Abrupt changes in Great Britain vegetation carbon projected under climate change

Area of Science:

• Ecology
• Climate Science
• Environmental Modeling

Background:

• Ecosystems are vulnerable to abrupt 'regime shifts' triggered by various factors.
• Large-scale shifts are predicted for tropical and high-latitude ecosystems under climate change.
• Limited high-resolution modeling exists for smaller-scale shifts in temperate ecosystems.

Purpose of the Study:

• To project future abrupt shifts in vegetation carbon within Great Britain's land surface using a high-resolution model.
• To analyze the combined effects of climate and CO2, and climate change alone.
• To assess the potential for early warning signals preceding these abrupt ecosystem changes.

Main Methods:

• Utilized a high-resolution land surface model for Great Britain under two climate change scenarios.
• Employed a novel algorithm to detect and classify abrupt shifts in model time series.
• Isolated the impacts of climate and CO2 from climate change alone to understand non-linear responses.

Main Results:

• Projected numerous climate-driven abrupt shifts in vegetation carbon across 0.5%-1.5% of Great Britain's land area.
• Identified that shifts involving increased vegetation carbon exhibit stronger early warning signals (autocorrelation and variance).
• Observed that 81% of abrupt increases in vegetation carbon showed increased autocorrelation, compared to 56% for decreases.

Conclusions:

• Temperate terrestrial ecosystems in Great Britain are susceptible to numerous abrupt shifts under climate change.
• Early warning signals, particularly for increasing vegetation carbon, are detectable beforehand.
• These findings underscore the potential for significant, non-linear ecosystem responses to climate change.