Impact of human population density on fire frequency at the global scale
Human impact on wildfires, a major earth system component, remains poorly understood. While local studies have found more fires close to settlements and roads, assimilated charcoal records and analyses of regional fire patterns from remote-sensing observations point to a decline in fire freq...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-02-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/11/1085/2014/bg-11-1085-2014.pdf |
| Summary: | Human impact on wildfires, a major earth system component, remains
poorly understood. While local studies have found more fires close
to settlements and roads, assimilated charcoal records and analyses
of regional fire patterns from remote-sensing observations point to
a decline in fire frequency with increasing human population. Here,
we present a global analysis using three multi-year satellite-based
burned-area products combined with a parameter estimation and
uncertainty analysis with a non-linear model. We show that at the
global scale, the impact of increasing population density is mainly
to reduce fire frequency. Only for areas with up to 0.1 people
per km<sup>2</sup>, we find that fire frequency increases by 10 to
20% relative to its value at no population. The results are
robust against choice of burned-area data set, and indicate that at
only very few places on earth, fire frequency is limited by human
ignitions. Applying the results to historical population estimates
results in a moderate but accelerating decline of global burned area
by around 14% since 1800, with most of the decline since 1950. |
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| ISSN: | 1726-4170 1726-4189 |