Deforestation Induced Climate Change: Effects of Spatial Scale

Area of Science:

• Climate science
• Ecology
• Earth system science

Background:

• Deforestation alters atmospheric CO2, surface energy, and mass balances, influencing climate.
• Previous models of large-scale deforestation suggest latitude-dependent surface air temperature (SAT) responses: cooling at high latitudes, warming at low latitudes, and mixed at mid-latitudes.

Purpose of the Study:

• To investigate the effects of varying deforestation fractions (5% to 100%) on climate.
• To examine SAT and soil moisture responses to deforestation across different latitudes.
• To determine the impact of deforestation on atmospheric CO2 and soil carbon dynamics.

Main Methods:

• Utilized a global climate model to simulate deforestation.
• Applied fractional deforestation scenarios (5% to 100%) in high, mid, and low latitude regions.
• Analyzed changes in surface air temperature, soil temperature, soil moisture, and net primary productivity.

Main Results:

• High latitude deforestation consistently reduced global mean SAT; low latitude deforestation increased it.
• Deforested areas generally became drier with lower SAT, though soil temperatures rose in mid and low latitudes.
• High latitude deforestation (≥45%) led to increased soil carbon and a net decrease in atmospheric CO2 due to enhanced net primary productivity and colder, drier conditions.

Conclusions:

• Deforestation's climate impact is complex and latitude-dependent.
• Fractional deforestation analysis refines understanding of SAT and hydrological cycle responses.
• Significant high latitude deforestation can potentially sequester atmospheric carbon, highlighting intricate land-atmosphere-carbon cycle interactions.