Proceedings of the Third Caldwell Conference, St. Catherines Island, Georgia, May 9-11, 2008

341 p. : ill. (some col.), maps (some col.) ; 26 cm. "Issued June 23, 2010." Includes bibliographical references (p. 303-341).The late Archaic of the American Southeast is typically described as a time of population growth, innovative developments in subsistence strategies, and increased social complexity. Although it is difficult to generalize, many early Woodland communities are characterized as relatively small scale, fairly mobile foragers organized into unranked or minimally ranked lineages and clans. Early Woodland groups also seem to be more socially isolated than their late Archaic predecessors, with a decline in regional exchange networks. The papers in this volume were presented at a conference entitled "What Happened in the Late Archaic?" which was co-sponsored by the American Museum of Natural History and the St. Catherines Island Foundation and held on St. Catherines Island (Georgia), May 9-11, 2008. The Third Caldwell Conference invited the participants to engage the appropriate archaeological data from the American Southeast, specifically addressing the nature of change during the late Archaic-early Woodland transition. This volume consists of a dozen substantive papers, followed by three discussant contributions. TABLE OF CONTENTS: Trend, tradition, and transition at the end of the Archaic / Tristram R. Kidder -- "Nothing but the river's flood" : late Archaic diaspora or disengagement in the lower Mississippi Valley and southeastern North America / Jon L. Gibson -- The two rings of St. Catherines Island : some preliminary results from the St. Catherines and McQueen shell rings / Matthew C. Sanger and David Hurst Thomas -- Two late Archaic period shell rings, St. Simon's Island, Georgia / Rochelle A. Marrinan -- The Archaic above Choctawhatchee Bay : hydrodynamics, adaptation, and abandonment / Rebecca Saunders -- Prehistoric landscapes of complexity : Archaic and Woodland period shell works, shell rings, and tree islands of the Everglades, South Florida / Margo Schwadron -- Shell rings and other settlement features as indicators of cultural continuity between the late Archaic and Woodland periods of coastal Florida / Michael Russo -- "What happened to the southeastern Archaic?" : a perspective from St. Catherines Island / David Hurst Thomas -- Leaving the rings : shell ring abandonment and the end of the late Archaic / Matthew C. Sanger -- The rhythms of space-time and the making of monuments and places during the Archaic / Victor D. Thompson -- Getting from the late Archaic to early Woodland in three middle valleys (those being the Savannah, St. Johns, and Tennessee) / Kenneth E. Sassaman -- Late Archaic? : what the hell happened to the middle Archaic? / Joe Saunders -- Thoughts on the late Archaic-early Woodland transition on the Georgia and South Carolina coasts / Chester B. DePratter -- Mounds, middens, and rapid climate change during the Archaic-Woodland transition in the southeastern United States / William H. Marquardt -- The end of the southeastern Archaic : regional interaction and archaeological interpretation / David G. Anderson

State of the climate in 2018

In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and$6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)