Understanding Carbon Dioxide Trends: New Insights from Science
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Chapter 1: Historical CO2 Concentrations
Recent research challenges the long-held belief that carbon dioxide levels in the atmosphere saw a dramatic decline in 1610. Instead, evidence suggests a gradual decrease over the span of 150 years. This period, from 1454 to 1688, coincides with the colonization of the Americas. As Indigenous lands transitioned from cultivation to abandonment, forests reclaimed these areas, absorbing approximately 260 million tons of carbon annually, as indicated by findings published in Nature Communications based on new Skytrain ice core data.
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Section 1.1: Ice Core Evidence
Air bubbles trapped within Antarctic ice serve as a vital resource for understanding carbon dioxide levels over the last two millennia. Notably, only two cores, Law Dome and WAIS Divide, provide continuous, high-quality records for this timeframe. A significant discrepancy arises around 1610 AD; while the Law Dome core shows a sharp reduction in CO2 levels known as the Orbis Spike, the WAIS Divide core does not reflect this decline.
Subsection 1.1.1: The Anthropocene Proposal
Researchers attribute the difference in findings to the interactions between the Old and New Worlds, suggesting that 1610 marks the onset of the Anthropocene. The observed decrease of 10 parts per million (ppm) in carbon dioxide over 90 years is believed to stem from a decline in the Indigenous population, which allowed for a robust regrowth of forests that absorbed atmospheric carbon. Establishing an accurate historical context is essential for enhancing current climate and carbon cycle models, necessitating new cores with reliable records.
Section 1.2: The Skytrain Core Findings
Led by Amy King from the British Antarctic Survey, a paleoclimate study of the newly collected Skytrain core, drilled in western Antarctica between 2018 and 2019, assessed carbon dioxide and methane concentrations at depths of 83.2 to 104 meters, covering the years 1454 to 1688. This analysis revealed that unlike the Law Dome core, the Skytrain core did not show a steep decline in CO2 levels around 1610. Instead, it indicated a gradual decrease of about eight ppm over 157 years, averaging approximately 0.5 ppm per year.
Chapter 2: Implications for Climate Models
The first video titled "The Science of CO2: Debunking the Saturation Myth" explores misconceptions surrounding carbon dioxide's role in climate change, providing a deeper understanding of its impact.
The authors concluded that the abrupt decline reported in the Law Dome core likely represents an artifact. If it accurately reflected true CO2 levels, terrestrial ecosystems would need to absorb up to a billion tons of carbon each year, an estimate that contradicts even the most extreme scenarios of forest recovery post-Indigenous settlement. The gradual decline recorded by the Skytrain core suggests a more realistic annual carbon uptake of 260 million tons, aligning with the historical context of land abandonment and subsequent forest regrowth following colonization.
The second video titled "World In Midst of Carbon Drought (w/ Prof. William Happer, Princeton University)" discusses the current state of carbon levels and their implications for climate policy and environmental science.
Additionally, ancient trees play a crucial role in reconstructing past climates. Recent studies analyzing the growth rings of pine trees in Fennoscandia over the last 1,170 years indicate that the medieval climate optimum, which peaked between 850 and 1100 AD, did not surpass the levels of contemporary warming.