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Bouwman, Lex

Publications and source records attributed to Bouwman, Lex.

Chapter 22 - Pathways Toward Sustainable Development

Model-based scenario analysis can help in identifying ways to achieve the environmental targets of the Sustainable Development Goals (SDGs) and related multilateral environmental agreements (MEAs) (well established). Target-seeking scenarios provide insight into the required level of effort, promising measures, and possible synergies and trade-offs between these measures and a range of targets. The usefulness of scenarios can be illustrated by the successful use of such scenarios in the literature on climate policy. Scenarios can be used to explore different pathways for achieving long-term targets and provide insights into the costs and benefits of these pathways. There are important interrelations (synergies and trade-offs) between the achievement of the various SDGs and related MEAs.. This means that strategies that aim to achieve sets of targets will have to take account for these interrelations. At the moment, scenarios that explore the fulfilment of a large set of SDG targets simultaneously are mostly lacking. An assessment of possible pathways must therefore rely on more narrowly focused scenarios in the literature. This does lead to a higher level of uncertainty and some clear knowledge gaps. {22.2}

Van Vuuren, Detlef↗

Phosphorus in agricultural soils: drivers of its distribution at the global scale

Phosphorus (P) availability in soils limits crop yields in many regions of the world, while excess of soil P triggers aquatic eutrophication in other regions. Numerous processes drive the global spatial distribution of P in agricultural soils, but their relative roles remain unclear. Here, we combined several global datasets describing these drivers with a soil P dynamics model to simulate the distribution of P in agricultural soils and to assess the contributions of the different drivers at the global scale. We analyzed both the labile inorganic P (P ILAB ), a proxy of the pool involved in plant nutrition and the total soil P (P TOT ). We found that the soil biogeochemical background (BIOG) and farming practices (FARM) were the main drivers of the spatial variability in cropland soil P content but that their contribution varied between P TOT vs P ILAB . Indeed, 97% of the P TOT spatial variability could be explained by BIOG, while BIOG and FARM explained 41% and 58% of P ILAB spatial variability, respectively. Other drivers such as climate, soil erosion, atmospheric P deposition and soil buffering capacity made only very small contribution. Lastly, our study is a promising approach to investigate the potential effect of P as a limiting factor for agricultural ecosystems and for global food production. Additionally, we quantified the anthropogenic perturbation of P cycle and demonstrated how the different drivers are combined to explain the global distribution of agricultural soil P.

54 ENVIRONMENTAL SCIENCES↗

Future air pollution in the Shared Socio-economic Pathways

Emissions of air pollutants such as sulfur and nitrogen oxides and particulates have significant health impacts as well as effects on natural and anthropogenic ecosystems. These same emissions also can change atmospheric chemistry and the planetary energy balance, thereby impacting global and regional climate. Long-term scenarios for air pollutant emissions are needed as inputs to global climate and chemistry models, and for analysis linking air pollutant impacts across sectors. In this paper we present methodology and results for air pollutant emissions in Shared Socioeconomic Pathways (SSP) scenarios. We first present a set of three air pollution narratives that describe high, central, and low pollution control ambitions over the 21 st century. These narratives are then translated into quantitative guidance for use in integrated assessment models. We provide an overview of pollutant emission trajectories under the SSP scenarios. Pollutant emissions in these scenarios cover a wider range than the scenarios used in previous international climate model comparisons. Furthermore, the SSP scenarios provide the opportunity to access a more comprehensive range of future global and regional air quality outcomes.

54 ENVIRONMENTAL SCIENCES↗