By capturing the fine structure of energy use, IIASA research reveals the need for targeted policy on energy access, illuminates a possible clash between access and climate, and shows that billions may be unprotected from heat stress.

To understand energy properly, you have to drill down into the details. IIASA teams have been developing their energy planning framework to do that, analyzing the demands from individual households and buildings.

“It’s important to look at the results of energy access and climate policies at the level of households – that usually gets lost in studies,” says Miguel Poblete Cazenave, Research Scholar in the Transformative Institutional and Social Solutions Research Group at IIASA.

Poblete Cazenave led a team studying how household energy use might be affected by economic change and climate policy. With the new IIASA modeling framework MESSAGEix-Buildings, they analyzed survey data to estimate behavioral preferences: how people in different regions are likely to spend their money on different energy-consuming end-uses such as food and entertainment, including detail on types of appliances such as refrigerators and heaters. The team then used these preferences to simulate how household energy demand is likely to change in a range of future scenarios.

They found that high economic growth alone will not achieve universal access. Even in the most optimistic growth scenarios, more than 10% of people in sub-Saharan Africa and South Asia still lack access to modern energy in 2050. This shows the need for policy targeted at energy access, such as investment in infrastructure and subsidies for poorer households.

The team also looked at whether climate action could be a barrier to access.

“There was an idea that mitigation policy will increase the price of electricity, making it unaffordable to poor households,” says Poblete Cazenave. “The simulations however show that the two goals are compatible after all. In scenarios with and without climate policies, access levels are similar – although still far short of UN access targets.”

It's also vital to understand how energy demand might unfold, to help inform climate policy. Another IIASA study looked at how demand for residential space heating and cooling could evolve under different socioeconomic pathways. A detailed housing model within MESSAGEix-Buildings accounts for the effect of new housing stock and household investment decisions, representing household income, building characteristics and energy efficiency in detail. The results show that efficiency improvements for energy should cut demand for heating (between 34 and 53% depending on the pathway), while energy demand for cooling is liable to rise sharply by 2050 (between 58 and 85%). The team is now looking at how demand might change under different climate policy scenarios and future temperature levels.

Not everyone will be able to keep cool. Another IIASA study projected the future cooling gap – the number of people exposed to heat stress but lacking access to air conditioning – using data about the availability of air conditioning today, and how that varies with average income, income inequality, and urbanization. The team found that in 2050, there could between 2 billion and 5 billion people unprotected from heat stress, mainly in South Asia, Sub-Saharan Africa, and Latin America, which would have grave consequences for human health. Megacities in the Global South, may be particularly vulnerable, and require strategies to adapt to growing heat stress in the future.

“This is only one example of a gap in our abilities to adapt to climate change,” says Marina Andrijevic, who led the study. “We cannot take it for granted that adaptation will simply happen.”



Poblete-Cazenave, M., Pachauri, S., Byers, E., Mastrucci, A., & van Ruijven, B. (2021). Global scenarios of household access to modern energy services under climate mitigation policy. Nature Energy 6 824-833. DOI: 10.1038/s41560-021-00871-0. []

Mastrucci, A., van Ruijven, B., Byers, E., Poblete-Cazenave, M., & Pachauri, S. (2021). Global scenarios of residential heating and cooling energy demand and CO2 emissions. Climatic Change 168 (3-4) e14. DOI: 10.1007/s10584-021-03229-3. []

Andrijevic, M., Byers, E., Mastrucci, A., Smits, J., & Fuss, S. (2021). Future cooling gap in shared socioeconomic pathways. Environmental Research Letters 16 (9) e094053. DOI: 10.1088/1748-9326/ac2195. []

Mastrucci, A., Byers, E., Pachauri, S., Rao, N., & van Ruijven, B. (2022). Cooling access and energy requirements for adaptation to heat stress in megacities. Mitigation and Adaptation Strategies for Global Change volume 27, 59. DOI: 10.1007/s11027-022-10032-7. []