Publications

Abstract Ecosystems provide a range of goods and services that contribute toward human well-being. It is increasingly recognized that factors such as a growing and increasingly affluent world population, coupled with increased globalization of trade, are significantly influencing the delivery of ecosystem goods and services. This chapter argues that future energy policy must be designed based on a broad set of environmental and social considerations that examine the national and international implications of each energy technology. This approach ensures a more holistic overview of the costs and benefits associated with energy production, allowing society to make more informed choices about their futures, including how their energy is sourced, generated, and delivered.

Livestock grazing intensity (GI) is thought to have a major impact on soil organic carbon (SOC) storage and soil quality indicators in grassland agroecosystems. To critically investigate this, we conducted a global review and meta-analysis of 83 studies of extensive grazing, covering 164 sites across different countries and climatic zones. Unlike previous published reviews we normalized the SOC and total nitrogen (TN) data to a 30 cm depth to be compatible with IPCC guidelines. We also calculated a normalized GI and divided the data into four main groups depending on the regional climate (dry warm, DW; dry cool, DC; moist warm, MW; moist cool, MC). Our results show that taken across all climatic zones and GIs, grazing (below the carrying capacity of the systems) results in a decrease in SOC storage, although its impact on SOC is climate-dependent. When assessed for different regional climates, all GI levels increased SOC stocks under the MW climate (+7.6%) whilst there were reductions under the MC climate (−19%). Under the DW and DC climates, only the low (+5.8%) and low to medium (+16.1%) grazing intensities, respectively, were associated with increased SOC stocks. High GI significantly increased SOC for C4-dominated grassland compared to C3-dominated grassland and C3-C4 mixed grasslands. It was also associated with significant increases in TN and bulk density but had no effect on soil pH. To protect grassland soils from degradation, we recommend that GI and management practices should be optimized according to climate region and grassland type (C3, C4 or C3-C4 mixed).

To predict the response of C-rich soils to external change, models are needed that accurately
\nreflect the conditions of these soils. Estimation of Carbon in Organic Soils—Sequestration and
\nEmissions (ECOSSE) is a model that allows simulations of soil C and N turnover in both mineral and
\norganic soils using only the limited meteorological, land-use and soil data that is available at the
\nnational scale. Because it is able to function at field as well as national scales if appropriate input data
\nare used, field-scale evaluations can be used to determine uncertainty in national simulations. Here
\nwe present an evaluation of the uncertainty expected in national-scale simulations of Scotland, using
\ndata from the National Soil Inventory of Scotland. This data set provides measurements of C change
\nfor the range of soils, climates and land-use types found across Scotland. The simulated values show
\na high degree of association with the measurements in both total C and change in C content of the
\nsoil. Over all sites where land-use change occurred, the average deviation between the simulated
\nand measured values of percentage change in soil C was less than the experimental error (11% simulation
\nerror, 53% measurement error). This suggests that the uncertainty in the national-scale simulations
\nwill be ~11%. Only a small bias in the simulations was observed compared to the measured
\nvalues, suggesting that a small underestimate of the change in soil C should be expected at the
\nnational scale (–4%)

Updating and refining the N₂O emission factors (N₂O-EFs) are vital to reduce the uncertainty in estimates of direct N₂O emissions. Based on a database with 1151 field measurements across China, the N₂O-EFs were established via three approaches including the maximum likelihood method, a linear regression with an intercept and a linear regression with the intercept set to 0 using 70% of the observations. The remaining 30% of the observations were then used to evaluate the predicted N₂O-EFs. The third method had the highest <i>R</i>² of 0.39 and the best model efficiency of 0.38 with no significant bias, showing the best calculation efficiency. The results showed that the N₂O-EFs varied with agroregions, crops, and management patterns. The agroregions of Huang-Huai-Hai and Yangtze River had the higher N₂O-EFs in maize and wheat seasons than other regions, and the highest N₂O-EFs of 0.66-0.92% in the rice season was found in the South and Southwest agroregions. Both fertilizer types and water regimes had the remarkable effects on N₂O-EFs. Based on the best estimation by the selected method, direct N₂O emissions from China's crop cultivation were estimated to be 194 Gg N₂O-N with a 95% confidence interval of 180-208 Gg N₂O-N in the year 2016.

Food production is a major driver of greenhouse gas (GHG) emissions, water and land use, and dietary risk factors are contributors to non-communicable diseases. Shifts in dietary patterns can therefore potentially provide benefits for both the environment and health. However, there is uncertainty about the magnitude of these impacts, and the dietary changes necessary to achieve them. We systematically review the evidence on changes in GHG emissions, land use, and water use, from shifting current dietary intakes to environmentally sustainable dietary patterns. We find 14 common sustainable dietary patterns across reviewed studies, with reductions as high as 70-80% of GHG emissions and land use, and 50% of water use (with medians of about 20-30% for these indicators across all studies) possible by adopting sustainable dietary patterns. Reductions in environmental footprints were generally proportional to the magnitude of animal-based food restriction. Dietary shifts also yielded modest benefits in all-cause mortality risk. Our review reveals that environmental and health benefits are possible by shifting current Western diets to a variety of more sustainable dietary patterns.