Wildfires Mitigation Strategy and Incentives in Northern and Central Australia: Dr. Jeremy Russell-Smith

Transcription

1 30 August 13 th May 2015 Wildfires Mitigation Strategy and Incentives in Northern and Central Australia: Dr. Jeremy Russell-Smith Christopher Johns Research Analyst Northern Australia Research Programme Key Points The terms bushfire and wildfire are both used in Australia to describe uncontrolled, landscape fires in non-urban situations. Most Australians are concerned about the well-reported summer wildfires occurring in densely populated parts of south-eastern, southern and south-western Australia. The great majority of wildfires in Australia, however, occur annually in the northern savannas and less frequently in central Australia. Wildfires release a number of greenhouse gases into the atmosphere and the volume can be environmentally significant. Under international greenhouse gas (GHG) accounting rules, carbon dioxide (CO2) is not accounted for. An Australian study estimated that, if CO2 was accounted for, emissions from savanna alone would contribute over 35% of the total national GHG inventory. Context specific and place-based approaches, which take account of social and ecological considerations, are required to mitigate fire risk. Over the past fifteen years a substantial effort has been put into developing market-based, carbon methodologies which can reliably reduce GHG emissions from savanna late dry season wildfires. Market-based incentives have the potential to transform many of our fire management problems in the north creating new employment and enterprise opportunities.

2 Summary Australians are most concerned about the highly publicised wildfires that occur in the more densely populated, southern part of Australia. The very great majority of wildfires in Australia occur, however, in the northern savannas and less frequently in central Australia. These fires release significant volumes of greenhouse gases (GHG) into the atmosphere each year. Context specific and place-based approaches are required to mitigate fire risk and in the fire prone northern savannas and central rangelands the most effective means in these vast landscapes is to undertake prescribed burning in the cooler, early to mid, dry season months. Over the past fifteen years a substantial effort has been put into developing market-based, carbon methodologies which can reliably account for reducing GHG emissions from savanna late dry season wildfires. Such market-based incentives have the potential to transform many of our fire management problems in the north, creating new employment and enterprise opportunities on extensive fire-prone lands that otherwise have little or no economic pastoralism potential. Commentary FDI: What is the definition of wildfires and are they the same as bushfires? J R-S: Both terms are used in Australia to describe uncontrolled, landscape fires in nonurban situations. Perhaps wildfire has more of the sense of a serious out-of-control, threatening conflagration whereas bushfire can often refer to fires of lesser impact and severity, such as extensive understory fires which are annually common in the fire-prone savannas of northern Australia. FDI: What are the general features of wildfires in Australia in terms of frequency, season and area covered as well as their economic, environmental and social impact? J R-S: Most Australians are concerned about (because they are potentially affected by) wellreported summer wildfires occurring in densely populated parts of south-eastern, southern and south-western Australia. Wildfires in these regions are generally very infrequent at any one location (maybe occurring only once in many decades, if at all), small in size (from a few to hundreds of hectares), but can have very significant impacts on community safety, property and environmental values. Occasionally such fires extend over many thousands of hectares, and the horrendous summer fires of late 2002 to early 2003 in mostly forested areas of eastern VIC, ACT and southern NSW, burnt through possibly as much as 30,000 km 2 (half the size of Tasmania). Under catastrophic meteorological conditions (high winds and temperatures; low humidity), southern wildfires can occur as crown fires, literally exploding through forest canopies fuelled by volatile gasses produced by the ubiquitous eucalypts, and spotting kilometres in advance of the fire-front borne on flaming embers. Page 2 of 8

3 The very great majority of landscape fires ( bushfires ) in Australia, however, occur annually in the northern savannas (given reliable summer rains promoting grass growth), and less frequently (after good rain conditions) in central Australia. Fires in these regions are lit mostly by people although the incidence of lightning ignitions increases in more arid settings (given less likelihood of rain accompanying dry storms). In a typical year, around 400,000 km 2 (or 20% of Australia s northern savannas) is burnt mostly in the latter part of the 7 to 8 month (April-November) dry season period, under increasingly hot and dry conditions. Given very low population densities, little protective infrastructure (e.g. roads, tracks) and natural fire barriers (e.g. perennial rivers), individual fires can be enormous for example, fires have been known to start in western QLD and end up in WA, and to travel over 300 km in less than 36 hours! In the fire-prone north it is not unusual for such fires to go totally unreported in even the local media. By contrast with southern forest fires, those in the northern savanna and central rangelands are invariably ground fires, consuming grasses, leaf litter and shrubs but never travelling through the canopy. Although much less intense than southern infernos, the high frequency of especially late dry season, relatively severe fires in northern regions have been shown to have many significant negative impacts for example on conservation and pastoral (mostly beef cattle) production values; nutrients, soil erosion and stream sediment transport; tree biomass and carbon stocks; and emissions of greenhouse gases. The well-publicised cataclysmic decline in the central and northern Australian small mammal fauna is clearly linked to (but not totally caused by) unsustainable contemporary fire patterns. It is increasingly understood that current fire problems in the north and centre have emerged only over the past century or so, following breakdown of the extensive and systematic patch-burning practices undertaken formerly by Aboriginal people over millennia. Page 3 of 8

