The knock-on effect of keeping cool in the Netherlands
The world is getting hotter, and societies are struggling to keep cool. It is no longer the case that extremely high temperatures and heatwaves are exclusively an issue of inherently warmer regions such as the tropics, the middle east, or sub-Saharan Africa. For example, in the Netherlands, heat waves are now happening much more frequently, with a longer duration and higher maximum temperatures. Studies show that excessive heat leads to lower productivity, decreased perceived cognitive performance by students, and even heat-related deaths. Of the deaths due to heat in the Netherlands, some 31% can be attributed to climate change, according to the National Institute for Public Health and the Environment (RIVM). This boils down to around 250 deaths per year. Studies predict that with unchanged policies and temperature trends, between 1,500 and 3,000 people will die from heat each year in 2050 in the Netherlands.
To combat the heat, many consumers install an air conditioner at home to cool the attic, bedroom, or living room. A study conducted in 2021 by Milieu Centraal, a climate change information foundation, finds that 1 in 5 Dutch households have at least one air conditioning unit. This number is still relatively low compared to countries like Japan and the US, where approximately 90% of households have at least one air conditioning unit. However, the trade association for climate control and refrigeration technology expects that families adopting an air conditioning unit will increase exponentially over the years to come (see figure 1). Below I provide some food for thought concerning what this trend implies for the climate and the future of energy-efficient buildings.
Global air conditioner stock, 1990-2050
According to Climate Works Foundation, at least 7% of global greenhouse gas (GHG) emissions come from cooling. A further increase in demand for space cooling would imply more GHG emissions due to two reasons. First, air-conditioners use so-called “F gases” (such as hydrofluorocarbons, or HFCs) as refrigerants. As the air conditioning units leak during use or on disposal, which is almost inevitable, these gases escape, damaging the environment. Second, the rising demand for cooling units puts enormous stress on current electricity systems in many countries, with the added trouble that heatwaves bring sudden spikes in use (see figure 2). The consequence is that spare capacity must be built to provide for summer peaks in power demand. As this excess capacity is only used in summer, countries are, to some extent, incentivized to provide it as cheaply as possible, using the cheapest and most polluting generation option, such as coal-fired plants. Overall, air conditioning units are rapidly becoming a significant contributor to climate change.
Share of global electricity demand growth to 2050
Source: International Energy Agency
In their seminal report titled “The future of staying cool,” the International Energy Agency (IEA) concludes that air conditioning units and electric fans are responsible for 20% of the total electricity used in buildings today. As the demand for space cooling increases, this percentage will increase even more. The market is responding with more energy-efficient air conditioning units and other innovative new methods such as SkyCool Systems, which do not use “F gases” as refrigerants. However, this alone will not be sufficient to keep energy use to a minimum. The floating office in Rotterdam is a prime example of how architects are trying to innovate by designing buildings that do not need air conditioning. The building is cooled by the river beneath it. However, most of these current strategies are still very expensive. More research needs to be done to develop more scalable and deployable solutions if we are serious about making buildings truly energy efficient and sustainable in the future.