Posted on 14/09/2011
Wildfires are often viewed as major disasters, and there is concern that climate change will increase their incidence. However, it is difficult to consider the true impact of past or future wildfires without understanding their place in natural and human history.
Many economically damaging fires are caused by people, such as in the case of the recent summer riots, yet fire is also an essential part of many ecosystems in many parts of the world. In some areas, people routinely manage fire to achieve a variety of outcomes in forest, game and land management, such as Dartmoor where fire was the main method of clearing land and creating pasture.
A team of 18 international researchers, including Professor Andrew C Scott from the Department of Earth Sciences at Royal Holloway, University of London have identified ways of helping others distinguish between the fires that should be considered natural disasters and those that are beneficial.
In a paper in the Journal of Biogeography published today (14 September 2011) the researchers, working at the National Centre for Ecological Analysis and Synthesis (NCEAS) at the University of Santa Barbara, offer an historical framework to help other researchers and managers develop a context for considering the relationships humans have with fire. Professor David Bowman of the School of Plant Science at the University of Tasmania, the lead author of this study, argues that this framework is key to planning for future fire risk and understanding the role of fire in natural ecosystems.
The value of the study is that it presents a critical assessment of the diversity of human uses of fire, from tamed landscape fire, agricultural fire and industrial fire. Dr. Jennifer Balch, Postdoctoral Associate at NCEAS, one of the authors of the paper, says: “Human use and misuse of fire has been so prevalent in our evolutionary history, and the evolution of cultures, that we’ve forgotten how dominant a force fire really is.”
The researchers’ analysis recognises four ‘fire phases’: Natural fires that occur regardless of humans; Tame fire used by hunter-gatherers to manage landscapes for game and wild food production; Agricultural fire used to clear land, grow food and burn fallow; and Industrial fire to power modern societies, that have switched from using living to fossilized plants as the primary fuel. The researchers explain that this remarkable diversity of human uses of fire, albeit imperfectly controlled, has powered all cultures. However, the problem is that the excessive combustion of fossil fuels is driving climate change. As explained by Balch: “Our fossil-fuel dependent economy is yet another extension of our dependence on combustion. We have effectively put fire in a box. The result of massive dependence on this one use of fire may ultimately overwhelm human capacities to control landscape fire, given more extreme fire weather and more production of fuels.”
Considering Earth’s fire history before human influence also offers great insights into the flammable planet we have inherited. Another of the paper’s authors, Professor Scott, from Royal Holloway, says: “Unravelling the nature of fire before any human influence is an important element of the current debate. Some only see fires in terms of human causation and impact. Understanding the ways that humans have and are altering natural wildfire systems has profound political and economic significance.”
The research highlights that understanding the relative influences of climate, human ignition sources, and cultural practices in particular environments is critical to craft sustainable fire management to protect human health, property, ecosystems, and greenhouse gas pollution.