instead of satellite observations, which can be hampered by cloud cover, especially in tropical regions.
Whereas historically the GPP has been thought to be approximately 120 petagrams of CO2 per year, their results suggest the Earth’s plant life is removing between 157 and 175 petagrams of CO2 per year. Whence the difference? They write,
Our global GPP is higher than satellite optical observation-driven estimates (120–140 PgC yr–1) that are used for Earth system model benchmarking. This difference predominantly occurs in the pan-tropical rainforests and is corroborated by ground measurements, suggesting a more productive tropics than satellite-based GPP products indicated. As GPP is a primary determinant of terrestrial carbon sinks and may shape climate trajectories, our findings lay a physiological foundationon which the understanding and prediction of carbon–climate feedbacks can be advanced.
It seems that persistent cloud cover in tropical regions often distorts satellite mapping of plant life.
“Figuring out how much CO2 plants fix each year is a conundrum that scientists have been working on for a while,” Lianhong Gu, a coauthor of the study and a distinguished scientist with the Environmental Services Division of the Oakridge National Laboratory (ORNL), said in a press released quoted by SciTechDaily. “The original estimate of 120 petagrams per year was established in the 1980s, and it stuck as we tried to figure out a new approach.
“It’s important that we get a good handle on global GPP since that initial land carbon uptake affects the rest of our representations of Earth’s carbon cycle,” Gu said. “We have to make sure the fundamental processes in the carbon cycle are properly represented in our larger-scale models. … For those Earth-scale simulations to work well, they need to represent the best understanding of the processes at work.”
Peter Thornton, who leads the ORNL Earth Systems Science Section but did not participate in the research, agrees properly understanding and accurately modeling the carbon cycle is critical to an analysis of climate change and its impacts.
“Nailing down our estimates of GPP with reliable global-scale observations is a critical step in improving our predictions of future CO2 in the atmosphere, and the consequences for global climate,” Thornton told SciTechDaily.
Sources: Nature; SciTechDaily
Recent Methane Increase Is Due to Natural Sources, Not Natural Gas Development
An international team of researchers from universities and research institutes in the United States, New Zealand, Japan, and Germany conducted a careful molecular analysis of the types of carbon atoms contained in recent methane concentrations to determine the source of an increase in recent years. The research yielded a surprising result. The record-high growth rate of methane measured between 2020 and 2022, which climate alarmists have attributed to fracking and methane leaks from oil and gas operations, has a natural source.
Carbon and methane ratios from the National Oceanic and Atmospheric Administration’s Global Greenhouse Gas Reference Network were run through a model to understand the recent drivers of atmospheric methane growth. Record rates of growth ware recorded in 2020 through 2022, but that reflected a longer but more modest growth trend since 2007.
The University of Colorado at Boulder research lab has been collecting air samples for chemical analysis from 22 sites around the world every week or two since 1998. Methane from fossil fuels has more carbon-13 isotope than background air levels, while, by contrast, methane from microbial sources, such as wetlands, agriculture, municipal waste sites and water facilities, and termite colonies, contains less carbon-13 than background levels.
Science Direct describes the study’s findings:
They found that between 2020 and 2022, the drastic increase in atmospheric methane was driven almost entirely by microbial sources. Since 2007, scientists have observed microbes playing a significant role in methane emissions, but their contribution has surged to over 90% starting in 2020.
“Some prior studies have suggested that human activities, especially fossil fuels, were the primary source of methane growth in recent years,” said Xin (Lindsay) Lan, a scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) at CU Boulder and NOAA. She leads the reporting on NOAA’s global greenhouse gas trends at the GML. “These studies failed to look at the isotope profile of methane, which could lead to a different conclusion and an incomplete picture of global methane emissions.”
The researchers have not determined whether the increase in microbial emissions stems from increased outgassing by wetlands, other natural sources, or emissions from agriculture and waste disposal, but emissions from oil and gas development have been ruled out as a source.
Source: Proceedings of the National Academy of Sciences; Science Direct
CO2 Saturation Refutes Temperature Forcing Fears
A study published in the peer-reviewed journal Applications in Engineering Science reinforces claims made in other research papers by prominent scientists that adding carbon dioxide, with levels where they presently are, should only minimally contribute to further warming, if at all, because of the saturation effect.
