Search

Sea level rise (SLR) is a long-lasting consequence of climate change because global anthropogenic warming takes centuries to millennia to equilibrate for the deep ocean and ice sheets. SLR projections based on climate models support policy analysis, risk assessment and adaptation planning today, despite their large uncertainties. The central range of the SLR distribution is estimated by process-based models. However, risk-averse practitioners often require information about plausible future conditions that lie in the tails of the SLR distribution, which are poorly defined by existing models. Here, a community effort combining scientists and practitioners builds on a framework of discussing physical evidence to quantify high-end global SLR for practitioners. The approach is complementary to the IPCC AR6 report and provides further physically plausible high-end scenarios. High-end estimates for the different SLR components are developed for two climate scenarios at two timescales. For global warming of +2°C in 2100 (RCP2.6/SSP1-2.6) relative to pre-industrial values our high-end global SLR estimates are up to 0.9 m in 2100 and 2.5 m in 2300. Similarly, for a (RCP8.5/SSP5-8.5), we estimate up to 1.6 m in 2100 and up to 10.4 m in 2300. The large and growing differences between the scenarios beyond 2100 emphasize the long-term benefits of mitigation. However, even a modest 2°C warming may cause multi-meter SLR on centennial time scales with profound consequences for coastal areas. Earlier high-end assessments focused on instability mechanisms in Antarctica, while here we emphasize the importance of the timing of ice shelf collapse around Antarctica. This is highly uncertain due to low understanding of the driving processes. Hence both process understanding and emission scenario control high-end SLR. publishedVersion

This chapter assesses extremes and abrupt or irreversible changes in the ocean and cryosphere in a changing climate, to identify regional hot spots, cascading effects, their impacts on human and natural systems, and sustainable and resilient risk management strategies. It is not comprehensive in terms of the systems assessed and some information on extremes, abrupt and irreversible changes, in particular for the cryosphere, may be found in other chapters.

Successful mammalian pregnancies are a result of complex physiological, endocrinological, and immunological processes that combine to create an environment where the mother is tolerant to the semi-allogeneic fetus. Our knowledge of the mechanisms that contribute to maternal tolerance is derived mainly from human and murine studies of haemochorial placentation. However, as this is the most invasive type of placentation it cannot be assumed that identical mechanisms apply to the less invasive epitheliochorial placentation found in other species such as ruminants. Here, we examine three features associated with reproductive immune regulation in a transformed ovine trophoblast cell line andex-vivoovine reproductive tissues collected at term, namely: major histocompatibility complex (MHC) expression, Indoleamine 2,3 dioxygenase-1 (IDO-1) expression, and Natural Killer (NK) cell infiltration. High levels of MHC class I protein expression were detected at the surface of the trophoblast cell line using a pan-MHC class I specific monoclonal antibody. The majority of MHC class I transcripts isolated from the cell line clustered with classical MHC alleles. Transcriptional analysis of placental tissues identified only classical MHC class I transcripts. We found no evidence of constitutive transcription of IDO-1 in either the trophoblast cell line or placental tissues.Ex-vivotissues collected from the materno-fetal interface were negative for cells expressing NKp46/NCR1. Collectively, these observations suggest that the relatively non-invasive synepitheliochorial placentation found in sheep has a more limited requirement for local immunoregulation compared to the more invasive haemochorial placentation of primates and rodents.

