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Building stock growth around the world drives extensive material consumption and environmental impacts. Future impacts will be dependent on the level and rate of socioeconomic development, along with material use and supply strategies. Here we evaluate material-related greenhouse gas (GHG) emissions for residential and commercial buildings along with their reduction potentials in 26 global regions by 2060. For a middle-of-the-road baseline scenario, building material-related emissions see an increase of 3.5 to 4.6 Gt CO2eq yr-1 between 2020–2060. Low- and lower-middle-income regions see rapid emission increase from 750 Mt (22% globally) in 2020 and 2.4 Gt (51%) in 2060, while higher-income regions shrink in both absolute and relative terms. Implementing several material efficiency strategies together in a High Efficiency (HE) scenario could almost half the baseline emissions. Yet, even in this scenario, the building material sector would require double its current proportional share of emissions to meet a 1.5 °C-compatible target. Building construction causes large material-related emissions which present a serious decarbonization challenge. Here, the authors show that the building material sector could halve emissions by increasing efficiency until 2060 but even then its emissions would be twice as high as needed to meet the 1.5 °C target.

The RCP2.6 emission and concentration pathway is representative of the literature on mitigation scenarios aiming to limit the increase of global mean temperature to 2°C. These scenarios form the low end of the scenario literature in terms of emissions and radiative forcing. They often show negative emissions from energy use in the second half of the 21st century. The RCP2.6 scenario is shown to be technically feasible in the IMAGE integrated assessment modeling framework from a medium emission baseline scenario, assuming full participation of all countries. Cumulative emissions of greenhouse gases from 2010 to 2100 need to be reduced by 70% compared to a baseline scenario, requiring substantial changes in energy use and emissions of non-CO 2 gases. These measures (specifically the use of bio-energy and reforestation measures) also have clear consequences for global land use. Based on the RCP2.6 scenario, recommendations for further research on low emission scenarios have been formulated. These include the response of the climate system to a radiative forcing peak, the ability of society to achieve the required emission reduction rates given political and social inertia and the possibilities to further reduce emissions of non-CO 2 gases.

While material resources form a critical foundation for human society, their extraction, processing, and use are also a major driver of environmental pressures. Understanding future material consumption is therefore vital. This study presents a comprehensive assessment of future global bulk material consumption, covering metals (steel, aluminium, copper) and non-metallic minerals (cement, sand, limestone, clay). We use the Integrated Assessment Model IMAGE, combined with a stock-driven dynamic material flow analysis model, to provide full coverage of global and regional material flows. We project material consumption for a current-policy baseline, a climate policy scenario (1.5 °C) and two scenarios that add resource efficiency measures on top of the climate policies. Following current policies, by 2050 consumption of steel, aluminium, copper are expected to increase by 25%, 97%, and 84% respectively. Cement, sand, limestone and clay increase by 5%–23%. The climate policy scenario shows increases compared to baseline across all metals and cement, especially in the 2030/2040 period driven by required electricity and vehicle system transformations. The largest relative increase is projected for copper and aluminium, i.e. 22% and 9%, compared to current policies in 2050. Combining climate policies and resource efficiency, however, can reduce the use of non-metallic minerals below current levels and stabilize steel consumption, thus enabling growth in housing, transport, and decarbonized electricity systems. The most effective measures are related to efficiency and sufficiency measures (such as building with less material and reducing floor space). Although copper and aluminium consumption continue to rise across all scenarios, this can be significantly limited by resource efficiency measures. Overall, our findings highlight that resource efficiency policies are critical to managing the additional material consumption induced by climate policy.

The ongoing energy transition from fossil fuels to renewables is increasing the demand for materials, particularly metals. As fossil fuel infrastructure, such as refineries, tankers, pipelines, and ships, is phased out, this obsolete infrastructure could serve as an urban mine, supplying secondary materials like steel, aluminium, and copper. However, the extent to which these materials can meet future needs remains unclear and is often overlooked. Here we develop the global dynamic fossil fuel material model to quantify material stocks embedded in fossil fuel infrastructure and project secondary material availability through 2050 under the Shared Socioeconomic Pathway 2 (SSP2) baseline and 2-degree Celsius (2D) scenarios. Our findings indicate that material demand for new infrastructure continues to grow under the baseline scenario and exceeds recoverable volumes. Even under the 2D scenario, the surplus of recovered metals remains insufficient to meet the growing material requirements of renewable energy technologies. Material demand for renewable energy technology under the medium emissions and two-degree Celsius scenarios exceeds the amount recovered from decommissioned fossil fuel infrastructure, according to an analysis that uses a dynamic fossil fuel material model.

