If the global temperature rises by two degrees Celsius, the number of days with “uncomfortably high temperatures” in Austria will increase by 25%, researchers at the University of Oxford report in the journal “Nature Sustainability”. The cooling requirement is increasing proportionately, with Austria being among the top ten countries with the highest percentage increase worldwide. “These countries are dangerously unprepared for this shift,” the researchers said.
A team led by Jesus Lizana of Oxford University’s “Future of Cooling Programme” used mathematical models to calculate how much additional cooling would have to be done locally if global warming were not limited to 1.5 degrees Celsius (“Paris target” “), but two degrees Celsius reached. The most extreme temperatures would prevail in Central Africa. “People in Africa bear the brunt of a problem they did not cause,” the scientists said in a broadcast.
However, the biggest relative increase in days with cooling needs in a world warmed by two degrees Celsius will be experienced by people in previously colder regions of the world: Ireland leads the way with a 38% increase ahead of Switzerland and Great Britain. Britain (30 percent each), Norway, Finland and Sweden (28 percent each), Austria (25 percent), Canada, Denmark and New Zealand (24 percent each).
For their calculations, the scientists used what they say is a “widely used indicator” to quantify cooling requirements, so-called “degree days of cooling” (CDDs). This compares the average daily outdoor temperature at a location to a standard temperature (usually 18 degrees Celsius). Accordingly, for example, a day with an average outside temperature of 30 degrees Celsius has twelve CDDs.
conservative estimate
In particular, the top 10 countries identified in the study are traditionally configured for winter heating rather than summer cooling, according to the researchers. “At the moment, the buildings look like greenhouses: they don’t have external sun protection, they don’t have windows that can be darkened from the outside, they don’t have natural ventilation and they don’t have ceiling fans,” says Lizana. If you change building structures, you can reduce the additional need for air conditioning.
‘Without adequate measures for sustainable cooling, we will see a sharp increase in the use of energy intensive systems such as air conditioning’, explains Radhika Khosla (also from Uni Oxford). This can lead to a vicious circle: if fossil fuels are used for cooling, greenhouse gas emissions increase and accelerate global warming. “We would make the world warmer on the outside to feel cooler on the inside,” he says. Sustainable cooling measures are neglected in the climate adaptation strategies of the countries involved, criticize the researchers in the broadcast.
The scientists emphasized that the publication is a conservative estimate and does not take into account extreme events such as heat waves. That would astonish people beyond the average calculated increase. They will update attendees at the 2023 UN Climate Change Conference in Dubai in early December, where they plan to develop a “Global Cooling Commitment”. “To mitigate these effects, it is essential to keep warming below 1.5 degrees Celsius”, they say.
Service: https://doi.org/10.1038/s41893-023-01155-z