Julie Rozenberg

Every country relies on a well-functioning road system. However, we do not have a clear understanding yet of the vulnerability of each of these road networks to different forms of disruption. In this study, we aim to better understand how road networks are affected by different disruptive events, to identify hotspots of road network vulnerabilities, and to better target where and what type of future investments can be made to develop more resilient networks. To do so, we developed a fully open-source modelling framework to expose over 200 country road systems across the world to random, local, and targeted disruption schemes. For each country, we assessed the impact of such disruptions on intra-country travel activities and regional accessibility. The results highlight the vulnerability of road systems in mountainous and small-island countries owing to the limited availability of alternative routes. Additionally, we find that, on average, low-income countries experience a collapse of road-system services with much fewer disruptions, relative to high-income countries, due to the lack of redundancy in their systems. While the value of goods and services disrupted may be higher in wealthier countries, the results highlight that from an equity perspective, transport infrastructure investments are more desired in low-income country networks.

The impacts of climate change on poverty depend on the magnitude of climate change, but also on socio-economic trends. An analysis of hundreds of baseline scenarios for future economic development shows that the drivers of poverty eradication differ across countries. In this chapter, two representative scenarios are selected from these hundreds, one optimistic and one pessimistic regarding poverty. Results from sector analyses of climate change impacts—in agriculture, health, and natural disasters—are introduced in the two scenarios. By 2030, climate change is found to have a significant impact on poverty. But the magnitude of these impacts depends on development choices. In the optimistic scenario with rapid, inclusive, and climate-informed development, climate change increases poverty by between 3 million and 16 million in 2030. The increase in poverty reaches between 35 million and 122 million if development is delayed and less inclusive in the pessimistic scenario.

To mitigate climate change, some governments opt for instruments focused on investment, like performance standards or feebates, instead of carbon prices. We compare these policies in a Ramsey model with clean and polluting capital, irreversible investment and a climate constraint. Alternative instruments imply different transitions to the same balanced growth path. The optimal carbon price minimizes the discounted social cost of the transition to clean capital, but imposes immediate private costs that disproportionately affect the current owners of polluting capital, in particular in the form of stranded assets. A phased-in carbon price can avoid stranded assets but still result in a drop of income for the owners of polluting capital when it is implemented. Second-best standards or feebates on new investment lead to higher total costs but avoid stranded assets, preserve the revenues of vested interests, and smooth abatement costs over individuals and time. These results suggest a trade-off between political feasibility and cost-effectiveness of environmental policies.