Large Variations in Southern Hemisphere Biomass Burning During the Last 650 Years

Abstract

We present a 650-year Antarctic ice core record of concentration and isotopic ratios (δ(13)C and δ(18)O) of atmospheric carbon monoxide. Concentrations decreased by ~25% (14 parts per billion by volume) from the mid-1300s to the 1600s then recovered completely by the late 1800s. δ(13)C and δ(18)O decreased by about 2 and 4 per mil (‰), respectively, from the mid-1300s to the 1600s then increased by about 2.5 and 4‰ by the late 1800s. These observations and isotope mass balance model results imply that large variations in the degree of biomass burning in the Southern Hemisphere occurred during the last 650 years, with a decrease by about 50% in the 1600s, an increase of about 100% by the late 1800s, and another decrease by about 70% from the late 1800s to present day.

Predictability of biomass burning in response to climate changes

“…However, regional scale analyses have consistently failed to show an association between human presence or activities and the amount of biomass burning as shown by charcoal records [Daniau et al, 2010a;Mooney et al, 2011;Marlon et al, 2012;Power et al, in press]. The pre-industrial charcoal record of the past 2000 yrs parallels northern hemisphere temperature changes as reconstructed from multiple high-resolution natural archives [Marlon et al, 2008] and this same pattern has been independently demonstrated for the more recent period , on the basis of stable isotope analyses of carbon monoxide in Antarctic ice [Wang et al, 2010; see also Prentice, 2010]. On a longer timescale, glacial periods have been characterized by less biomass burning globally than during warm intervals [Daniau et al, 2010b;Power et al, 2008].…”

“…The global incidence of fire decreased during the twentieth century [Marlon et al, 2008;Wang et al, 2010] despite increasing temperatures. This could have been a result of increasing (and increasingly efficient) fire management.…”

The status and challenge of global fire modelling

“…carbonyl sulfide, ammonium ion, black carbon, levoglucosan, vanillic acid) in polar ice cores (e.g. Wang et al, 2010Wang et al, , 2012Kawamura et al, 2012;Asaf et al, 2013;Petrenko et al, 2013;Zennaro et al, 2014). Both hemispherically integrated and spatially explicit records of past changes in fire will be used for model evaluation in FireMIP.…”

The impact of anthropogenic emissions on atmospheric sulfate production pathways, oxidants, and ice core Δ<sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)

“…As is done here, model studies typically assume that PI biomass burning was greatly reduced (10%) compared to to PD biomass burning and that the geographic distribution is unchanged. However, a recent study of the isotopic composition of CO from an Antarctic ice core suggests that there was more Southern Hemisphere biomass burning in the PI (1700-1850 CE) than the PD (1991 CE) (Wang et al, 2010).…”