Climate change is affecting archaeological sites and landscapes around the world. Increased rainfall, more frequent extreme weather events, higher temperatures and rising seas not only create new risks but also exacerbate existing vulnerabilities and threats. Building on an earlier Antiquity article that explored climate change and arctic archaeology (Hollesen et al. 2018), this special section provides a global perspective on the impact of climate change on archaeological sites and landscapes and how archaeologists and cultural heritage managers are responding. This article introduces the following three contributions, outlining their main findings to provide an overview of the various challenges around the world, and highlighting current gaps in knowledge and future research opportunities.

The Intergovernmental Panel on Climate Change has documented wide-ranging changes to the world's coasts and oceans, with significant further change predicted. Impacts on coastal and underwater heritage sites, however, remain relatively poorly understood. The authors draw on 30 years of research into coastal and underwater archaeological sites to highlight some of the interrelated processes of deterioration and damage. Emphasising the need for closer collaboration between, on one hand, archaeologists and cultural resource managers and, on the other, climate and marine scientists, this article also discusses research from other disciplines that informs understanding of the complexity of the interaction of natural and anthropogenic processes and their impacts on cultural heritage.

Wetland archaeological sites offer excellent but vulnerable preservation conditions. This article presents examples of threats to such sites that may be enhanced, or diminished, by climate change, discusses methods for predicting and quantifying impacts, and examines what heritage managers can do to mitigate their effects. The consequences of climate change for wetland archaeological sites are likely to be severe and widespread but hard to predict and with significant local variation. At the same time, wetlands are increasingly acknowledged for their ability to sequester carbon and to mitigate climate change, prompting an increased focus on their protection that may also benefit wetland archaeology.

Climate change threatens archaeological sites and cultural landscapes globally. While to date, awareness and action around cultural heritage and climate change adaptation planning has focused on Europe and North America, in this article, the authors address adaptation policy and measures for heritage sites in low- and middle-income countries. Using a review of national adaptation plans, expert survey and five case studies, results show the varied climate change adaptation responses across four continents, their strengths and weaknesses, and the barriers to be addressed to ensure better integration of cultural heritage in climate change adaptation planning.

Archaeological nomenclature influences the classification of cultural phases, objects and related behavioural interpretations. The term ‘Madrasien’, synonymous with the Acheulian, was a key concept in early studies of Indian prehistory, encompassing notions of geographical/administrative boundaries, tool types, cultural identities and migrations. Madrasien was coined in 1931 by the Austrian prehistorian Oswald Menghin and established in South Asian prehistory by V.D. Krishnaswami. Here, the authors trace the evolution of the term, situating it within the wider discourses in Indian prehistory and examining its role in shaping ideas on South Asian Palaeolithic nomenclatures. The Madrasien was gradually replaced by the current medley of African, European and Southeast Asian terminologies.

The megalithic pillar sites found around Lake Turkana, Kenya, are monumental cemeteries built approximately 5000 years ago. Their construction coincides with the spread of pastoralism into the region during a period of profound climate change. Early work at the Jarigole pillar site suggested that these places were secondary burial grounds. Subsequent excavations at other pillar sites, however, have revealed planned mortuary cavities for predominantly primary burials, challenging the idea that all pillar sites belonged to a single ‘Jarigole mortuary tradition’. Here, the authors report new findings from the Jarigole site that resolve long-standing questions about eastern Africa's earliest monuments and provide insight into the social lives, and deaths, of the region's first pastoralists.

Studies of ‘food globalisation’ have traced the dispersal of cereals across prehistoric Eurasia. The degree to which these crops were accompanied by knowledge of soil and water preparation is less well known, however. The authors use stable isotope and archaeobotanical analyses to trace long-term trends in cultivation practices on the Loess Plateau (6000 BC–AD 1900). The results indicate that ancient farmers cultivated grains originating in South-west Asia and used distinct strategies for different species. Barley was integrated into pre-existing practices, while wheat was grown using novel soil and water management strategies. These distinct approaches suggest that the spread of prehistoric crops and knowledge about them varied by local context.

