Savanna burning in a climate changed economy North Australia’s contributions to national adaptation and mitigation eff

1. Savanna burning in a climate changed economyNorth Australia’s contributions to national adaptation and mitigation efforts Lindsay Hutley (CDU) Jeremy Russell-Smith (NTG)

2. Talk outline • What and where are the savannas? • Climate change impacts on this ecosystem • Savanna burning as a mitigation activity – the WALFA program • Partial and full carbon accounting – the carbon economy

3. Savannas across north Australia • Tree-grass mixtures: competitive co-exisitance

4. Savannas across north Australia

5. Savannas burn every year • Dry season - highly flammable landscape • Fire emits GHGs  CO2, methane, N20 Photo Sam Setterfield

6. Savanna burning – 2011 fire scars

7. Savanna burning • 1-3% of national GHG emissions, 35-50% of NT emissions • Impact of climate change on savanna burning?

8. Climate trends – rainfall 2010/2011 Wet Top End 3000-1700 mm Centre 400-600 mm

9. Climate change and savanna landscapes • How will climate change affect these landscapes? • Savanna structure and productivity shaped by climate and fire interactions • Reduce or increase productivity (sink)? Or no change? CO2

10. Savanna fire risk • Living with climate change • Hotter, wetter wet, more CO2 productivity may increase = increased fuel • Hotter dry season = fire risk enhanced • Invasive grasses across mesic savanna adds to risk • GHG mitigation via fire management • manage fire differently to reduce greenhouse gas emissions • Case study – Western Arnhemland Fire Abatement Scheme (WALFA) • Experiment in landscape scale fire management

11. WALFA – GHG abatement scheme • Savanna GHG emission likely to increase • Fire regime change over time • de-population of many Aboriginal lands • lack of resources to manage vast landscapes • late dry season high severity / high impact fires more prevalent • biodiversity loss • Solution  WALFA?

12. Fire scars May 1999 WALFA area

13. Fire scars end November 1999

14. Co-occurrence of restricted range and endemic species Woinarski et al. 2005, 2009

15. WALFA – savanna fire abatement scheme • Western Arnhemland region chosen – 25 000 km2 • Significant biodiversity hot spot • Significant fire problem • Unique partnership between traditional owners, NT and Commonwealth Governments and private funders • Aims • Shift fire regimes at landscape scales • Reintroduce traditional burning regime, increase early dry season fires and patchiness • Accurately quantify savanna GHG emission factors • Develop remote sensing techniques to map fires and calculate emissions

21. WALFA – savanna fire abatement scheme Accountable emissions of non-CO2gases 2004-2010

22. Top End 2011 Fire scars

23. (b) GHG Emissions Pre-project baseline • WALFA • program • Seasonality of burning

24. Five Projects Across Northern Australia Potential for ~0.5 Mt CO2-e y-1 abatement

25. Savanna burning and fire abatement • But there’s more ... • WALFA partial carbon accounting • only non-CO2 gases emitted accountable under IPCC rules • Full carbon accounting • Account for all components of the GHG balance • Sequestration in vegetation and soil - CO2 uptake and loss • Shift in fire regime to EDS mosaics will enhance tree productivity and carbon sink • Soil carbon ??

26. CH4 N2O CH4 N2O WALFA - Non-CO2savanna GHG fluxes

27. CO2 CO2 Rleaf Fos Rwood Rsom Rroot Fus C Savanna carbon balance – full carbon accounting CO2 Soil carbon Above and below ground biomass pools GPP, NPP, NEP, NBP

28. Investigate savanna fire cycle on mass and energy exchange

29. Enhanced savanna ‘fire sink’ • For lowland savanna of WALFA area • Known area of 12984 km2 • For savanna • carbon sink small and sensitive to fire regime • assume sink is low, ~0.1 t C ha-1 y-1 • Sequestration with EDS mosaic – 0.48 Mt CO2-e y-1 • Emissions abatement with EDS mosaic – 0.15Mt CO2-e y-1 • WALFA sequestration under current rules not accountable • Difficult to quantify over space and time

30. Conclusions • Climate change likely to promote flammability • WALFA program has reduced emissions by 50% of managed area • Savanna fire return time (1-3 y) means an emissions saving every year is achievable • Other benefits • Income stream for remote Aboriginal custodians • Transform social and biodiversity landscape • Likely to enhance carbon sink as an ecosystem service • Developed methodology to be included in Carbon Farming Initiative • A 1 or 2%+ emissions reduction may be nationally significant

31. Questions