Summary

Three main factors lead to severe haze over Equatorial Asia, such as in 1997, 2006, and 2015:

1. Meteorology: Drought-like conditions in Indonesia coincide with El Niño and positive Indian Ocean Dipole climatic phases
2. Fires: Burning is associated with land clearance and agricultural maintenance practices; degraded lands are also highly susceptible to ignition and spread of fire
3. Peatlands: Fires burrow underground in carbon-rich peatlands and smolder for days to weeks; peat fires are extremely difficult to extinguish

Although thick haze blankets Equatorial Asia in El Niño-induced drought years, fires recur every year in Indonesia. Fine particles in smoke from fire can penetrate deep into the human lungs, leading to increased risk of cardiovascular and respiratory diseases. We quantify the fire-related premature mortality by modeling PM2.5, or particulate matter less than 2.5 microns in diameter. "Premature mortality" is excess deaths that occur throughout the year after the fires but would not have occurred otherwise.

1. We estimate on average 36,000 premature deaths per year in Indonesia, Malaysia, and Singapore from 2020-2029 if no comprehensive land management strategies are undertaken to reduce fire activity
2. The majority of premature deaths — about two-thirds — are avoidable with maximum peatland restoration activities
3. We created the SMOKE Policy Tool that allows stakeholders to explore how various land management strategies can reduce premature mortality from fires
   • We created the SMOKE Policy Tool using Google Earth Engine and Earth Engine Apps
4. Top priority sites for the Indonesian Peatland Restoration Agency (BRG) to target are sites along the eastern coast of South Sumatra, as well as the southern coast of Kalimantan

Paper: Marlier et al. (2019, GeoHealth)

1. Marlier, M.E., T. Liu, K. Yu, J.J. Buonocore, S.N. Koplitz, R.S. DeFries, L.J. Mickley, D.J. Jacob, J. Schwartz, B.S. Wardhana, and S.S. Myers (2019). Fires, Smoke Exposure, and Public Health: An Integrative Framework to Maximize Health Benefits from Peatland Restoration. GeoHealth, 3, 178-189. https://doi.org/10.1029/2019GH000191
2. Koplitz, S.N., L.J. Mickley, M.E. Marlier, J.J. Buonocore, P.S. Kim, T. Liu, M.P. Sulprizio, R.S. DeFries, D.J. Jacob, J. Schwartz, and S.S. Myers (2016). Public health impacts of the severe haze in Equatorial Asia in September–October 2015: demonstration of a new framework for informing fire management strategies to reduce downwind smoke exposure. Environ. Res. Lett. 11(9), 094023. https://doi.org/10.1088/1748-9326/11/9/094023
3. Kim, P.S., D.J. Jacob, L.J. Mickley, S.N. Koplitz, M.E. Marlier, R.S. DeFries, S.S. Myers, B.N. Chew, and Y.H. Mao (2015). Sensitivity of population smoke exposure to fire locations in Equatorial Asia. Atmos. Environ. 102, 11-17. https://doi.org/10.1016/j.atmosenv.2014.09.045
4. van der Werf, G.R., J.T. Randerson, L. Giglio, T.T. van Leeuwen, Y. Chen, B.M. Rogers, M. Mu, M.J.E. van Marle, D.C. Morton, G.J. Collatz, R.J. Yokelson, and P.S. Kasibhatla (2017). Global fire emissions estimates during 1997-2016. Earth Syst. Sci. Data 9, 697–720. https://doi.org/10.5194/essd-9-697-2017