Patrick D. Nunn

Environmental catastrophe in the Pacific Islands around A.D. 1300

Paleosea-level data for the Pacific Islands suggest that sea level in the region fell, possibly in two stages, between 680 and 475 cal yr B.P. (A.D. 1270–1475). This was associated with a ∼1.5°C fall in temperature (determined from oxygen-isotope analysis) and an observed increase in El Nino frequency. For a long time, it has been clear that these changes—characterized as the “A.D. 1300 event”—brought about environmental and cultural changes on Pacific Islands. These are documented here systematically for the first time. Temperature fall, sea-level fall, and possibly short-lived precipitation increase are the principal effects of the A.D. 1300 event. Temperature fall stressed ecosystems, but its effects are difficult to separate from those of the others. Sea-level fall saw dramatic falls of nearshore coral-reef productivity and the formation of (habitable) reef islands (motu). Precipitation rise increased upland erosion and lowland sedimentation. The human outcomes of these environmental changes are organized in three groups: conflict, settlement-pattern changes, and the end of long-distance voyaging. Conflict increased during/after the A.D. 1300 event because of an abrupt fall in the food resource base. This also caused large coastal settlements on many islands to be abandoned in favor of caves and/or smaller fortified hilltop settlements. Successful long-distance voyages ceased during/after the A.D. 1300 event, as did interisland exchange within many archipelagoes. The regional (rather than local) extent of the A.D. 1300 event is demonstrated. Questions remain as to its synchronicity and duration.

Misperceptions of climate-change risk as barriers to climate-change adaptation: a case study from the Rewa Delta, Fiji

While increasing research is focusing on the effective adaptation to climate change in richer (developed) countries, comparatively little has focused specifically on this subject in poorer (developing) countries such as most in the Pacific Islands region. A significant barrier to the development of effective and sustainable adaptive strategies for climate change in such places is the gap between risk and perceived risk. This study looks at a vulnerable location in Fiji—the densely populated Rewa River Delta where environmental changes resulting from shoreline retreat and floods are expected to increase over the next few decades and entail profound societal disruption. The numbers of people living in the Rewa Delta who know of climate change and could correctly identify its contributory causes are few although many rank its current manifestations (floods, riverbank erosion, groundwater salinization) as among their most serious environmental challenges. While lack of awareness is a barrier to adaptation, there are also cultural impediments to this such as short-term planning perspectives, spiritual beliefs, traditional governance structures. One way forward is to empower community leaders in places like the Rewa Delta to make appropriate decisions and for regional governments to continue working together to find solutions that acknowledge the variation in sub-regional trans-national vulnerability to climate change.

Human-Environment Relationships in the Pacific Islands around A.D. 1300

This paper traces the history of human-environment interactions in the Pacific Islands during the last millennium, focusing on three main periods: the Little Climatic Optimum, the Little Ice Age, and, in greatest detail, the transition around A.D. 1300 between the two. The Little Climatic Optimum (approximately A.D. 750-1300) was marked by warm, rising temperatures, rising sea level and probably increasing aridity. The latter condition was linked to development of water-conservatory strategies (agricultural terracing being the most common) requiring cooperation between human groups which facilitated formation of large nucleated settlements and increased sociopolitical complexity. The transition period (approximately A.D. 1270-1475) involved rapid temperature and sea-level fall, perhaps a short-lived precipitation increase. Temperature fall stressed crops and reef organisms, sea-level fall lowered water tables and exposed reef surfaces reducing their potential as food resources for coastal dwellers. Increased precipitation washed away exposed infrastructure. Consequently food resource bases on many islands diminished abruptly across the transition. The Little Ice Age (approximately A.D. 1300-1800) was marked by cooler temperatures and lower sea levels. The lingering effects of the earlier transition largely determined human lifestyles during this period. Conflict resulted from resource depletion. Unprotected coastal settlements were abandoned in favour of fortified inland, often upland, settlements. Climate change is suggested to have been a important determinant of human cultural change during the last millennium in the Pacific Islands.

