This demagoguery and alarmism and hysteria was again spread quickly by many of the usual climate change religion suspects (like e.g. the AAAS)!
When medieval superstition trumps science!
Some of this research seems to be speculative, e.g. "possible tree mortality" and other vague terms.
The climate demagogues try hard to link a 56 million years ago event to today's warming by stressing the "anthropogenic" cause of higher CO2 in the atmosphere. Let's not forget CO2 is only a minute trace gas in our time!
Notice also this study appears to be based on computer modeling not on hard facts. Has any third party validated these computer model scenarios? Computer models and their 100 year forecasts also play a major role in the propaganda of the global warming hoax/climate change religion.
Very strange, notice these climate demagogues don't tell what the approximate CO2 and methane concentration in the atmosphere was 56 million years ago. Either they don't know or it was so much higher than today that they better not disclose it or otherwise their demagoguery would be exposed immediately! What if it was not higher CO2 that caused the warming period 56 million years ago?
"Palaeontologists have reconstructed a 56-million-year-old forest, offering a sobering view of what happens in a period of rapid warming due to rapid increase in atmospheric carbon dioxide.
The Palaeocene-Eocene Thermal Maximum (PETM) came at the end of the Palaeocene epoch. Over this period, global average temperatures rose by 5–8°C over just a few thousand years.
This warming was triggered by a massive, rapid release of carbon dioxide and methane into the atmosphere and oceans primarily through volcanic activity which would have been intensified through feedback loops, including melting permafrost and large-scale wildfires.
Research published in the journal Science shows how the PETM impacted on an ancient forest fossilised in rocks in US state Wyoming and vegetation globally.
The team found reduced canopy cover and plant species migrating toward the poles. ..."
"“We are putting CO₂ into the atmosphere faster than any known natural process,” [???] says paleobotanist Dr. Regan Dunn, Assistant Deputy Director and Associate Curator of the Samuel Oschin Global Center for Ice Age Research at La Brea Tar Pits and the Natural History Museum of Los Angeles County. “The Earth has never experienced a carbon release at the pace we're creating today." ..."
"... This sudden warming event, called the Paleocene–Eocene Thermal Maximum (PETM), was one of the most notable climatic upheavals in Earth’s history. The volume of CO2 released [??? so how much was released?] during that period is thought [???] to be roughly equivalent to the total human emissions that would [???] be released by the end of the twenty-first century under a pessimistic scenario. The ancient surge of CO2 raised global average temperatures by between 5 and 9 °C, changing the climate for more than 150,000 years. ..."
"... Understanding how forest structure changed during the PETM is really important, because it tells us about how plant growth, biomass and productivity are affected by adding a lot of carbon dioxide [??? how much?] to the atmosphere,” Currano [Ellen Currano, senior author of the study] says. “It turns out that too much carbon dioxide is a bad thing for forests, because the accompanying warming and drying stresses the trees and kills many of them.” ..."
From the editor's summary and abstract (Notice, the abstract does not mention the CO2 concentration in the atmosphere):
"Editor’s summary
Predicting the effects of climate change depends on complex feedbacks between climate and vegetation. Although elevated carbon dioxide from anthropogenic emissions could make photosynthesis more efficient, leading to greater vegetation productivity and carbon storage, coincident warming and drought can reduce primary productivity. Dunn et al. examined how these factors interacted to influence forest productivity in another period with elevated carbon dioxide and 5° to 9°C of global warming, the Paleocene-Eocene Thermal Maximum, which occurred about 56 million years ago. Based on an analysis of leaf cuticles from fossils, the researchers found that there was elevated canopy opening early in this period, possibly due to tree mortality, which occurred along with major vegetation and hydrological changes. ...
Abstract
Uncertainty remains regarding the impact of rapid anthropogenic [???] warming on forest ecosystem structure, biodiversity, and function.
As an analog [???], we reconstruct forest canopy density and compositional change in Wyoming, USA, through the Paleocene-Eocene Thermal Maximum (PETM), an interval of abrupt carbon increase and warming ~56 million years ago. We develop a proxy to quantify leaf area index and assess shifts in floral composition using palynomorphs.
Forest canopies opened abruptly at onset of PETM warming, landscape erosion increased, and vegetation shifted from broad-leaved angiosperm to fern- and palm-dominated ecosystems.
When combined with regional data, these patterns suggest that continental-scale changes in plant communities cause landscape destabilization. These shifts also have implications for multimillennial-scale hydrologic and carbon cycle feedbacks in the climate system."
Fossil forest offers chilling window into climate change future | News | ConnectSci
(Left) Fisheye view of a forest canopy above a corresponding estimate of forest structure. (Top Right) Leaf cuticle collected from modern forest soil. (Bottom Right), Fossilised leaf cuticle from the Hanna Basin.
Satellite data shows a browning trend across the planet since around the turn of the century. [Demagogues like to use shocking photos like this]
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