Oracle bone inscriptions of the late Shang Dynasty (1250–1046 BC) record the burning of jade as a ceremonial sacrifice, a practice now corroborated archaeologically. The origins of ceremonial jade burning, however, are unclear. Using archaeometric methods and experimental archaeology, the authors examine an assemblage of jade objects from the late Liangzhu-period (2600–2300 BC) cemetery of Sidun. The cause of the jades’ variable surface colours has been long debated. The results presented here demonstrate that the colour changes relate to alterations in chemical composition due to exposure to fire. The evidence from Sidun confirms that the burning of jade in China commenced more than a millennium earlier than previously documented.

In a recent Antiquity article, Parker Pearson and colleagues (2021) presented results from excavations at Waun Mawn in south-west Wales, interpreting the site as a dismantled stone circle and source for some of the Bluestone pillars used in the Aubrey Holes at Stonehenge. Here, the author examines the evidence, showing that alternative interpretations are possible. Waun Mawn is argued to represent a series of smaller stone settings, typical of ceremonial sites in south-west Wales. Meanwhile the Aubrey Holes are shown to reflect a well-established regional sequence in which post circles are followed by pit circles. A Welsh ‘source-circle’ for Stonehenge cannot be excluded but, the author argues, the claim is unsupported by the current evidence.

Research on prehistoric mainland Southeast Asia is dominated by mortuary contexts, leaving processes such as the transition to sedentism relatively understudied. Recent excavations in southern Vietnam, however, have recovered new evidence for settlement. The authors report on investigations at the neolithic site of Loc Giang (3980–3270 cal BP) in southern Vietnam, where excavation revealed a vertical sequence of more than 30 surfaces. Microarchaeological analyses indicate that these features are carefully prepared lime mortar floors; the lime was probably produced from burnt shell. The floors date to between 3510 and 3150 cal BP, providing the earliest-known evidence for the use of lime mortar, and for durable settlement construction, in this region.

The port-city of Adulis in modern Eritrea was a key node on the Red Sea linking the Kingdom of Aksum to the Mediterranean, the Middle East and the Indian Ocean. Recent excavations at Adulis have reinvestigated two early Christian churches. New radiocarbon analysis dates both structures to the sixth and early seventh centuries AD, with multiple phases of architectural development reflecting changing use and liturgy. The author uses evidence for both continuity and change in architectural materials, construction styles and sacred practices to assess religious transition at Adulis, and across the Aksumite Kingdom more broadly. Moving beyond an archaeology of conversion, the article reinforces recent work on cosmopolitanism in the Horn of Africa.

Found only in a restricted area of north-west Australia, the Australian boab (Adansonia gregorii) is recognisable by its massive, bottle-shaped trunk, and is an economically important species for Indigenous Australians, with the pith, seeds and young roots all eaten. Many of these trees are also culturally significant and are sometimes carved with images and symbols. The authors discuss the history of research into carved boabs in Australia, and present a recent survey to locate and record these trees in the remote Tanami Desert. Their results provide insight into the archaeological and anthropological significance of dendroglyphs in this region and add to a growing corpus of information on culturally modified trees globally.

In response to Timothy Darvill's article, ‘Mythical rings?’ (this issue), which argues for an alternative interpretation of Waun Mawn circle and its relationship with Stonehenge, Parker Pearson and colleagues report new evidence from the Welsh site and elaborate on aspects of their original argument. The discovery of a hearth at the centre of the circle, as well as further features around its circumference, reinforces the authors’ original interpretation. The authors explore the evidence for the construction sequence, which was abandoned before the completion of the monument. Contesting Darvill's argument that the Aubrey Holes at Stonehenge originally held posts, the authors reassert their interpretation of this circle of cut features as Bluestone settings.