Scientific publications

Linking existing models to extend energy system and integrated assessment analysis is an increasingly common practice. Despite this, and unlike in the field of environmental and earth sciences, little attention has so far been paid to the details of it, to the trade-offs involved and the way in which the model linking affects the interpretation of the outcomes of the interlinked model system. Our aim in this paper is to first focus on a set of key technical and methodological problems that are common in model linking and suggest how these could be approached in different model linking contexts. We then further explore how model linking may affect the nature of the knowledge produced, and how this should be considered in the model linking process. Reflecting our literature driven assessment of the issues and possible solutions, we compile “a check list” to assist in the process of decision making for model linking.

Methane has been identified as the second-largest contributor to climate change, accounting for approximately 30% of global warming. Countries have established targets and are implementing various measures to curb methane emissions. However, our understanding of the trends in methane emissions and their drivers remains limited, particularly from a consumption perspective (i.e. accounting for all emissions along the entire global supply chain). This study investigates the most recent dynamics of methane emissions across 120 sectors from both production and consumption viewpoints in 164 countries. It also discusses the status of decoupling of production- and consumption-based methane emissions from economic growth. Our results indicate that there is no foreseeable slowdown in the momentum of global methane emissions growth. Only a few developed countries have managed to reduce both production- and consumption-based emissions while maintaining economic growth (i.e., strong decoupling) during the observed period (1990-2023). Global trade accounts for approximately 30% of global methane emissions, but major trade patterns are shifting from North-North and North-South to South-South countries, reflecting the increasing participating of developing countries in global supply chains. The study further reveals the changing drivers of global methane emissions from 1998 to 2023 in five-year intervals. It identifies that the reduction in emission coefficient (i.e., emissions per unit of output), driven by advancements in improved energy efficiency and cleaner production technologies, is the main determinant for reducing emissions over the observation period, partly offsetting the increasing effects from growth of final demand. Changes in demand structure have played a considerable role in the increase of emissions since 2008. This study enhances our understanding of the changes and drivers of methane emissions and supports countries in incorporating methane emissions into their climate mitigation strategies.

This study conducts a scenario analysis of global net-zero emissions by 2050 using two macroeconomic models with distinct theoretical foundations: E3ME (non-equilibrium) and GEM-E3 (equilibrium). The analysis quantifies the economic impacts of increasing climate policy ambition to meet the global 1.5 °C warming target and highlights key differences between the models in projecting GDP, employment, and sectoral transitions. The findings indicate that while economic outcomes of decarbonization may vary depending on the model paradigm used, the uncertainties in climate damage projections far exceed those of mitigation costs. By comparing the economic impacts of mitigation with potential losses from climate damages, the study finds that the costs of mitigation are lower and more predictable than the potential climate damage costs. Limiting warming to 1.5 °C yields net economic gains in almost all countries examined, while a 3 °C trajectory could trigger widespread losses. The study reinforces the need for decisive and immediate global mitigation efforts.

Formulating equitable climate policies should not overlook the challenges faced by less developed regions. African countries are at a crucial stage of economic development and deeper integration into global trade. Therefore, understanding their carbon footprints (i.e., consumption-based CO2 emissions) is essential for crafting a sustainable development pathway for Africa and developing comprehensive and fair climate policies. Here, we investigate consumption-based CO2 emissions in 55 African economics using a new Multi-Regional Input-Output model called “EMERGING” for 2015–2019; we also analyze the impacts of global trade participation on emissions, the decoupling status of emissions and economic, and hidden influencing factors. Results show that 65% of African countries experienced rapid growth in consumption-based emissions, with an average annual growth rate of 6.4%. Significantly, 87% of African countries are net emissions importers, predominantly attributed to their trade relations with other developing countries (i.e., South-South trade), a condition characterizing 68% of all trade interactions; The embodied carbon in imports is primarily concentrated in the transportation, petroleum refining, metal products, and machinery sectors. The decoupling analysis indicates that 15 countries strongly decoupled from production-based carbon emissions, and 14 from consumption-based; however, only 9 have concurrently achieved decoupling in both domains of emissions. Optimizing the carbon emission efficiency of final demand, particularly within the tertiary sector, is a key for successful decoupling and emissions reduction. The findings provide essential insights from consumption-based emissions that could guide more effective, targeted climate policies contributing to the mitigation of climate impacts and fostering sustainable development in African nations.

Cities are important actors in the global challenge of tackling climate change. They are not only responsible for the majority of emissions but also highly capable of taking action. An important precondition for effective climate mitigation is a city-level greenhouse gas emission inventory to guide mitigation action. Yet, most cities in developing countries, in particular African cities, lack that crucial information. This study aims to assess the current state of the development of African cities' emission inventories. A total of 270 inventories from 137 cities across 54 African countries were identified from 15 research articles, 5 reports, and 3 data platforms. We find the lack of standardized protocols results in inventories that are often not comparable, while data scarcity emerged as a common problem. We observe that insufficient engagement from local governments impedes the creation of a data-rich environment. Additionally, current inventory protocols do not fully address the data limitations faced by African cities, further hindering inventory development. To mitigate these challenges, multi-agent collaboration is essential to enhance the accounting capabilities of local governments. Developing refined protocols that consider data constraints is necessary. Moreover, advanced technologies may provide opportunities to overcome data bottlenecks.