Population growth in towns and cities requires new construction of homes and conversion of native land use to urban and suburban landscapes. Municipal tap water is generally used for irrigating these urban and suburban landscapes and its water quality can differ globally dependent on whether it is sourced from ground or surface waters. We examined runoff dissolved organic carbon (DOC) and organic nitrogen (DON) concentrations, fluxes and exports from newly installed, fertilized and unfertilized St. Augustine (Stenotaphrum secundatum (Walt.) Kuntze ‘Raleigh’) sod irrigated with a sodic municipal tap water during two 5-week establishment periods (August and September). In unfertilized plots, concentrations of DOC in runoff significantly increased from 20.5 to 73.7 mg L-1 and from 29.6 to 113.3 mg L-1 Runoff concentrations of DOC in fertilized plots significantly increased from 27.3 to 72.0 mg L-1 and from 30.0 to 120.3 mg L-1. Concentrations of DON in runoff did not increase in either unfertilized or fertilized plots. Total DOC exports were 2036 ± 803 kg km-2 and 3341 ± 227 kg km-2 and DON exports were 99 ± 43 kg km-2 and 134 ± 15 kg km-2 respectively for the two turfgrass installation dates for the unfertilized plots. Fertilization had no significant effect on DOC and DON exports (p = 0.29 and 0.18). Na+, K+, Mg2+ and Ca2+ were implicated in both DOC and DON fluxes suggesting that as resources for irrigation water for urban landscapes decline and alternative irrigation water supplies such as grey and black water are utilized we would expect, due to their higher Na+ content that DOC and DON fluxes to urban watersheds will increase.

The spatial variability of preferential pathways for water and chemical transport in a field soil, as visualized through dye infiltration experiments, was studied by applying multifractal and wavelet transform analysis (WTA). After dye infiltration into a 4 m² plot located on a Vertisol soil near College Station, Texas, horizontal planes in the subsoil were exposed at 5 cm intervals, and dye stain patterns were photographed. Box-counting methods and WTA were applied to all of the 16 digitalized high-resolution dye images and to the dye-mass image obtained merging all sections. The well-known Devil's staircase multifractal was also used to illustrate wavelet-based analysis. Our results suggest that wavelet methods can complement box-counting analysis in the context of multiscaling structure analysis.

This study presents an analysis of the wind‐wave climate on the south‐east Australian continental margin and its potential changes under the effects of projected climate change. The wind‐wave climate is modelled for three 20 year time‐slices (1981–2000, 2031–2051, and 2081–2100) using a dynamical wave modelling approach in which the WaveWatch III spectral wave model, with a nested domain SWAN model, is the region of interest. Surface wind forcing is obtained from an ensemble of three global climate model runs (CSIRO Mk3.5, GFDLcm2.0, and GFDLcm2.1) dynamically downscaled using CSIRO's Cubic conformal atmospheric model (CCAM), under two greenhouse gas emission scenarios (a high emission SRES A2 and low emission SRES B1 scenario). A third level of uncertainty associated with adjusting climate model derived winds for climate and variability bias is found to be the largest source of uncertainty among the limited range of sources considered in the twenty‐eight 20 year wave model simulations undertaken herein. The ensemble of wave model runs for the 2081–2100 time‐slice project a robust decrease in mean significant wave height along the south‐east Australian coast relative to present (1981–2000) conditions. The magnitude of projected change in mean annual significant wave height is less than 0.2 m, with larger values in the north of the region of interest, and is associated with a projected decrease in storm wave energy in the region. An anticlockwise rotation in mean wave direction of approximately 5° is also projected over the same period.

Psittacine beak and feather disease (PBFD) is a viral disease distributed worldwide with a potentially critical impact on many rare parrots. While efforts have been made to determine its prevalence in wild and captive psittacines, only limited work has been done to document complete genomes of its causative agent, beak and feather disease virus (BFDV). Here, we describe five full genomes of BFDV isolated from wild specimens of an endemic New Zealand parrot, the red-fronted parakeet (Cyanoramphus novaezelandiae). The isolates share [99% nucleotide similarity amongst themselves and *91–92% similarity to BFDV isolates from southern Africa, Europe and Australia. A maximum-likelihood (ML) phylogenetic tree including 42 other full-genome sequences indicated that the five isolates from red-fronted parakeets represent an undescribed genotype of BFDV. These isolates are evolutionarily most closely related to the Cacatuini isolates from Thailand and the Lorinae isolates from Australia in the rep gene ML tree; however, in the cp ML tree, the evolutionary relationship is closer to viruses found in the Psittacini.