Restoration of coastal wetlands has the potential to deliver both climate change mitigation, called blue carbon, and adaptation benefits to coastal communities, as well as supporting biodiversity and providing additional ecosystem services. Valuing carbon sequestration may incentivize restoration projects; however, it requires development of rigorous methods for quantifying blue carbon sequestered during coastal wetland restoration. We describe the development of a blue carbon accounting model (BlueCAM) used within the Tidal Restoration of Blue Carbon Ecosystems Methodology Determination 2022 of the Emissions Reduction Fund (ERF), which is Australia's voluntary carbon market scheme. The new BlueCAM uses Australian data to estimate abatement from carbon and greenhouse gas sources and sinks arising from coastal wetland restoration (via tidal restoration) and aligns with the Intergovernmental Panel for Climate Change guidelines for national greenhouse gas inventories. BlueCAM includes carbon sequestered in soils and biomass and avoided emissions from alternative land uses. A conservative modeled approach was used to provide estimates of abatement (as opposed to on‐ground measurements); and in doing so, this will reduce the costs associated with monitoring and verification for ERF projects and may increase participation in blue carbon projects by Australian landholders. BlueCAM encompasses multiple climate regions and plant communities and therefore may be useful to others outside Australia seeking to value blue carbon benefits from coastal wetland restoration.

Soil pH is a critical parameter influencing numerous soil properties including nutrient cycling, microbial activity, inorganic carbon and metal speciation and criteria for classifying acid sulfate soils and soils with reactive aluminium (Podzols and Andosols). Accurate measurement of soil pH is essential for effective soil assessment, management and crop production. This review of soil pH focuses on techniques and challenges for measurement and utilises insights from a comprehensive global soil dataset ( n = 655,336). Soil pH has a global average of 6.36 with considerable regional variability. A Random Forest model of the global dataset identified total carbonate content, rainfall, evaporation, clay and organic carbon content as key drivers of soil pH ( R ² = 0.77, mean absolute error = 0.46 pH units). The advantages and limitations of various soil pH measurement methods (e.g., glass and solid‐state electrodes, colorimetric and spectrophotometric methods, infrared spectroscopy, remote sensing and specialised field assessment methods) are discussed. Care should be taken in choosing appropriate pH measurement techniques depending on the purpose of the measurement and nature of the soils. The use of electrolytes (e.g., CaCl ₂ and KCl) introduces variable changes in measured pH and, on average globally, pH measured in a 1:5 soil:0.01 M CaCl ₂ extract is ~0.7 pH units lower than that measured in a 1:5 soil suspension. Although the use of electrolytes can help stabilise pH measurements in low ionic strength soils, their use requires careful consideration, as they do not eliminate all seasonal variability (which may also be important to assess) and they can introduce large pH perturbations in sodic‐alkaline and acid sulfate soils. Varying soil‐to‐solution ratios have less influence on resultant pH values than electrolytes however the measurements at low soil‐to‐solution ratios (e.g., 1:1 soil:water) are preferable for accuracy. Perturbations from field pH conditions due to CO ₂ outgassing and oxidation are likely when wet soils, acid sulfate soils and/or sub‐soils are measured in the laboratory. These findings underscore the need for improved field measurement technology and further research on the measurement protocols to ensure accurate and reliable soil pH data, which are crucial for optimising agricultural practices and environmental management.