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This year, the world experienced its hottest summer ever. In July — officially the hottest month ever recorded — more than 80 per cent of the world’s population was exposed to levels of heat made significantly more likely by climate change.  And this is just the start as temperatures rise globally, leaving us with a challenge: how can we stay cool without becoming overly reliant on energy-intensive and climate-polluting air conditioners? 

This is one of the topics Climate Catalyst explored as a potential campaign topic for our next campaign in Europe. 

At Climate Catalyst we work to strengthen collaboration and mobilise new actors on pivotal climate challenges. As part of this, we bring together key experts – as well as new actors – to help us find the climate challenges where progress to date has been limited, but where there is an urgency to take action to reduce greenhouse gas emissions. 

We want to work together, to build a just and prosperous world where global temperature rise is held below 1.5C. 

In early 2023, we began our work to identify our next area of focus. Through our early research and conversations with experts, we identified cooling buildings as a key challenge. As the world heats, demand for technologies to keep us cool will increase exponentially. But, and here comes the challenge, right now, those technologies are themselves fuelling worsening climate change, largely powered by the dangerous fossil fuels which are fuelling the climate crisis. Ultimately, our research took us in another direction, and in 2024 we will be launching new work in Europe aimed at decarbonising the aviation sector. 

We have a commitment to learning as one of our core values. With this in mind, we want to share our initial learnings from our scoping on this topic. 

Increased urbanisation and ageing populations, combined with more heat extremes are a huge and increasing risk to human health globally. (IPCC). 

  • Our exposure to extreme heat, and the impact it has on our health is dependant on two key factors: the level of greenhouse gases emitted into the atmosphere, fuelling more frequent extreme heat events, and the measures put in place to lessen their impact and increase our resilience to them (for example streets with more trees  and white roofs). 
  • In the past 50 years, almost 150 000 people in Europe lost their lives due to extreme temperatures (WHO, 2022). The EU could experience over 100 000 additional annual heat fatalities by the end of the century under a high warming scenario (ECHO, 2021). 

Temperature rises and extreme hot days, caused by climate change, are directly increasing the need for cooling. This in turn is increasing the use of fossil fuels to meet  the increased electricity load, which is contributing, in turn, to more climate change. 

Electricity use – often met by fossil fuels – is the main contributor to the climate impact of cooling in buildings. 

  • Air conditioners (ACs) themselves only increase greenhouse gas emissions when leakage or improper disposal of refrigerants occurs. However, when this does occur, these refrigerants are extremely powerful greenhouse gases (such as hydrofluorocarbons) that significantly contribute to climate change. 
  • Space cooling, such as cooling buildings, can account for a large share of peak electricity demand. This places stress on the power system, especially during periods of extreme heat. Cooling demand typically jumps during a heatwave, placing greater demands on the power system. Meanwhile, the reliability of these systems can be further undermined by hot equipment increasing the risk of outages. For example, the power produced by solar panels and gas turbines can be reduced at very high ambient temperatures. Electricity networks can also be affected, as high demand and high temperatures heat up power lines, impairing their performance.
  • Meeting electricity peak load is expensive. It requires the electricity system to install and maintain large amounts of capacity that can be ramped up quickly at short notice, even though a significant portion might only be used for a few hours or days each year – if at all.
  • In France alone, the carbon dioxide (CO2) emissions associated with the operation of air conditioning systems can be estimated at approximately 0.9 million tonnes per year. That’s about 4.5 per cent of total emissions generated by electricity production in France. 
  • During the 2019 heatwave in France, the country’s transmission system operator, RTE, announced record highs for energy consumption that summer, saying that it was related to the use of air conditioners and fans. For each degree above normal seasonal temperatures, RTE observed increases in energy consumption of 500MW – equivalent to the entire electricity consumption of the city of Bordeaux.

There are already a number of policy solutions in place. Policy in all countries should focus on two main areas: increasing the energy efficiency of new cooling equipment that is offered for sale and the thermal performance of buildings that need to be cooled. 

  • Most regulations include minimum energy performance standards (MEPS) and building energy codes; incentives such as taxes and subsidies; and information measures including equipment energy labels and capacity-building programmes. But national governments also need to support energy efficiency policies at the local level, where investment decisions are taken and implemented.
  • Most of the major cooling markets (including in the EU) today have mandatory MEPS, although the required efficiency levels are typically far below those of the most efficient products available.  Most air conditioners sold are 2-3 times less efficient than the best available on the market. Additionally, improving the installation of new equipment and monitoring and maintenance of existing equipment could deliver electricity savings of up to 20%. This is also where cooling tech could create jobs. 

Of course, we also need to reduce demand for cooling through improved building design and construction, management, shifts in user behaviour, and use of green and more reflective surfaces. 

