How will climate novelty influence ecological forecasts? Using the Quaternary to assess future reliability

Area of Science:

• Paleontology
• Climate Science
• Ecology

Background:

• Future climates are projected to be novel compared to recent conditions.
• Climate novelty poses a significant challenge for ecological forecasting models that rely on past climate-species relationships.

Purpose of the Study:

• To quantify the magnitude and ecological significance of future climate novelty.
• To assess the impact of increasing climate novelty on the predictive skill of ecological forecasting models.

Main Methods:

• Comparing projected future climate novelty with novel climates from the past 21,000 years in North America.
• Using fossil pollen records from eastern North America to establish relationships between model performance and climate novelty.

Main Results:

• By the late 21st century, under a high emissions scenario (RCP 8.5), future climate novelty is comparable to or exceeds peak levels seen in the last 21,000 years.
• Ecological forecasting model accuracy is projected to decline as climate novelty increases.
• Models incorporating species co-occurrences may maintain higher predictive skill.

Conclusions:

• Future climate novelty presents substantial challenges for ecological forecasting.
• There is a need to explore strategies for improving model reliability, including using geological analogs and enhancing models with assemblage-level data.