The paper, by three faculty members of the Institute of Optoelectronics at Poland’s Military University of Technology in Krakow, provides a literature review of research on the impact of anthropogenic increase in atmospheric CO2 concentration on Earth’s climate, combined with an independent analysis of the radiation absorption of potential carbon dioxide. The paper concludes that while the topic merits further study, the best estimate is that atmospheric CO2 has already reached a level beyond which additional emissions will have almost no ability to absorb solar radiation and contribute to warming.
There is little or no debate about whether there is an atmospheric saturation effect for CO2. CO2 absorbs solar radiation at a specific frequency band, and when 100 percent of that specific frequency band is reached, adding further CO2 results in no additional warming. The debate is over whether that frequency band has been reached or exceeded. According to this paper, the answer is a resounding yes.
Theory confirmed by laboratory experiments indicates CO2’s “saturation mass” is approximately 0.6 kg/m2.2. The current amount of CO2 in Earth’s atmosphere is already approximately 6 kg/m2—about ten times the saturation mass.
“This implies that additional CO2 emissions may have little to no further warming effect, as the gas has already absorbed nearly all the infrared radiation it can within its absorption spectrum,” Vigilant News writes in reporting on the study. The mainstream media have largely ignored the study’s findings.
“[T]he question arises as to whether the additionally emitted carbon dioxide into the atmosphere will absorb thermal radiation,” state the authors. This and earlier studies the scientists examined suggest the answer to that question is no: “This unequivocally suggests that the officially presented impact of anthropogenic CO2 increase on Earth’s climate is merely a hypothesis rather than a substantiated fact,” the scientists conclude.
The study’s results align with the work of prominent physicists such as, W. A. van Wijngaarden, Ph.D., of the Department of Physics and Astronomy at York University, Canada; Will Happer, Ph.D., of the Department of Physics at Princeton University; and Richard Lindzen, Ph.D., emeritus professor in the Department of Atmospheric and Planetary Sciences at the Massachusetts Institute of Technology, as well independent researchers such as Randall Carlson, among others. All have long argued the climate impact of CO2 has been overstated while its benefits, principally the greening of the Earth, are often ignored.
For instance, in July 2024, Lindzen and Happer testified before the Kentucky legislature as follows:
The physics of carbon dioxide is that CO2’s ability to warm the planet is determined by its ability to absorb heat, which decreases rapidly as CO2’s concentration in the atmosphere increases. This scientific fact about CO2 changes everything about the popular view of CO2 and climate change.
Carbon dioxide is now a weak greenhouse gas. At today’s CO2 concentration in the atmosphere of approximately 420 parts per million, additional amounts of CO2 have little ability to absorb heat and therefore it is now a weak greenhouse gas. Its ability to warm the planet at higher levels of CO2 is very small.
This also means that the common assumption that carbon dioxide is “the main driver of climate change” is scientifically false.
This study and the work of numerous other researchers show that if the science is settled it’s not settled in the way climate alarmists claim or would embrace. If this research is correct, rising CO2 emissions can at most have a negligible impact on temperatures, while having a huge, beneficial impact on plant life.
If CO2 isn’t behind the recent modest increases in temperature, one must search for other causes, and one has recently been suggested in a paper published in the journal Geomatics.
For that paper, researchers using satellite data and surface observations found a decrease in the Earth’s albedo combined with variations in solar irradiance “explain 100 percent of the global warming trend and 83 percent of the [global surface air temperature’s] interannual variability as documented by six satellite- and ground-based monitoring systems over the past 24 years.”
According to this paper, a decrease in the Earth’s albedo, a critical point ignored or misrepresented by the Intergovernmental Panel on Climate Change, has caused Earth to reflect less solar energy back into space and absorb more of it, accounting for the recent warming trend. Rising carbon dioxide concentrations have nothing to do with recent warming, according to this paper, which is consistent with the research indicating CO2 has reached or surpassed its radiation-effect saturation point.
Source: Vigilant News; Applications in Engineering Science; CO2 Coalition; Kentucky Legislature; Geomatics
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H. Sterling Burnett, Ph.D., is the Director of the Arthur B. Robinson Center on Climate and Environmental Policy and the managing editor of Environment & Climate News.
