Estimating present and future wildfire pollution in the U.S.

Transcription

1 Estimating present and future wildfire pollution in the U.S. (and a bit about the 2015 haze in Indonesia) Shannon N. Koplitz and Christopher G. Nolte USEPA/ORD/NERL/SED/EFAB In support of the Air Climate and Energy Program

2 Wildfire pollution is a global issue Average deaths per year attributed to fires during Johnston et al., 2012 Fire-related pollution leads to thousands of premature deaths every year. 2

3 Wildfire pollution is a global issue Average deaths per year attributed to fires during Johnston et al., 2012 Fire-related pollution leads to thousands of premature deaths every year. 3

4 Expanding agricultural concessions have noticeably altered the natural landscape in Indonesia since the 1980s Land use in peat forests as of 2010 Miettenen et al., 2012 Hoekman 2009 Timber Drainage canals in Kalimantan Burning timber concession Oil palm Peat Photo credit: Adek Berry / AFP / Getty Images (accessed from Human activity has dramatically increased the vulnerability of coastal peat swamps to fire. 4

5 Annual agricultural burning in Indonesia can be exacerbated by background meteorological conditions Normal El Nino Southern Oscillation Indonesia wet California El Nino Australian Bureau of Meteorology dry IPCC AR5 Source: IPCC AR5 Both El Nino and positive phases of the Indian Ocean Dipole lead to drought and amplified fire activity in Indonesia e.g. 1997, 2006 and

6 The Harvard-Columbia SMOKE rapid assessment framework Fire emissions (OC+BC) Archived sensitivities for of receptor PM 2.5 to fire locations from the GEOS-Chem adjoint quickly produces population-weighted PM 2.5 estimates and quantifies source region contributions Kim et al., 2015; Marlier et al., 2015; Koplitz et al., 2016 Health impact assessment 6

7 The 2015 haze in Indonesia is estimated to have led to more than 100,000 PM-related premature deaths Jambi S. Sumatra W. Kalimantan C. Kalimantan Koplitz et al., ERL 2016 Most of the smoke pollution leading to degraded regional air quality in 2015 was attributed to fire emissions in South Sumatra province. 7

8 Fires in the U.S. a complex landscape California 2013 Tennessee 2016 Photo: Dan Bartletti, Los Angeles Times (accessed from Colorado 2012 Photo: Saul Young/New Sentinel Texas 2017 Photo: Hoover Volunteer Fire Department (accessed from CNN.com) (accessed from Fires can account for more than 30%* of total U.S. PM 2.5 emissions. * Based on NEI

9 Project Goals 1. Characterize the implications of uncertainties in existing fire emission estimates for quantifying present day fire-related pollution in the U.S. 2. Estimate the influence of climate-driven changes in fire activity on future air quality and associated human health impacts. 9

10 Project Goals 1. Characterize the implications of uncertainties in existing fire emission estimates for quantifying present day fire-related pollution in the U.S. 2. Estimate the influence of climate-driven changes in fire activity on future air quality and associated human health impacts. 10

11 Fire emissions in global and regional models are estimated from four key variables. To estimate emissions E of chemical species s in grid cell i,j: E s,i,j = BA i,j x FL i,j x CC i,j x EF s Burned area Fuel load (i.e. how much biomass is there) Combustion completeness (i.e. how much of the available biomass actually burns) Emission factor per unit carbon combusted Burned area is usually quantified independently of the other three parameters, and can be estimated a variety of ways. 11

12 Burned area estimates agree reasonably well in the western U.S. NIFC MTBS NEI FINN GFED FINN is consistently lower than other estimates during high fire years in the Southwest, but agrees well with other inventories in the Northwest. 12

13 In contrast, estimates for the southern U.S. vary widely. NEI FINN NIFC GFED MTBS Prescribed burns, the dominant fire type across much of the southern U.S., tend to be smaller and shorter in duration than wildfires, and therefore harder to detect via remote methods. 13

