Biofuels are a renewable alternative for reducing the climate impact of transport. Due to the versatility of biomass and complexity of economics and impacts, biofuels are part of a complex system, which is here analysed from a systems perspective. Several models are developed in order to assess...

We use worldwide satellite data to analyse how population size and density affect urban pollution. We find that density significantly increases pollution exposure. Looking only at urban areas, we find that population size affects exposure more than density. Moreover, the effect is driven mostly...