4 FDI: What role do wildfires play in relation to climate change and does climate change have an impact on wildfires? J R-S: Bushfires release a number of greenhouse gases which have lasting warming effects on the atmosphere. These include carbon dioxide (CO2), the major contributor, and smaller quantities of methane, nitrous oxide, volatile organic compounds, amongst others. The warming potential of these latter GHGs is much greater, molecule-for-molecule, than CO2. As would be expected, the size and intensity of the fire (i.e. the quantity of fuel consumed), directly influences the volume of GHGs emitted. Depending on the national extent of landscape fires in any one year, these typically contribute annually between 2 to 4% (equivalent to around 10 to 20 million tonnes of CO2) to Australia s national greenhouse inventory accounts. Most of this is contributed by savanna fires. A colleague, Dr Mick Meyer of CSIRO, estimates that the very extensive southern forest bushfires of (mentioned above), contributed about 30% of the national bushfire emissions for the inventory year. A key issue in the accounting of GHG emissions is that, under international GHG accounting rules, only emissions of methane and nitrous oxide, and not carbon dioxide, are accounted for. This is based on the assumption that the CO2 emitted is taken up in the regenerating vegetation in the next growing period. This assumption, however, does not account for the time lapse that the emitted CO2 contributes to atmospheric warming, nor does it account for general rundown in vegetation carbon stocks under recurring severe fires. One Australian study estimated that, if CO2 itself was allowed to be accounted for, GHG fire Page 4 of 8

5 emissions from savanna alone would contribute over 35% of the total national GHG inventory. Of considerable concern is that, under modelled climate projections for the remainder of this century, it is highly probable that worsening meteorological conditions (especially increased numbers of very hot days) in many fire-prone regions will exacerbate current wildfire problems resulting in increased GHG emissions. For example, it is predicted that the number of days annually that Darwin, as an example of a key savanna centre, experiences temperatures exceeding 35C, will rise from currently around 11 to 89 by FDI: What can be done to mitigate the negative impact of wildfires? J R-S: It is an observed fact that, as human populations and infrastructure development continues to expand around our urban centres, so too do the complexities of preparing for, responding to, and living with wildfire increase. No amount of post-fire Royal Commissions is going to extinguish (but hopefully diminish) the fire risk to communities living in the inherently fire-prone rural-urban interfaces of south-eastern, southern, and south-western Australia. That complexity is well described in a recent paper in the journal Nature, which makes the common sense point that context specific and place-based approaches (which take account of social and ecological considerations) are required to mitigate fire risk. In southern Australia there is typically a fair bit of controversy surrounding the concept of fuel hazard reduction burning that is, undertaking prescribed burning under safe meteorological conditions to reduce the risk of intense wildfires (e.g. to reduce the chance of fire spreading from ground fuels into canopies), especially in strategic locations (e.g. areas of greatest risk such as around urban centres). Probably the best exemplars of this practice in southern Australia are forest fire managers in south-west WA who, since the early 1960s, have undertaken a concerted program of fuel hazard reduction across 2.5 million hectares in a region containing 90% of the WA population. An authoritative account of that program, including its ecological basis, is given in a recent paper by Neil Burrows and Lachie McCaw. It is important to note, however, that fuel hazard reduction burning is not appropriate in many moist ( wet sclerophyll ) forest situation (these will burn only under extreme weather conditions in any event), and in various ecological contexts involving firesusceptible plants and animals. For the fire-prone northern savanna and central rangelands, following Aboriginal practice and contemporary experience the most effective means for addressing recurring fires in these vast landscapes is to undertake strategic prescribed burning in the cooler early to mid, dry season months. Relative to fires later in the season, fires lit at this time (under appropriate non-windy conditions) tend to be small, consume less fuel, are less severe, leave more unburnt patches, and all-round provide more sustainable ecological outcomes. However, implementing effective strategic prescribed burning in these vast landscapes (and typically involving very large properties) is logistically and economically challenging, to say the least. One developing approach, addressed in the next section, is to explore supportive opportunities through incentivised carbon markets for reducing GHG emissions. Page 5 of 8