14 What are the implications for modeling fire-related pollution and its impacts over the U.S.? Tasks 1. Run 4 1-year CMAQ 36km CONUS simulations*: a) without fire b) with NEI fire c) with GFED4s fire d) with FINN fire *Simulations will use 2011 meteorology (NEI inventory year and highest fire year in ). Emissions from other sectors will be the same across simulations. 2. Quantify changes in smoke PM and ozone attributed to the use of each inventory. 14

15 Modeled surface PM 2.5 from fires during March 2011 w/ NEI w/ FINN µg m -3 NEI FINN µg m -3 15

16 Next Steps 1. Estimate associated health impacts using BENMAP. 2. Apply source apportionment tools such as CMAQ Direct Decoupled Method (DDM) to identify geographic areas and/or fire types (e.g. wildfire vs. prescribed) where implementation of fire control strategies would most effectively reduce regional and national air quality impacts. 16

17 Extra Slides 17

18 Project Goals 1. Characterize the implications of uncertainties in existing fire emission estimates for quantifying present day fire-related pollution in the U.S. 2. Estimate the influence of climate-driven changes in fire activity on future air quality and associated human health impacts. PM in a Changing World - April

19 Most process-based land cover change models were not designed to reproduce fire activity at timescales relevant for air quality. NEI NIFC MC2 MC2 results courtesy of John Kim, USFS How can we best represent the influence of future land cover and future meteorology on fire activity in one approach? PM in a Changing World - April

20 Estimating present and future wildfire pollution in the U.S. (and a bit about the 2015 haze in Indonesia) Nassau County Florida March Photo Credit: Shannon N. Koplitz and Christopher G. Nolte USEPA/ORD/NERL/SED/EFAB In support of the Air Climate and Energy Program

21 Burned area estimation methods include top-down and bottom-up approaches. Inventory Method to estimate burned area Global Fire Emissions Database (GFED) Fire Inventory from NCAR (FINN) Monitoring Trends in Burn Severity (MTBS) National Interagency Fire Center (NIFC) National Emission Inventory (NEI) Satellite-derived burn scars (MODIS) Satellite-derived active fire detections (MODIS) combined with fixed burned area by land cover type Satellite image processing (LANDSAT) Fire incident reports (federal and state data) NOAA Hazard Mapping System (includes active fires from MODIS, AVHRR, GOES), perimeters from MTBS, incident reports Table modified from Larkin et al Different approaches lead to significant variability in space and time between burned area estimates. 21

22 Future fires will be influenced by changes in both climate and human activity Climate-driven biomass combustion Percent of wildfires started by humans ( ) Present day Yue et al., Balch et al., 2017 Most previous estimates of future climate change-related air quality have excluded changes in wildfire pollution. 22

23 Estimating fire-related PM is one of the biggest challenges for future air quality projections No changes in wildfire activity Climate Change Impacts and Risk Assessment (CIRA) Report USEPA, 2015 PM in a Changing World - April

24 Differences in burned area estimates lead to substantial differences in the magnitude and distribution of fire emissions across inventories. Annual Total PM 2.5 Emissions for CONUS Larkin et al., 2014 ~8x more PM 2.5 emissions in NEI vs. GFED3 for 2011 What are the implications for modeling fire-related pollution and its impacts over the U.S.? 24

25 Estimates of annual total burned area across the U.S. can vary by more than a factor of 2 between inventories. The degree of variability across inventories differs by region within the U.S. 25

26 Fire regimes vary widely across the U.S. LANDFIRE Fire Regime Groups (USFS, DOI) PM in a Changing World - April

27 Fire activity is influenced by a combination of land cover and meteorology Fuel characteristics (monthly/yearly/decadal) Weather conditions (daily/hourly) Capturing both the land cover dynamics and the changes in weather patterns that are relevant for fire activity in one model is extremely difficult. PM in a Changing World - April

28 Next Steps 1. Refine approach for estimating future fire emissions in the U.S. 2. Use CMAQ to simulate changes in future PM and ozone pollution from climate-driven fire activity PM in a Changing World - April