Simulating Cambrian Climate: The Significance of Atmospheric CO2 Concentration and Continental Position

• Main Author: Cutting, Grace
• Format: Text
• Language: unknown
• Published: Scholarship & Creative Works @ Digital UNC 2021
• Subjects: Atmospheric Sciences; Climate; Earth Sciences; Sea ice
• Online Access: https://digscholarship.unco.edu/urj/vol10/iss1/2; https://digscholarship.unco.edu/context/urj/article/1245/viewcontent/auto_convert.pdf; https://digscholarship.unco.edu/context/urj/article/1245/filename/0/type/additional/viewcontent/URJ_faculty_approval_form.pdf; https://digscholarship.unco.edu/context/urj/article/1245/filename/1/type/additional/viewcontent/URJ_Letter.docx

The Cambrian Period began approximately 541 million years ago, and is known for the “Cambrian Explosion”, a time when multicellular life began to rapidly diversify. There is natural historic evidence (isotopes, rock formations, and fossils) that suggests the Cambrian Period experienced a warm climate. However, there is also conflicting evidence that the Cambrian climate may have undergone freezing and thawing cycles, with ice possibly present near the equator. It is critical to understand how ecosystems were able to adapt to past climate changes, especially when analyzing the impacts of modern human activity on climate. Climate model simulations were run to explore the type of climate the Cambrian may have experienced, as well as the sensitivity of the climate to greenhouse gases and land-surface conditions. Based on the simulated annual and global average surface temperature, mean annual precipitation, and sea ice thickness in the climate model, ice formation would have been unlikely at the equator during the Cambrian, even during the winter season.