Numbers always represent for science something well defined and quantifiable. A number doesn’t lie and, in some cases, it could make you shiver or at least make you think. During the first week of COP25, I participated in some side events on buildings’ energy efficiency, inside air cooling and future perspectives. I’ll try to summarize the most interesting concepts.
There is a strong relationship between energy and climate change, and we can think about it as a dog that bites its tail.
Greater energy consumption implies higher greenhouse gases emissions and thus global warming; at the same time, extreme weather conditions cause an increase of energy consumption, for example for cooling. The broad overview presented by Ian Hamilton, who is an Associate Professor at the University College of London Energy Institute, was particularly incisive. He talked about the relationship between energy and the building sector, and showed what future scenarios could be.
First of all, Ian underlined that in the past 10 years built-up areas have increased by almost 25%; meanwhile emissions, after a brief period of stagnation, have returned to grow for the past 3 years. With respect to global energy demand, the building sector has the lionshare with a 36%, which can be further broken down into non-residential (8%), residential (22%) and construction industry (6%). The emissions figure is similar, since the buildings sector globally contributes to 39% of emissions, coming in particular from direct residential (6%), indirect residential (11%), direct non residential (3%), indirect non residential (8%) and construction industry (11%).
By analyzing the data, the energy demand has slightly decreased for buildings’ heating, but it has increased for space cooling, also due to more frequent and intense heat waves. Citizens have two main options to protect themselves and live comfortably: thermal insulation and air conditioning. Environmentally-friendly and energy-saving consumers are less likely to buy new air conditioners. In particular, people concerned about the environment are more inclined to rely on thermal insulation. However, there is still a strong gap in the southern hemisphere and in developing countries, like China and India. The main problem is that thermal insulation requires a huge initial investment to provide a long-term benefit. On the other hand, air conditioning has a lower initial cost, but needs continuous maintenance and, above all, electricity -both of which are costly. Clearly it is not sustainable for the poor population, whose main need is food.
The most shocking figure is that, in 2018, global investments for building energy efficiency are still really low compared to what is spent for new buildings and renovation. Specifically, the speaker talked about 139 billion out of 4.5 trillion. Another big problem is that obsolete solutions are proposed on the market compared to those studied by the research. An example of this can be found in the air conditioning market.
In conclusion, all the speakers called for increased future investments to reduce energy consumption and greenhouse gas emissions. There are many possibilities for intervention, starting from lighting, water heating and air conditioning, to optimal thermal insulation systems. And let’s not forget the importance of individual good practices.