This report assesses options for developing an integrated nature and climate strategy in Oxfordshire, based on Oxfordshire’s Local Nature Recovery Strategy (LNRS). By combining the LNRS map with the high-resolution Agile Opportunity Map of Oxfordshire developed by the University of Oxford, we developed a detailed spatial scenario for habitat restoration within the LNRS network, removing constraints such as buildings, roads, water, existing woodland and other priority habitats. We prioritised potential measures to maximise carbon sequestration while still creating a balanced mix of habitats in line with the LNRS priorities. The scenario included restoration of woodland, grassland, wetlands, heathland and tree-grass-scrub mosaics, as well as an increase of 40% in hedgerow length, widespread adoption of silvopasture and silvoarable agroforestry on farmland, and measures to improve soil health and enhance soil carbon on arable land. Urban habitats and ponds were out of scope for this study, and peatland was not considered as there is only 17 hectares in Oxfordshire. We show that a high-integrity nature-based carbon strategy could increase carbon storage in Oxfordshire by up to 28% (6 million tonnes of carbon) once habitats are mature (e.g. 100 years for woodlands). Over the next 30 years, this strategy could sequester over 180,000 tonnes of carbon annually, offsetting 18% of Oxfordshire’s 2023 emissions. However, only 38,000 tonnes of this total estimated sequestration is covered by existing or emerging market mechanisms (Wilder Carbon, the Woodland Carbon Code, and estimated units under future Soil, Agroforestry and Hedgerow carbon codes), offsetting 4% of emissions. This is because these market schemes set aside risk buffers of up to 40% of the estimated carbon savings, and do not issue carbon units in advance for all habitat transitions. The most notable missing marketable transition is restoration of intensively cultivated grassland to semi-natural grassland, as well as restoration of wetland and heathland on mineral soils. However, these can be claimed in retrospect under the Wilder Carbon scheme, following implementation and verification of the actual carbon gain, provided good baseline measurements have been taken. Extending hedgerow and soil carbon restoration to the whole county rather than just within the LNRS network could increase sequestration to offset 20% of emissions, of which 7% are currently marketable. These broad estimates are subject to high levels of uncertainty and represent upper limits, as they assume almost complete conversion or enhancement of low-grade farmland within the LNRS network over the next few decades, which is unlikely to occur in practice. If emissions continue to decline as planned, the share of residual emissions that could be offset through nature-based solutions could increase significantly, although the sequestration rate will decline as restored habitats mature. Sequestration from nature-based solutions can therefore play an important role, especially in the next 100 years, but this must be accompanied by continued strong measures to reduce emissions from fossil fuels and land-use. As well as playing a key role in delivering both nature recovery and net zero objectives, this strategy would also deliver multiple benefits for climate change adaptation, helping to reduce the impacts of floods, droughts and heatwaves, and would help to support human health and well-being through improving air quality and providing nature-rich green spaces for recreation and relaxation. It can help to support more resilient food production, by boosting populations of pollinators and pest predators, and protecting from soil erosion. In contrast, other carbon sequestration options such as fast-growing non-native plantations generally deliver little or no benefit for biodiversity, while the impacts of biochar are highly dependent on the biomass source. However, this strategy would have trade-offs for food production, as farmland is converted to woodland or less productive grassland options. This is minimised through avoiding conversion of Grade 1 and 2 land to non-agricultural use, but it would still lead to leakage of emissions due to food production in other areas, unless policies also encourage a shift to more plant-rich diets that require less land area. Delivery of this strategy depends on strong national and local support mechanisms, including adequate carbon prices and payments or incentives for wider benefits, such as through agri-environment schemes. Restored habitats must be protected from development and other threats, and managed sensitively to deliver long-term benefits for carbon, nature and people. Alongside restoring habitats, it is also vital to protect existing habitats for their stored carbon as well as biodiversity and ecosystem services. With good support from both national and local policy mechanisms, this high-integrity policy can play a key role in delivering multiple benefits for carbon, nature and people in Oxfordshire.
A. J. Smith (Thu,) studied this question.