Publication Date:
2021-12-15
Description:
New Zealand was among the last habitable places on earth to be colonized by humans1.
Charcoal records indicate that wildfires were rare prior to colonization and widespread
following the 13th- to 14th-century Māori settlement2, but the precise timing and
magnitude of associated biomass-burning emissions are unknown1,3, as are effects on
light-absorbing black carbon aerosol concentrations over the pristine Southern Ocean
and Antarctica4. Here we used an array of well-dated Antarctic ice-core records to show
that while black carbon deposition rates were stable over continental Antarctica during
the past two millennia, they were approximately threefold higher over the northern
Antarctic Peninsula during the past 700 years. Aerosol modelling5 demonstrates that
the observed deposition could result only from increased emissions poleward of
40° S—implicating fires in Tasmania, New Zealand and Patagonia—but only New
Zealand palaeofire records indicate coincident increases. Rapid deposition increases
started in 1297 (±30 s.d.) in the northern Antarctic Peninsula, consistent with the late
13th-century Māori settlement and New Zealand black carbon emissions of
36 (±21 2 s.d.) Gg y−1 during peak deposition in the 16th century. While charcoal and
pollen records suggest earlier, climate-modulated burning in Tasmania and southern
Patagonia6,7, deposition in Antarctica shows that black carbon emissions from burning
in New Zealand dwarfed other preindustrial emissions in these regions during the past
2,000 years, providing clear evidence of large-scale environmental effects associated
with early human activities across the remote Southern Hemisphere.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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