Heating and Cooling
Heating, water heating and cooling together account for ~50% of global building energy use and ~20% of total final energy. The biggest growth driver is air conditioning: cooling demand has nearly tripled since 2000 and is set to triple again by 2050. Heat pumps are the dominant electrification technology — sales doubled 2020-2023 in many markets.
Key insights
Cooling is the fastest-growing electricity demand
Air conditioning units installed worldwide rose from ~880M (2000) to ~2.0 billion (2024). Three-quarters of growth has been in emerging markets — India, Indonesia, Mexico, Brazil, Saudi Arabia. The IEA projects 5.6 billion ACs by 2050. Cooling currently uses ~10% of world electricity; without efficiency improvements, this share could double by 2050. Peak demand impacts are already dominant in southern US and Middle East power systems.
Heating is shifting from fossils to electric heat pumps
Heat pumps are 3-4× more efficient than resistive electric heating (they move heat, not generate it) and 1.5-2× more efficient than gas boilers. Norway, Sweden, Finland, Estonia have heat pumps in >40% of households. Italy, France, Germany are scaling fast. The US has lagged but heat pump sales overtook gas furnaces in 2022 for the first time. Building stocks turn over slowly — full electrification will take decades.
Cooling demand and energy poverty
Air conditioning is increasingly a survival need, not a comfort. Heatwave mortality (Europe 2003, India/Pakistan 2010s, China/Europe 2023) has scaled with climate change. But access is unequal: 90%+ of US households have AC; 5% of Indian rural households. The 'cooling gap' — where the heat stress is worst and access is weakest — is concentrated in the Sahel, India, and tropical Africa. IEA Future of Cooling reports this gap explicitly.
Air conditioners installed worldwide 2000–2050
Billion units, IEA outlook
Key Finding: More than tripling expected by 2050. The growth is concentrated in emerging-market households as incomes rise and climate warms.
Heat pump share of new heating sales — selected countries (2023)
% of new residential heat-source sales
Key Finding: Nordic countries lead; Italy and France are scaling fastest in 2022-23.
Methodology & caveats
End-use breakdown
Buildings energy use splits into: space heating (~35%), space cooling (~12%), water heating (~20%), lighting (~8%), appliances and other (~25%). Composition varies massively by climate — Nordic countries are 50-60% space heating; Singapore is 50% cooling. Aggregate global figures hide the climate-driven variance.
Efficiency vs absolute consumption
Building efficiency standards (insulation, windows, equipment efficiency) have improved per-unit consumption dramatically over 30 years. But total consumption rises as more square meters are built, more appliances installed, more cooling demanded. The efficiency-vs-quantity debate is central — most net-zero pathways require both efficiency gains and absolute reductions in some categories.
Refrigerant phase-down
HFC refrigerants (the working fluid in air conditioners and heat pumps) have thousands of times the global warming potential of CO₂. The Kigali Amendment (2016) commits to phasing them down. Replacement refrigerants (HFOs, propane, ammonia) are emerging but slower. The combined effect of expanding AC stock and refrigerant emissions could add 0.5°C of warming by 2100 if not managed.