Approaching national climate targets in China considering the challenge of regional inequality.

Achievement of national climate targets and the corresponding costs would entirely depend on regional actions within the country. However, because of substantial inequalities and heterogeneities among regions, especially in developing economies, aggressive or uniform actions may exacerbate inequity and induce huge economic losses, which in turn challenges the national climate pledges. Hence, this study extends prior research by proposing economically optimal strategies that can achieve national climate targets and ensure the greatest local and national benefits as well as regional equality. Focusing on the biggest developing country China, we find this strategy can avoid up to 1.54% of cumulative GDP losses for approaching carbon neutrality, and more than 90% of regions would obtain economic gains compared either with existing independently launched targets or with the uniform strategy that all regions achieve peak carbon emissions before 2030. We also provide optimal carbon mitigation pathways to regional peak carbon, carbon intensity and energy consumption.

The global mismatch between equitable carbon dioxide removal liability and capacity.

Limiting climate change to 1.5°C and achieving net-zero emissions would entail substantial carbon dioxide removal (CDR) from the atmosphere by the mid-century, but how much CDR is needed at country level over time is unclear. The purpose of this paper is to provide a detailed description of when and how much CDR is required at country level in order to achieve 1.5°C and how much CDR countries can carry out domestically. We allocate global CDR pathways among 170 countries according to 6 equity principles and assess these allocations with respect to countries' biophysical and geophysical capacity to deploy CDR. Allocating global CDR to countries based on these principles suggests that CDR will, on average, represent ∼4% of nations' total emissions in 2030, rising to ∼17% in 2040. Moreover, equitable allocations of CDR, in many cases, exceed implied land and carbon storage capacities. We estimate ∼15% of countries (25) would have insufficient land to contribute an equitable share of global CDR, and ∼40% of countries (71) would have insufficient geological storage capacity. Unless more diverse CDR technologies are developed, the mismatch between CDR liabilities and land-based CDR capacities will lead to global demand for six GtCO2 carbon credits from 2020 to 2050. This demonstrates an imperative demand for international carbon trading of CDR.

Global environmental inequality: Evidence from embodied land and virtual water trade.

The trade-off between economic growth and environmental conservation is the focus of national environmental management. Previous studies have proved that global trade can bring both economic benefits and environmental costs to all countries. However, for different countries, it is not clear whether the environmental costs match their economic benefits in global trade. Also, whether the global trade exacerbates or mitigates the uneven distribution of natural resources among countries need to be further investigated. This study aims to fill these research gaps by providing evidence of global environmental inequality from land and water perspective, thus inspire new thinking on the optimization of global trade patterns. We construct an environmental inequality index based on the world Multi-Regional Input-Output (MRIO) model, and perform a case study for land and water. Results show that most of countries with low per capita land resources are net importers of embodied land, while many countries with extreme water shortages are net exporters of virtual water, such as India, Pakistan, Iran and Egypt, indicating that the global trade encourages the optimal distribution of land resources but exacerbates the uneven distribution of water resources. The environmental cost of developed countries is much lower than that of developing countries compared to their economic gains from global trade, and the inequality of virtual water trade is higher than that of embodied land trade. High-income countries mainly export high value-added products with low environmental costs, while developing countries are just the opposite. We suggest that due to the lack of a unified global natural resource market, resource tax may be an effective means to reduce global environmental inequality and resource mismatch, and policies aimed at reducing environmental inequality can help achieve coordinated management of land and water resources.