Climate Change and Sea Level Rise

The colonization of interior North America during the late Pleistocene, ca. 20k-10k cal yr BP, would have been profoundly shaped by physiographic features early explorers and settlers encountered, such as the location of major river valleys, mountain ranges, deserts, pluvial and periglacial lakes, and ice-sheet margins, and in coastal areas by the dramatic changes in sea level that were occurring. An examination of the relationship between changes in sea level and the extent of the Gulf and Atlantic Coastal Plains in the vicinity of the southeastern United States indicates that, because of the uneven topography of the now submerged continental shelf, sea-level rise or fall does not closely correspond to the area lost or gained. During some periods, notably MWP-1A (Meltwater Pulse 1A), only small areas of the Coastal Plain were lost, while in others, such as during the Younger Dryas and MWP-1B, much larger areas were affected. The widespread appearance of Clovis in the interior of the Southeast, and the apparent reduction or reorganization of immediate post-Clovis settlement in the Coastal Plain, and an increase in population-or at least no evidence for reduction-farther into the interior of the region may be related to these changes in sea level. Evaluating these ideas will require much new fieldwork and the collection, compilation, and public dissemination of primary archaeological data among the professional community.

The colonization of interior North America during the late Pleistocene, ca. 20k-10k cal yr BP, would have been profoundly shaped by physiographic features early explorers and settlers encountered, such as the location of major river valleys, mountain ranges, deserts, pluvial and periglacial lakes, and ice-sheet margins, and in coastal areas by the dramatic changes in sea level that were occurring. An examination of the relationship between changes in sea level and the extent of the Gulf and Atlantic Coastal Plains in the vicinity of the southeastern United States indicates that, because of the uneven topography of the now submerged continental shelf, sea-level rise or fall does not closely correspond to the area lost or gained. During some periods, notably MWP-1A (Meltwater Pulse 1A), only small areas of the Coastal Plain were lost, while in others, such as during the Younger Dryas and MWP-1B, much larger areas were affected. The widespread appearance of Clovis in the interior of the Southeast, and the apparent reduction or reorganization of immediate post-Clovis settlement in the Coastal Plain, and an increase in population-or at least no evidence for reduction-farther into the interior of the region may be related to these changes in sea level. Evaluating these ideas will require much new fieldwork and the collection, compilation, and public dissemination of primary archaeological data among the professional community.

Sea Research Society's poster "Looking At The Forward Running Clocks' - Carbon Cycles and Time From Pleistocene to Present" was presented at a major international conference organised by Royal Anthropological Institute (RAI): "Anthropology, Weather and Climate Change". This international conference took place at the British Museum from 27th to 29th May 2016. RAI organised it in conjunction with the British Museum's Department for Africa, Oceania and the Americas. Sea Research Society was asked during the conference to re-formulate this poster to an article for a peer-reviewed science periodical, the online science publication "Arcadia - Explorations in Environmental History", published by Environment and Society Organisation, by its editor Katrin Kleemann. We are working to issue this poster in a periodical format in a due course.  The key points and observations of the RAI 2016 conference poster and the forthcoming paper are:

The natural carbon and methane cycles are hugely disrupted by today’s human activities. The Palaeolithic meat-hunting evolved first to a very small-scale Neolithic cattle-rearing, then to today’s mega-scale industrial farms that increase methane in the atmosphere. Meat consumption, what initially started as a globally harmless hunter-gatherer activity has evolved into today's massive, environmentally highly stressful activity as world population has grown together with the land scarcity. Thus meat consumption has today emerged as one of the most important drivers of the anthropogenic climate change due to its addition of methane to the atmosphere.

The poster presents a hypothesis where the end of Palaeolithic (Pleistocene) thawing permafrost soils and sea beds (as well as the changes in the sea bed pressurization), destabilised methane clathrates and became important and major contributor to the carbon cycle at times of lowering sea levels.  Meanwhile, the Pleistocene era's cold oceans captured carbon from the atmosphere more effectively than during the warmer Holocene. Thus it is postulated that the destabilised methane clathrates (both from on-shore and off-shore permafrost) replenished the atmospheric carbon stocks by carbon-12 and carbon-13 rich 'old' carbon isotopes (due to above sea bed depressurisation and melting-derived permafrost soil outgassing). The permafrost-released 'old carbon' thus skews the Pleistocene to Holocene Thermal Maximum eras' carbon isotope portfolio in biological samples which results in a lowered carbon-14 content within biological samples (as the plants do not differentiate between the three carbon isotopes).