Limiting climate change to 2 °C with a high probability requires reducing cumulative emissions to about 1600 GtCO 2 over the 2000–2100 period. This requires unprecedented rates of decarbonization even in the short-run. The availability of the option of net negative emissions, such as bio-energy with carbon capture and storage (BECCS) or reforestation/afforestation, allows to delay some of these emission reductions. In the paper, we assess the demand and potential for negative emissions in particular from BECCS. Both stylized calculations and model runs show that without the possibility of negative emissions, pathways meeting the 2 °C target with high probability need almost immediate emission reductions or simply become infeasible. The potential for negative emissions is uncertain. We show that negative emissions from BECCS are probably limited to around 0 to 10 GtCO 2 /year in 2050 and 0 to 20 GtCO 2 /year in 2100. Estimates on the potential of afforestation options are in the order of 0–4 GtCO 2 /year. Given the importance and the uncertainty concerning BECCS, we stress the importance of near-term assessments of its availability as today’s decisions has important consequences for climate change mitigation in the long run.

The foundations of today’s societies are provided by manufactured capital accumulation driven by investment decisions through time. Reconceiving how the manufactured assets are harnessed in the production–consumption system is at the heart of the paradigm shifts necessary for long-term sustainability. Our research integrates 50 years of economic and environmental data to provide the global legacy environmental footprint (LEF) and unveil the historical material extractions, greenhouse gas emissions, and health impacts accrued in today’s manufactured capital. We show that between 1995 and 2019, global LEF growth outpaced GDP and population growth, and the current high level of national capital stocks has been heavily relying on global supply chains in metals. The LEF shows a larger or growing gap between developed economies (DEs) and less-developed economies (LDEs) while economic returns from global asset supply chains disproportionately flow to DEs, resulting in a double burden for LDEs. Our results show that ensuring best practice in asset production while prioritizing well-being outcomes is essential in addressing global inequalities and protecting the environment. Achieving this requires a paradigm shift in sustainability science and policy, as well as in green finance decision-making, to move beyond the focus on the resource use and emissions of daily operations of the assets and instead take into account the long-term environmental footprints of capital accumulation.

While most long-term mitigation scenario studies build on a broad portfolio of mitigation technologies, there is quite some uncertainty about the availability and reduction potential of these technologies. This study explores the impacts of technology limitations on greenhouse gas emission reductions using the integrated model IMAGE. It shows that the required short-term emission reductions to achieve long-term radiative forcing targets strongly depend on assumptions on the availability and potential of mitigation technologies. Limited availability of mitigation technologies which are relatively important in the long run implies that lower short-term emission levels are required. For instance, limited bio-energy availability reduces the optimal 2020 emission level by more than 4 GtCO₂eq in order to compensate the reduced availability of negative emissions from bioenergy and carbon capture and storage (BECCS) in the long run. On the other hand, reduced mitigation potential of options that are used in 2020 can also lead to a higher optimal level for 2020 emissions. The results also show the critical role of BECCS for achieving low radiative forcing targets in IMAGE. Without these technologies achieving these targets become much more expensive or even infeasible.

Limiting climate change to 2 degree C with a high probability requires reducing cumulative emissions to about 1600 GtCO sub(2) over the 2000-2100 period. This requires unprecedented rates of decarbonization even in the short-run. The availability of the option of net negative emissions, such as bio-energy with carbon capture and storage (BECCS) or reforestation/afforestation, allows to delay some of these emission reductions. In the paper, we assess the demand and potential for negative emissions in particular from BECCS. Both stylized calculations and model runs show that without the possibility of negative emissions, pathways meeting the 2 degree C target with high probability need almost immediate emission reductions or simply become infeasible. The potential for negative emissions is uncertain. We show that negative emissions from BECCS are probably limited to around 0 to 10 GtCO sub(2)/year in 2050 and 0 to 20 GtCO sub(2)/year in 2100. Estimates on the potential of afforestation options are in the order of 0-4 GtCO sub(2)/year. Given the importance and the uncertainty concerning BECCS, we stress the importance of near-term assessments of its availability as today's decisions has important consequences for climate change mitigation in the long run.

This paper shows the importance of including region-specific circumstances in long-term climate change mitigation strategies, by example of a modeling exercise of the transport sector. Important emission reduction options in the transport sector include biofuels, electric vehicles and efficiency standards. The most effective combination of these options depends, among others, on the availability of biofuels, the effectiveness of efficiency standards, and the (expected) emission intensity of the power sector—all of which differ between regions. Differences in climate policies between regions influence these factors. For instance, fuel efficiency standards slowdown the long-term transition in regions where plugin hybrid electric cars compete with gasoline cars (such as the USA or Europe) by decreasing the costs for driving gasoline costs and therefore in fact increase long-term emissions. Another example is that promoting electric vehicles is less effective in regions which are expected to rely heavily on fossil fuels for power generation, such as South Africa, China and India. Based on these findings from the TIMER energy model, we introduce an indicative region-specific framework for assessing mitigation strategies for the transport sector up to 2050, for different ambition levels of climate policy.