Sea-Level Rise by 2100

In his News and Analysis piece reporting on the newly released fifth assessment report (AR5) by Working Group I (WGI) of the Intergovernmental Panel on Climate Change (IPCC) (“A Stronger IPCC Report,” 4 October, p. [23][1]), R. A. Kerr highlights three fundamental conclusions about climate change that were assessed with equal or greater confidence than in previous IPCC reports. He also points to three “contentious points” on which he states that the AR5 “took a moderate line.” Kerr includes sea-level projections among these points, and reports “a rise of 40 to 60 centimeters by late in the century and a worst case of 1 meter by 2100, [which is] higher than in 2007 but far below the meter or two of sea-level rise that some expect.” As the authors of the IPCC WGI AR5 chapter on “Sea-Level Change,” we wish to clarify that for the highest emission scenario considered (RCP8.5), the AR5 reported a “likely” range of 0.45 to 0.82 m for sea-level projections for the late 21st century (average over 2081 to 2100) and of 0.52 to 0.98 m by 2100. The difference in sea level between these two periods is large because in 2081 to 2100, the “likely” rate of rise is 8 to 16 mm per year, which is up to about 10 times the average rate of rise during the 20th century. In the calibrated uncertainty language of the IPCC, this assessed likelihood means that there is roughly a one-third probability that sea-level rise by 2100 may lie outside the “likely” range. That is, the AR5 did not exclude the possibility of higher sea levels. However, we concluded that sea levels substantially higher than the “likely” range would only occur in the 21st century if the sections of the Antarctic ice sheet that have bases below sea level were to collapse. We determined with medium confidence that “this additional contribution would not exceed several 10ths of a meter of sea-level rise during the 21st century.” We could not define this possible contribution more precisely because “there is currently insufficient evidence to evaluate the probability of specific levels above the assessed ‘likely’ range.” The upper boundary of the AR5 “likely” range should not be misconstrued as a worst-case upper limit, as was done in Kerrs story as well as elsewhere in the media and blogosphere. For policy and planning purposes, it may be necessary to adopt particular numbers as an upper limit, but according to our assessment, the current state of scientific knowledge cannot give a precise guide. ![Figure][2] CREDIT: ANDREW MANDEMAKER/WIKIMEDIA COMMONS [1]: /lookup/doi/10.1126/science.342.6154.23-b [2]: pending:yes

Nature‐Society Interactions in the Pacific Islands

ABSTRACT This paper focuses on nature—society interactions in the Pacific Islands before European contact about 200 years ago. It argues that the character of early interactions was decided by both the nature of a particular island environment and the intentions of the human settlers. Throughout the pre‐European contact human history of the Pacific Islands, environmental changes of extraneous cause have been the main control of societal and cultural change. This environmental determinist view is defended using many examples. The contrary (and more popular) cultural determinist view of societal change in the Pacific Islands is shown to be based on largely spurious data and argument. A key example discussed is the ‘AD 1300 Event’, a time of rapid temperature and sea‐level fall which had severe, abrupt and enduring effects on Pacific Island societies. It is important to acknowledge the role of environmental change in cultural transformation in this region.

The Lapita Occupation at Naitabale, Moturiki Island, Central Fiji

In 2003 the authors discovered and excavated a Lapita site at Naitabale close to the southern end of Moturiki Island (central Fiji). Today the site is 350 m inland from the coast, but in Lapita times it was located behind the active beach ridge. A large collection of potsherds (including 92 dentate-stamped or incised Lapita sherds), shell, and animal bones was recovered, together with a human burial. Sherd decorations show affinities with the Western Lapita Province rather than the Eastern Lapita Province (which includes Fiji). Temper analyses of 45 Lapita sherds do not show any unmistakably exotic (to Fiji) pottery, but 29 percent are nonlocal to Moturiki and nearby islands. Fish bones are mostly from inshore species (dominated by Scaridae), while nonfish vertebrates are dominated by turtle and include dog and chicken. Shellfish remains are dominated by gastropods, mostly Strombus spp. (43 percent of gastropod MNI). The surf clam (Atactodea striata) accounts for 38 percent of bivalve MNI, with Anadara antiquata and Gafrarium pectinatum each representing 14 percent of the bivalve MNI. The skeleton is that of a woman (Mana) 161–164 cm tall who died at 40–60 years of age. Six radiocarbon dates from bones overlap 2740–2739 cal. years B.P. (790–789 B.C.). The mandible lacks antegonial notches but is not a proper rocker jaw. The cranium was better preserved than any Lapitaassociated skeleton hitherto described, which allowed the head to be reconstructed. Stable-isotope analyses show that her diet contained significant amounts of reef foods but was probably dominated by terrestrial plants. The Lapita occupation of Naitabale is likely to have begun by 2850 cal. years B.P. (900 B.C.). Radiocarbon dates and pottery decorative styles both suggest Naitabale was first occupied within the early part of the Lapita history of Fiji.