The presence of permafrost-released old carbon can be detected by plant metabolistic research of the period's samples from which it could be concluded that short-term carbon-12/13 permafrost release intake (hourly and daily isotope variation in carbon synthesis [changes in temperature and prevailing wind direction]), seasonal carbon isotope variation (spring-autumn in carbon synthesis [spring-time carbon capture from the atmosphere versus later releases of old permafrost carbon once permafrost melts towards the autumn]) and multi-year carbon isotope trend (the long-term build-up of old carbon in the air mass) analyses can be carried out. These result in radiocarbon outliers, or radiocarbon-dilution, in biological and archaeological materials retrieved from Pleistocene to Holocene Thermal Maximum period.

The poster (paper) also discusses the reasons for the absence of elevated carbon dioxide and methane levels in the era's ice cores and correlates this anomaly with the present-day rapid deposition of carbon, especially methane (that has increased 4.4-times faster at 74 mb level in the atmosphere 2013-2017 that it does at ground level). This is due to cessation of the filtering effect of hydroxyl that tends to oxidise methane relatively rapidly into carbon dioxide. This filtration mechanism appears to have faltered since 2013 allowing the lighter-than-air methane to rise and accumulate in the upper troposphere and stratosphere where there is very little hydroxyl to oxidise it. When this is taken into account, a new image of 3-tier greenhouse effect emerges in the Arctic region, where methane traps Outgoing Longwave Radiation (OLR) extremely efficiently at high altitudes, carbon dioxide traps it at lower altitudes and melted snow and ice cover forces ground to absorb more sunlight at surface level. As methane appears to be accumulating in the current Arctic warming well above all glaciers, this must also have happened invisibly throughout the Pleistocene glaciations and contributed to the period's highly volatile climatic rollercoaster movements.

The poster (paper) then discusses methods and presents examples of some well-known mega radiocarbon-outliers as potential artefacts of the above proposed radiocarbon-dilution effect (which did not leave any signs of its existence in the ice cores of the past eras as methane's primary build up - in the absence of oxidising hydroxyl - occurs well above the glaciers at the very high altitudes of the upper troposphere and stratosphere). Moreover, this implies now that the Arctic might very soon and unexpectedly enter into a runaway warming state from the above-said high altitude methane accumulation which originates from melted and perforated soils and sea beds - and equally importantly from the positive feedback of the lower troposphere's hydroxyl filter failure since 2013 (as illustrated in the bar chart). The paper's major concern is less on the carbon dating effects, but rather on the possible global warming risk of a very large increase in atmosphere's carbon-12 and carbon-13 stock from methane. This release of carbon occurs initially as high-altitude methane and only later as closer-to-surface level carbon dioxide (which leaves its signal behind in the ice cores; see the temperature curve diagram of the warming occurring prior to carbon dioxide build-up in the ice cores (the red arrows) which warming trend is, thereafter often arrested and punctuated suddenly by the rapid collapses of major ice shelves and ice sheets or glacial melt water reservoir discharges, i.e. producing the cold 'Dryases' (the blue arrows). These releases will obviously skew future carbon-14 readings even further and possibly even more than our anthropogenic fossil carbon build up from the present-day use of fossil fuels.

More examples of radiocarbon-dilution effect (radiocarbon mega-outliers) will be given in the forthcoming paper. The poster invitation was presented at the conference prospectus: "RAI/BM16 - Royal Anthropological Institute, British Museum Department of Africa, Oceania and the Americas: 'Anthropology, Weather and Climate Change - British Museum, Clore Centre, 27-29 May 2016'. Conference programme and book of abstracts", published by the conference organisers Royal Anthropological Institute (RAI), The British Museum (BM) and the Wenner-Gren Foundation (WG), on a page 148.

Στην παρούσα σύντομη παρουσίαση συνοψίζονται αποτελέσματα διερευνήσεων με υπολογιστικές προσομοιώσεις αναφορικά με την επίδραση της Κλιματικής Αλλαγής στην εξέλιξη της θαλάσσιας στάθμης λόγω των μετεωρολογικών παλιρροιών και επομένως και των δυνητικών παράκτιων πλημμυρών, στη Μεσόγειο και πιο ειδικά στο Αιγαίο και το Ιόνιο Πέλαγος και την ευρύτερη ελληνική παράκτια ζώνη.

This paper focuses on possible scenarios of land use and land tenure in the event of a permanent sea level rise on Wallis Island, part of the French Overseas Territory Wallis and Futuna in the South Pacific. This island holds a unique place in the French system, having its own king and a traditional power structure relying on Polynesian traditions. Land issues are managed through customary law, and this system offers flexible opportunities that can respond to contextual need. Land tenure is based on lines of descent; those who are ‘part of’ a certain land parcel are identified through his or her ancestry. This traditional system needs to be analysed as regards its effectiveness and its ability to respond to new environmental and political challenges. Local resource use, and shifting residency and agriculture patterns challenge land tenure. With the majority of the population inhabiting the coastline, potential migration opportunities to the higher interior of the island within the residents’ own properties in the event of sea level rise need to be explored. Every Wallisian has access to several land parcels, which are distributed across the island.