Periodic Reporting for period 2 - DECAF (Deforestation – Climate –Atmospheric composition – Fire interactions and feedbacks)
Reporting period: 2019-09-01 to 2021-02-28
Aim and objectives The primary aim of DECAF is to make a step change in our understanding of the impacts of deforestation on the Earth system through the interactions and feedbacks between tropical deforestation, fires, atmospheric composition and climate. DECAF is the first integrated study of the combined interactions and feedbacks between tropical deforestation, fire, atmospheric composition and climate. DECAF has the following objectives:
Objective 1) To understand the interactions between tropical land-use change and fire.
Objective 2) To quantify particulate emissions from tropical fires and make the first robust estimate of the impact of deforestation fires on air pollution.
Objective 3) To quantify the impacts of tropical deforestation on rainfall, accounting for both changes in land surface and atmospheric aerosol.
Objective 4) To explore the Earth System interactions associated with deforestation and deforestation fire.
To address this important challenge, DECAF will exploit new information from laboratory experiments, in-situ and satellite observations in combination with state-of-the-art numerical models.
Through Activity 2 Particulate emissions from tropical fires and impacts on air quality we have worked to constrain fire emissions and assess impacts on air quality (Butt et al., 2020) and the impacts of interventions to reduce fire and air quality impacts (Conibear et al., 2020). We estimate that the prevention of vegetation fires would have averted 16 800 (95UI: 16 300–17 400) premature deaths across South America. The health benefits of fire prevention in the Amazon are comparable to those found in Equatorial Asia. We quantified the impacts of a transition of household energy from solid fuel use to liquefied petroleum gas (LPG) on public health in India from ambient and household PM2.5 exposure. We estimate that the transition to LPG would reduce ambient PM2.5 concentrations by 25%. Reduced exposure to total PM2.5 results in a 29% reduction in the loss of healthy life, preventing 348 000 premature mortalities every year. Our work shows that a transition to clean household energy can substantially improve public health in India, however, these large public health benefits are dependent on the complete transition to clean fuels for all.
Through Activity 3 Impacts of deforestation on rainfall we have started to use remote sensing and models to assess the impacts of land-use change on rainfall and local and regional climate.
Through Activity 2 Particulate emissions from tropical fires and impacts on air quality we have combined remote sensing and atmospheric models to constrain fire emissions and assess impacts on air quality (Butt et al., 2020). This work has so far focused on the Amazon. We estimate that the prevention of vegetation fires would have averted 16 800 premature deaths across South America. The health benefits of fire prevention in the Amazon are comparable to those found in Equatorial Asia.
Through Activity 1 (Deforestation – Fire Interactions) we have developed new interdisciplinary approaches to assess the role of the selective logging on forest biomass in tropical forests. Our analysis combines field data, satellite remote sensing and participatory interviews (Ngo et al., 2020). Analysis of Landsat images over the period 1990 to 2014 combined with forest inventory data, demonstrates selective logging was leading to ongoing degradation of natural forests resulting in loss of 3.3 ± 0.8 Mg biomass ha−1 yr−1 across the protected area. We estimate that preventing illegal logging would incur local opportunity costs of USD $4.10 ± 0.90 per Mg CO2, similar to previous estimates for tropical forest protected areas and substantially less than the opportunity costs in timber or agricultural concessions.