“The article we present today is by Davide Dell’Oro, SJ, an Italian Jesuit committed to promoting ecological justice and environmental sustainability as an integral part of his mission.
Fr. Dell’Oro is a member of the Eco-Team of the Jesuit Euro-Mediterranean Province and is currently a visiting scholar at the Polytechnic University of Milan, where he is dedicated to advanced research on building decarbonization and climate change mitigation strategies. He also collaborates with the Centre for Integrated Facility Engineering (CIFE) at Stanford University in innovative studies on the topic. With a doctorate in Building Systems and Processes Engineering and a Master’s Degree in Civil Engineering-Architecture from Polytechnic University of Milan, his academic expertise is complemented by a deep spiritual inspiration that orients his commitment and mission.
In the article, Fr. Dell’Orro highlights how the decarbonization of buildings represents a concrete approach to reducing greenhouse gas emissions, recalling the importance of being actively involved in this global challenge. This call to action is nourished by deep faith, which prompts us to work for the care of creation and to protect the most vulnerable, recognizing the moral urgency of caring for our Common Home. The author encourages us to embrace practical solutions and believe that change is possible, turning ecological responsibility into a mission of hope and living faith”.
Carla Bellone
Assistant to the Secretary for the Service of Faith
The climate is changing globally at an unprecedented rate. The Global Precipitation Climatology Centre (GPCC) continues to record increasing rainfall and lasting dry spells each year. In Italy alone, extreme events increased by 485% in 2024 compared to 2015. Floods, tornados, heat waves, and droughts caused severe damage and threatened people’s lives all over the globe last year. The most recent report from the Internal Displacement Monitoring Center (IDMC) stated that, during 2023, there were over 20 million weather-related internal displacements. The previous year, the number was even higher, close to 32 million. Can something be done to prevent this from happening again and again?
Most scientists agree that human-produced greenhouse gases (GHGs) are causing climate change. Humanity stands at a crucial crossroads: it must lower its GHG emissions before climate change reaches its tipping point and becomes irreversible for centuries. Now, more than ever, our society must commit to embracing a more sustainable development that respects human lives, especially the poorest ones, and the environment.
Although there has been progress in climate action, such as the EU reducing GHG emissions by over 30% since 1990, the United Nations Environmental Programme (UNEP) reports that the measures adopted by countries since the 2015 Paris Agreement have proven insufficient to decrease global GHG emissions. The growing gap from GHG emission targets, combined with the disappointing outcomes from the Conferences of Parties, led to skepticism about successfully containing climate change. Many are arguing that, at this point, humanity should adapt to live in a hotter world instead. Some are even planning to colonize Mars and the Moon, maybe judging life on Earth as doomed already.
We cannot but wonder: if climate change won’t be contained, what will become of those who cannot adapt or escape to another planet? Is there any hope left for stopping this crisis?
If political negotiations and lack of global cooperation have made “top-down” approaches to climate change less effective and quite frustrating for many, “bottom-up” actions such as building decarbonization may represent untapped possibilities to curb GHG emissions.
Buildings are responsible for 6% of global GHG emissions, according to the Sixth Assessment Report (AR6) from the Intergovernmental Panel on Climate Change (IPCC). Their contribution to GHG emissions may seem marginal compared to others, such as power production (26%) or transportation (15%). However, when factoring in indirect and embodied GHG emissions tied to buildings and building construction, their share skyrockets to potentially over 30% of total GHG emissions. It is evident that, to mitigate climate change effectively, we must commit to decarbonizing our buildings. So, what does it mean to decarbonize buildings? Is it something within our reach?
Building decarbonization means reducing and potentially eliminating the GHG emissions generated by buildings at each stage of their life cycle. GHG emissions from buildings may fall into two types. The emissions produced by operating a building are known as operational carbon, while the GHG emissions generated during the rest of its life cycle are called embodied carbon. Thanks to technological advancements, it is possible to design and construct Nearly-Zero Emission Buildings (NZEB), which are newly constructed buildings that have zero operational and minimal embodied carbon. These buildings are highly energy-efficient, operate solely on carbon-free energy, and result from optimized design-construction processes that minimize waste from construction materials.
Decarbonizing existing buildings can present challenges due to data unavailability, high retrofit costs, and building constraints. At present, turning an existing building into a NZEB requires high upfront costs. Installing PV panels, building insulation or heat pumps can be expensive and not affordable for many. However, it is possible to reach significant reductions in GHG emissions without major initial costs.
For instance, a key factor in building decarbonization is carbon-free energy. Building owners can purchase carbon-free electricity from a local supplier with a minimal investment. This action could lead to a significant reduction in GHG emissions, sometimes saving up to 50%!
Another critical aspect to consider in building decarbonization is energy efficiency. Incorrect thermostat settings, often caused by poor maintenance or faulty installation, may result in wasted energy. Setting the thermostat to achieve both comfort and energy efficiency or installing programmable thermostats that automatically regulate temperatures based on building use can lower energy demand. Air leaks can be another significant cause of energy waste. Simply sealing cracks can help to conserve energy and, at the same time, improve indoor comfort. Checking that lamps and luminaires mount LED bulbs is another not-so-expensive way to achieve energy savings.
Finally, people’s behavior can highly affect building GHG emissions. Simple awareness (or common sense), such as turning off lights when exiting a room, shutting down HVAC when parts of the building are unoccupied, and keeping windows closed when the HVAC operates, can impact GHG emissions considerably. For instance, a documented case showed that tenants’ awareness helped to save as much as 20% of GHG emissions.
Building decarbonization is not just a responsibility for a few. Many low-hanging fruits are within reach for any building owner who wants to reduce global GHG emissions. So much is possible—if only we could believe that!
