4.5.3 Pandora’s Earth Systems Pyxis 

“Contrary to popular belief, but confirmed by repeated natural disasters that have taught us otherwise, humans have amazingly little control over Mother Nature”. Kieffer, 2013. 

Fire regimes are cyclical systems within systems, of which the configuration shifts in response to environmental change at broad local and global, seasonal and epochal scales. Studies of both paleo and present-day fire regimes have revealed a ‘Butterfly Effect’ [108] like chain of influence that extends from flora to climate. For example, fire- adapted species influence fire behaviour; fire behaviour influences cloud formation; cloud formation influences climate (Liu, 2005: NASA, 2017), which in turn, influences wildfires. The phenomenon has been observed in studies of the impact of wildfires on rain-cloud formation in wide-ranging regions, including Yellowstone National Park (Ibid), and Amazonia (Bevan et al, 2009). Findings from the former study linked the 1988 wildfires to a period of extended drought thereafter. Whereas, findings from the latter found rain-cloud formation had been delayed by a period of 15-30 days, thus extended the fire season. However, a further study established that not merely does wildfire smoke have capacity to extend the fire season, but to increase the formation of “positive cloud-to-ground lightning strikes” across distances of 2000>m (Bowman et al, 2011 citing Lyons et al, 1998), thus spark its own ignition. Therein lies another feedback chain: wildfires create smoke; smoke aerosols create cloud-to-ground lightning strikes; lightning strikes create wildfires; wildfires reduce rain-cloud formation, which in turn creates drought, which contributes to climate change, which Romps et al suggest (2014) creates more lightning strikes at a rate of 12±5% per/°C warming. The inter-relation of fire and drought is, likewise, evidenced in “many fire episodes” in the charcoal record (Odion et al, 2014), which also reveal rapid transition within fire regimes during periods of abrupt climatic change. Hence, while qualitatively distinct, the various fire regimes are not mutually exclusive entities, instead assemblages of species that reconfigure their distributions, populations, and inter-species dependencies in space and time. But, these are but a few of the items as are emerging from ‘Pandora’s Earth Systems pyxis’. 

As wildfires have capacity to worsen drought, vice versa. Drought both increases tree mortality, therein tinder-ready fuel (Abatzoglou and Williams, 2016), while exerting physiological stresses that have been found to reduce fire-resilience in several conifer and fir species (Young and Sullivan, 2013). However, drought not merely reduces flora’s resilience to fire, but to pests and pathogens, such as woodboring beetles, while increasing the probability of outbreaks thereof (Anderegg et al. (2015; Thorne et al, 2017). In turn, pests and pathogens cause yet further physiological stress to trees, therein increase their probability of mortality, thus becoming tinder-ready fuel. Where some see a vicious circle, others see a virtuous one. But, whether one ascribes to the philosophical concept of creative destruction, or otherwise, that such is the complexity of the systems of atmospheric and ecological systems as are to hand as to limit humanity’s capacity to exert control thereover. 

Evidence of the interplay between drought and wildfire can be found in publications and the landscape alike, and no less so than in California. Perusing articles archived from the summer of 2016, one finds the writing that 2017 would become one of the most notable wildfire seasons on record was on the digital wall: 

“Choked with the detritus of at least 70 million dead trees, vast tracts of the landscape have become a botanical emergency room, parched by drought, invaded by damaging insects and infected with a deadly organism” Cart, 2016, online. 

“Tree die-offs of this magnitude are unprecedented and increase the risk of catastrophic wildfires” Assoc. Press, 2016, online. 

“Like tens of millions of matchsticks, California’s dead trees are ready to burn” Craft, 2016, online. 

Adding to this anthropogenically ignited, but increasingly feedback-fuelled fire, smoke aerosols and climate change aren’t the only factors extending the duration of the fire season. As discussed earlier, human activity is likewise. 

The relationship between wildfires and climate change expresses yet another Pandorian loop: within fire-prone regions, increases to mean surface temperatures in turn increase the probability of wildfire; wildfires emit carbonaceous aerosol and black carbon [the most potent of the greenhouse gases]; increases in greenhouse gases increase climate change, and so the cycle continues. Hence, a paradox, for though many assume that forests constitute carbon sinks, they can, within fire-prone regions, “turn to sources” (McGuire, 2013), as has already occurred in several regions (Gramling, 2017). Bringing perspective to the order of magnitude of emissions as may result from wildfire activity in the years ahead, U.S. wildfires are estimated to emit 290 million metric tons of carbon dioxide p/y, the sum thereof approx. 4-6% of its total annual emissions (National Science Foundation, 2007). However, wildfires are but one of several sources of greenhouse gas emissions over which humans have not control, including methane emissions from microbial activity in warming soils (Melillo et al, 2017), and from gaseous emissions from melting permafrost (Knoblauch et al, 2018), and the Arctic seabed (Stranahan, 2008). Additionally, ‘wild’ fires are not the only carbon emissions source as relate to forests, for both in the U.S., where presently the sum thereof is unaccounted for, and in regions including Europe, virgin forests are being burnt on the premise that they provide ‘renewable’ fuel. As yet, such schema account not for the possibility that forests may turn from carbon sinks to sources, nor for the ecological inter-dependencies of species that migrate between forests located across broad spatiotemporal scales, let alone the medium to long-term implications thereof. 

Hence, this study and its recommendations align to a bandwidth of possible climate futures, as opposed to assuming that human action can limit mean surface temperatures to the <1.5°C increase recommended in the Paris Climate Agreement (European Commission, 2017), and the <2°C that has been cited as a benchmark more generally (Titley, 2017). A not insignificant number of Earth Systems scientists consider it more, not less probable that the scale and scope of feedback loops within the climate system could render such targets unachievable and headlines of the ilk of “Leaked U.N. climate report sees ‘very high risk’ the planet will warm beyond key limit” (Mooney, 2018), and “Global Warming’s Worst-Case Projections Look Increasingly Likely” (Temple, 2017) come as no surprise to some. “Difficult to predict”, the specificities of the spatiotemporal dimensions of ecological regime shifts, both as relate to fire and otherwise, may be (Seekell, 2016, p. 1109) the task is not necessarily “impossible”. 

>Continue to Chapter 4.5.4 here.

Footnotes

[108] In reference to Edward Lorenz’ Chaos Theory concept the Butterfly Effect (Gleick, 1998).

The thesis is also available in PDF format, downloadable in several parts on Academia and Researchgate.

Note that figures have been removed from the digital version hosted on this site, but are included in the PDFs available at the links above.

Citation: Sterry, M. L., (2018) Panarchistic Architecture: Building Wildland-Urban Interface Resilience to Wildfire through Design Thinking, Practice and Building Codes Modelled on Ecological Systems Theory. PhD Thesis, Advanced Virtual and Technological Architecture Research [AVATAR] group, University of Greenwich, London.