6 Not all northern land managers, however, like or feel comfortable about using fire as a tool for mitigating wildfire. These include some small block owners in the urban-rural interface (who are prepared to take a risk that their 4 m wide firebreaks and other preparations will provide protection), but especially the large pastoral holdings on fertile soils supporting extensive highly productive grasslands for example, across the Gulf plains in northern QLD, the Barkly Tablelands and Victoria River District in the NT, parts of the Ord and Fitzroy River catchments in WA. These grassland situations are intensively managed and grazed and supported by substantial infrastructure (tracks, fences, water points). If prescribed fire management is undertaken at all in these situations, it is most likely to be used (using relatively intense fires) to help control woody thickening, or used in back-burning operations in the advent of a wildfire. FDI: Are there mitigation concepts being implemented or under consideration? If not, what needs to be done to start this process? J R-S: The social and ecological complexities of mitigation activities in southern Australian, particularly in the peri-urban environment, have already been alluded to above. More prospective are developing opportunities to assist land managers in the annually fire-prone north. Over the past fifteen years a substantial, practical research effort has been put into developing market-based, carbon methodologies which can reliably account for reducing GHG emissions from savanna late dry season wildfires. The original GHG emission abatement methodology, formally endorsed by the Australian Government in 2012 as part of its international climate change commitments, has recently been extended to include a non-living biomass (e.g. leaf litter, woody twigs, logs) carbon sequestration component, and work is ongoing to develop a living biomass sequestration methodology. Page 6 of 8

7 The essential principle of all these methodologies is that, through application of prescribed strategic fire management undertaken early in the dry season, reductions in GHG emissions (and associated enhanced carbon sequestration in biomass) can be measured against average emissions and sequestration achieved over a preceding 10-year baseline period prior to implementation of a fire management project. Each tonne of GHG emissions (measured as CO2 equivalent) that is abated or sequestered yields 1 carbon credit worth around $15 as of April Much of the preliminary research work was undertaken in association with a large landscape-scale fire management endeavour operating in Aboriginal-owned Arnhem Land, the West Arnhem Fire Abatement (WALFA) project. Since the commencement of the WALFA project in 2005, WALFA fire managers have achieved an annual average reduction in accountable GHG emissions (only methane and nitrous oxide, as described above) of around 40% (or around 130,000 tonnes of CO2 equivalent). This has entailed reducing the overall annual extent of burning in WALFA (from around 40% to 35% of the entire 28,000 km2 project area), but particularly reducing the average extent of late season wildfires (from 32% originally to 11% currently). Since 2005, the WALFA program has operated under a voluntary agreement with a multinational energy corporate, to offset GHG emissions from its liquefied natural gas plant in Darwin Harbour. Over the past few years the Australian Government has introduced formal market-based GHG emissions reduction programs, the Carbon Farming Initiative (CFI) and, more recently, the Emissions Reduction Fund (ERF). As of early 2015, there were 34 CFIregistered savanna burning emissions abatement projects (including WALFA) operating across northern Australia. It is entirely feasible that market-based savanna burning projects will be taken up across much of the fire-prone north given that they can be undertaken on all tenure types. Such market-based incentives have the potential to transform many of our fire management problems in the north in fact, creating new employment and enterprise opportunities on extensive fire-prone lands which otherwise have little or no economic pastoralism potential. Although similar prescribed fire management approaches would potentially work (and be highly beneficial) in central Australia, preliminary assessment suggests that the scale of prescribed burning required to achieve carbon abatement outcomes is logistically (and economically) prohibitive. Likewise, detailed assessment of the practicability of applying similar emissions mitigation approaches in southern Australian forested situations has indicated that prescribed burning is unlikely to yield a net reduction in emissions, and high frequency burning programs could in fact result in an increase in emissions and a potential reduction in overall carbon stored. ***** Page 7 of 8

8 About the Interviewee: Dr. Jeremy Russell-Smith, Adjunct Professor at Charles Darwin University, is an ecologist with particular interests in helping to achieve sustainable management outcomes in fire-prone savanna landscapes across northern Australia and nearby countries. He helps coordinate the applied research program of the Darwin Centre for Bushfire Research at Charles Darwin University, in partnership with a large variety of community, sectoral, agency, and research organisations. ***** Any opinions or views expressed in this paper are those of the individual interviewee, unless stated to be those of Future Directions International. Published by Future Directions International Pty Ltd. 80 Birdwood Parade, Dalkeith WA 6009, Australia. Tel: Fax: info@futuredirections.org.au Web: Page 8 of 8