Integration of Indigenous Knowledge and Disaster Risk Reduction: A Case Study from Baie Martelli, Pentecost Island, Vanuatu

Despite reaching heights of >6 m and destroying a sizeable coastal settlement at the head of Baie Martelli (Pentecost Island, Vanuatu, South Pacific), the 26 November 1999 tsunamis caused only five fatalities from a threatened population of about 300 persons, most of whom fled inland and upslope before the waves struck. This remarkable survival rate is attributed to both indigenous knowledge, largely in the form of kastom knowledge, and information obtained from a video about tsunamis that was shown in the area three weeks earlier. Interviews with 55 persons who experienced this tsunami suggest that indigenous knowledge about tsunami risk and response in Baie Martelli was well known among key members of the community and was probably largely responsible for the appropriate response. Future strategies for disaster risk reduction should involve maintaining such indigenous knowledge in such communities and supplementing this where needed with scientific knowledge filtered through indigenous culture and language.

On the convergence of myth and reality: examples from the Pacific Islands

Various (groups of) myths from the Pacific Islands are discussed. Generic groups considered are diluvian myths, myths involving abrupt subsidence, abrupt uplift, and simultaneous abrupt subsidence and uplift. Specific myths, recently validated, illustrate the superiority of the mythic explanation for recent volcanism over available geological information, and the possibility of myth recalling a migration which took place nearly 3000 years ago. The implications of the correct interpretation of the geographical basis of myths for an understanding of environmental change in the Pacific are explored. Particularly in a region where written history is relatively recent, myths have the potential for extending available chronologies of particular phenomena and allow consideration of issues such as the role of infrequent catastrophic events in landscape evolution and the role of (rapid) environmental change in cultural transformation to be considered more fully.

Revising ideas about environmental determinism: human-environment relations in the Pacific Islands

Rapid cooling and sea–level fall around AD 1300, perhaps accompanied by increased storminess, had major impacts on Pacific Island environments including water–table fall, reef–surface death, increased lagoonal turbidity, and the conversion of seawater embayments to brackish–water wetlands. These environmental changes had severe and lasting impacts on Pacific Island societies, largely associated with a massive (perhaps 80 per cent) reduction in the food resource base on some islands. Conflict ensued, coastal villages were abandoned on high islands in favour of fortified inland sites, settlements on large atoll islands were dispersed. It is clear that environmental change a the major cause of last–millennium cultural transformation in the Pacific Islands, a conclusion which is likely to apply elsewhere.

THE A.D. 1300 EVENT IN THE PACIFIC BASIN

Around a.d. 1300 the entire Pacific Basin (continental Pacific Rim and oceanic Pacific Islands) was affected by comparatively rapid cooling and sea‐level fall, and possibly increased storminess, that caused massive and enduring changes to Pacific environments and societies. For most Pacific societies, adapted to the warmer, drier, and more stable climates of the preceding Medieval Climate Anomaly (a.d. 750–1250), the effects of this A.D. 1300 Event were profoundly disruptive, largely because of the reduction in food resources available in coastal zones attributable to the 70–80‐centimeter sea‐level fall. This disruption was manifested by the outbreak of persistent conflict, shifts in settlements from coasts to refugia inland or on unoccupied offshore islands, changes in subsistence strategies, and an abrupt end to long‐distance cross‐ocean interaction during the ensuing Little Ice Age (a.d. 1350–1800). The A.D. 1300 Event provides a good example of the disruptive potential for human societies of abrupt, short‐lived climate changes.