Chapter 19
Correlation of Significant Voyaging Activity
with Rare Extreme Climate Events
Abstract Two climatic factors stand out as relevant to the maritime expansions
involved in the later west–east exploration and colonization of the southern Pacific:
global warmth for protection against hypothermia and strong El Niño Southern
Oscillation (ENSO) events capable of reversing the direction of the trade winds
and currents. The major impact of ENSO events in tropical Polynesia during the
Medieval Climatic Optimum, however, was more in precipitating than in supporting
migrations. In tropical Polynesia after c. AD 900, El Niño events brought in their
wake droughts, famine and conflict over land and resources, triggering migrations
for the starving and defeated. The pattern of strong to severe El Niños in the two
global warm periods covered by the low Nile flood proxy data reflects pulses of
exploration and migration within tropical Polynesia. It also reflects the pattern of
drought-driven migration from Eastern Polynesia to New Zealand that took place
in the Medieval Climatic Optimum. In both periods El Niño low Nile proxy data
suggests an associated chronology. We have chosen, as a focus for establishing this
chronology, Polynesian genealogies associated with a line of navigators and explorers, some of whose exploits are recorded in tradition and can be linked to and tested
against an El Niño-based chronology.
Keywords El Niño-driven migration · Nile proxy data · Extreme climatic
events · Drought and famine · Pulses of exploration and migration · Dating
migrations · Dating exploration
19.1 Introduction
H.H. Lamb presents a paradigm of worldwide, age-old, climate-driven movements
of peoples on the Earth. He speaks, for example, of the impact on human history
of the temperatures and moisture regimes of the Post-glacial Climate Optimum
(6000–3000 BC) when no insuperable desert barriers prevented the vast dispersal
of Indo-Europeans over Europe and southwest Asia and parts of India, possibly
from a homeland in the Caucasus region. The vastness of this dispersal, Lamb
sees as leading to the separate developments of the European language groups, but
325
C.E.M. Pearce, F.M. Pearce, Oceanic Migration,
DOI 10.1007/978-90-481-3826-5_19, C
Springer Science+Business Media B.V. 2010
Correlation of Significant Voyaging Activity
with Rare Extreme Climate Events
Abstract Two climatic factors stand out as relevant to the maritime expansions
involved in the later west–east exploration and colonization of the southern Pacific:
global warmth for protection against hypothermia and strong El Niño Southern
Oscillation (ENSO) events capable of reversing the direction of the trade winds
and currents. The major impact of ENSO events in tropical Polynesia during the
Medieval Climatic Optimum, however, was more in precipitating than in supporting
migrations. In tropical Polynesia after c. AD 900, El Niño events brought in their
wake droughts, famine and conflict over land and resources, triggering migrations
for the starving and defeated. The pattern of strong to severe El Niños in the two
global warm periods covered by the low Nile flood proxy data reflects pulses of
exploration and migration within tropical Polynesia. It also reflects the pattern of
drought-driven migration from Eastern Polynesia to New Zealand that took place
in the Medieval Climatic Optimum. In both periods El Niño low Nile proxy data
suggests an associated chronology. We have chosen, as a focus for establishing this
chronology, Polynesian genealogies associated with a line of navigators and explorers, some of whose exploits are recorded in tradition and can be linked to and tested
against an El Niño-based chronology.
Keywords El Niño-driven migration · Nile proxy data · Extreme climatic
events · Drought and famine · Pulses of exploration and migration · Dating
migrations · Dating exploration
19.1 Introduction
H.H. Lamb presents a paradigm of worldwide, age-old, climate-driven movements
of peoples on the Earth. He speaks, for example, of the impact on human history
of the temperatures and moisture regimes of the Post-glacial Climate Optimum
(6000–3000 BC) when no insuperable desert barriers prevented the vast dispersal
of Indo-Europeans over Europe and southwest Asia and parts of India, possibly
from a homeland in the Caucasus region. The vastness of this dispersal, Lamb
sees as leading to the separate developments of the European language groups, but
325
C.E.M. Pearce, F.M. Pearce, Oceanic Migration,
DOI 10.1007/978-90-481-3826-5_19, C
Springer Science+Business Media B.V. 2010