  • Property developers should shift to more innovative approaches, such as passive cooling, which involves optimising building design in order to capture natural wind flows, accelerate the movement of air through spaces, and make use of building orientation and exterior shading. After all, incorporating this into the building design at the outset is much cheaper than retrofitting later on. 
  • An example of change is Spain, which published new rules in January 2023 stipulating that no business will be allowed to cool its interior below 27 degrees Celsius (81 degrees Fahrenheit) or to heat it above 19 degrees Celsius (66 degrees Fahrenheit) in winter. Such measures will be in place until November 2023 (Bloomberg, 2022).

Other drivers for decarbonisation of the cooling sector include using renewable heat or waste heat,  thermal energy storage for cooling technologies and reversible heat pumps, which can produce both high and low temperatures.

  • Cooling accounts for as much as 30 to 50 per cent of total energy consumption in data centres, and the growth in the number of data centres will lead to increased energy usage and CO2 emissions in future years. Consequently, it is high time for a switch to sustainable cooling so this could be an impactful campaign angle.
  • Latest figures published on the European Heat Pump Association website show huge growth in heat pump sales across Europe. Germany saw a 53 per cent increase in 2022, with about 236,000 heat pumps sold for heating buildings. Similarly, Norway, where about two-thirds of households now have a heat pump, has seen a 25 per cent increase in sales and, in Finland, where the heat pump market is very mature, sales grew by 50 per cent in 2022. 
  • Another option is the expansion and modernisation of efficient District Heating and Cooling (DHC). Here, costs can also be lower thanks to economies of scale, especially if it makes use of a low-cost source of energy, such as industrial excess heat or geothermal energy. Advanced DHC networks can pair heating and cooling services to increase the net efficiency and flexibility of the entire energy system, for example by boosting district heat for water heating by capturing the heat in cooling return lines. Buildings – such as hospitals, shopping malls and data centres which need cooling energy all year round – represent the largest target group for district cooling. 

Despite this progress, policy needs to be made more ambitious to create the rate of change needed. And, in the longer term, policy could also play a role in encouraging the development of new technologies that promise to supply cooling services in a more sustainable way.

  • The European Commission’s current proposal to revise the EU’s energy efficiency directive names clean cooling technology as a priority, but it is far from becoming law.  
  • The adoption of the ambitious provisions on heating and cooling included in the Fit for 55 Package – notably the renewable energy directive, the energy efficiency directive, the emissions trading system and the energy performance of buildings directive – as well as new State aid rules will in principle provide an easier access to aid for modernisation and deployment of DHC systems.

Ultimately we concluded that Climate Catalyst is better able to contribute to the climate challenge by focusing on aviation, but if you are interested in working on this topic, there are great organisations and coalitions to explore. We would be happy to share any research, learning or mapping completed with anyone exploring this as a topic for future work. 

Below is a shortlist of some useful resources:

  • Heating and Cooling Strategy 2016: sets out actions and tools to ensure that the heating and cooling sector contributes to the EU objective of climate neutrality by 2050 (but is deemed no longer fit for purpose or reflective of current social, political and environmental landscape in EU). 
  • REPowerEU is the EU’s response to global energy market disruption caused by Russia’s invasion of Ukraine and the climate crisis through energy savings, diversification of energy supplies, and accelerated roll-out of renewable energy to replace fossil fuels in homes, industry and power generation.
  • The Renovation Wave presented in October 2020 set out measures aiming to at least double the annual energy renovation rate by 2030. 
  • The Energy Performance of Buildings Directive (EPBD) is an essential element of the Renovation Wave Strategy. It upgrades the existing regulatory framework to reflect higher ambitions and more pressing needs in climate and social action.”
  • New European Bauhaus connects the European Green Deal to our daily lives and living spaces. There is a new proposed Horizon Mission on the New European Bauhaus with a focus on research and innovation solutions, the proposed mission would aim to transform neighbourhoods across Europe for the better, making them beautiful, sustainable and inclusive. 
  • SBTi’s Buildings Project develops science-based target-setting methodologies, tools and guidance for companies in the building sector and other stakeholders.
  • World Green Buildings Council Commitment was developed to recognise and promote advanced climate leadership action from businesses, organisations, cities and subnational governments in decarbonising the built environment, to inspire others to take similar action and remove barriers to implementation.
  • There are already a number of international collaborations highlighting cooling, such as the Clean Cooling Coalition, the Cool Coalition, the Biarritz Pledge for Fast Action on Efficient Cooling, the World Bank Sustainable Cooling Initiative and the Sustainable Cooling Innovation Program.

About the Author

Saskia Heijnen

Head of Networks and Partnerships.
As a believer in the power of collaboration, Saskia has spent her career dedicated to building networks and communities of practice in research, civil society and international development.

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