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We present a global dataset of anthropogenic carbon dioxide (CO2) emissions for 343 cities. The dataset builds upon data from CDP (187 cities, few in developing countries), the Bonn Center for Local Climate Action and Reporting (73 cities, mainly in developing countries), and data collected by Peking University (83 cities in China). The CDP data being self-reported by cities, we applied quality control procedures, documented the type of emissions and reporting method used, and made a correction to separate CO2 emissions from those of other greenhouse gases. Further, a set of ancillary data that have a direct or potentially indirect impact on CO2 emissions were collected from other datasets (e.g. socio-economic and traffic indices) or calculated (climate indices, urban area expansion), then combined with the emission data. We applied several quality controls and validation comparisons with independent datasets. The dataset presented here is not intended to be comprehensive or a representative sample of cities in general, as the choice of cities is based on self-reporting not a designed sampling procedure.

The political will to reduce global GHG emissions has largely contributed to increased global biofuel production and trade. The expanding cultivation of energy crops may drive changes in the terrestrial ecosystems such as land cover and biodiversity loss. When biomass replaces fossil energy carriers, sustainability criteria are therefore crucial to avoid adverse impacts and ensure a net positive GHG balance. The European Union has set mandatory sustainability criteria for liquid biofuels in its Renewable Energy Directive (RED) 2009/28/EC to ensure net positive impacts of its biofuel policy. The adoption of sustainability criteria in other world regions and their extension to solid and gaseous biomass in the EU is ongoing. This paper examines the effect of the EU RED sustainability criteria on the availability of biomass resources at global and regional scale. It quantifies the relevance of sustainability criteria in biomass resource assessments taking into account the criteria's spatial distribution. This assessment does not include agricultural and forestry residues and aquatic biomass. Previously unknown interrelations between sustainability criteria are examined and described for ten world regions. The analysis concludes that roughly 10% (98.5 EJ) of the total theoretical potential of 977.2 EJ occurs in areas free of sustainability concerns.Keywords: biodiversity, biomass potential, European renewable energy directive, GHG balance, liquid-biofuels, sustainable energy IntroductionTo mitigate climate change, the reduction of greenhouse gas (GHG) emissions is one of the key challenges for the coming decades (IPCC, 2007). Due to technological path dependencies and a current lack of alternatives, biofuels play a vital role for GHG savings in the transport sector (Gibson et al., 2011). Over the past decade, largely politically driven support has already led to an exponential increase in global production and trade of liquid and solid biofuels (Lamers et al., 2011(Lamers et al., , 2012. This trend is bound to continue, e.g., the European Union's (EU) target of a 20% share of renewable energy in final transport energy supply by 2020. The vast majority of this will be supplied by biofuels (Beurskens & Hekkenberg, 2010). Similar targets are set in the US and China (Ren21, 2011). In the light of past production expansions the potential future demand for biofuels has raised concerns over the sustainability, climate change mitigation potential and availability of the feedstock (Fargione et al., 2008;Melillo et al., 2009;Searchinger, 2010). Current biofuel policies incorporate limited control mechanisms for the mobilization of specific biomass resources to satisfy the growing demand. The European Renewable Energy Directive (RED) 2009/28/EC (EC, 2009) has been among the first to define several sustainability criteria covering land use change, biodiversity, and GHG emissions (Rfa, 2008;Searchinger, 2008; EC, 2009;Dehue & Van De Staaij, 2010;Fritsche, 2010). The RED criteria currently apply solely to liquid biofuels...

Non-technical summaryGlobal land is turning into an increasingly scarce resource. We here present a comprehensive assessment of co-occuring land-use change from 2000 until 2010, compiling existing spatially explicit data sources for different land uses, and building on a rich literature addressing specific land-use changes in all world regions. This review systematically categorizes patterns of land use, including regional urbanization and agricultural expansion but also globally telecoupled land-use change for all world regions. Managing land-use change patterns across the globe requires global governance.

Urban street space is increasingly contested. However, it is unclear what a fair street space allocation would look like. We develop a framework of ten ethical principles and three normative perspectives on street space -streets for transport, streets for sustainability, and streets as place -and discuss 14 derived street space allocation mechanisms. We contrast these ethically grounded allocation mechanisms with real-world allocation in 18 streets in Berlin. We find that car users, on average, had 3.5 times more space available than non-car users. While some allocation mechanisms are more plausible than others, none is without normative implications. Without exception, all principles suggest that on-street parking for cars is difficult to justify, and that more space should be allocated to cycling. We argue that street space fairness principles should be systematically integrated into urban and transport planning.