Global scenarios of residential heating and cooling energy demand and CO2 emissions

Abstract

AbstractBuildings account for 36% of global final energy demand and are key to mitigating climate change. Assessing the evolution of the global building stock and its energy demand is critical to support mitigation strategies. However, most global studies lack granularity and overlook heterogeneity in the building sector, limiting the evaluation of demand transformation scenarios. We develop global residential building scenarios along the shared socio-economic pathways (SSPs) 1–3 and assess the evolution of building stock, energy demand, and CO2 emissions for space heating and cooling with MESSAGEix-Buildings, a modelling framework soft-linked to an integrated assessment framework. MESSAGEix-Buildings combines bottom-up modelling of energy demand, stock turnover, and discrete choice modelling for energy efficiency decisions, and accounts for heterogeneity in geographical contexts, socio-economics, and buildings characteristics.Global CO2 emissions for space heating are projected to decrease between 34.4 (SSP3) and 52.5% (SSP1) by 2050 under energy efficiency improvements and electrification. Space cooling demand starkly rises in developing countries, with CO2 emissions increasing globally by 58.2 (SSP1) to 85.2% (SSP3) by 2050. Scenarios substantially differ in the uptake of energy efficient new construction and renovations, generally higher for single-family homes, and in space cooling patterns across income levels and locations, with most of the demand in the global south driven by medium- and high-income urban households. This study contributes an advancement in the granularity of building sector knowledge to be assessed in integration with other sources of emissions in the context of global climate change mitigation and sustainable development.