Climate change and its effects are some if the biggest challenges of our time. The COP21 target for 2050 is to reduce today’s CO2 emissions by 80-90%. Currently, buildings account for about 40% of total emissions in cities. Many of them are due to the building’s energy inefficiency. In the EU roughly 75% or buildings are not energy efficient, but the goal of the New European Bauhaus initiative is to renovate 50% of them by 2050. This includes making them more energy efficient through better thermal insulation, solar panels, heating and cooling systems. Building renovation is subsidized in many countries as one of the biggest undertakings of the construction industry. It would significantly reduce the negative impact of their operations to the natural environment and make them healthier for living.
Net zero has been placed as a goal for most cities: to produce only as much CO2 as it can eliminate or absorb through its nature. By increasing green areas, we will increase absorption of CO2, but a key part of the equation is to to reduce the CO2 emissions to the minimum across all industries.
Energy Efficiency is crucial because of the scarcity of materials, increased geopolitical conflicts, and also because of the pollution it causes and its detrimental effects on the environment. We’re already seeing an energy crisis developing that is pushing us to reconsider our energy use and decrease it. The use of resources on all levels has to be rethought and reconfigured. We need to be mindful of how much energy we consume and where it comes from and if we can improve this process and our sources of energy. The lack of affordable energy is currently forcing us to become autonomous. In building cities, we need to think of passive and energy-positive buildings that produce energy and not just consume it. Buildings could all have integrated solar panels or wind turbines to produce the energy they need to consume and sell the rest to the public grid.
Cities should also encourage people to be active in energy production on a building and neighborhood level. Instead of depending on large centralized corporations that require a lot of money to maintain and a lot of resources, energy production can be decentralized across distributed networks where people can sell their excess energy to their neighborhood grid and power others around them. This kind of energy sharing can also be a basis for other communal processes and integration.
We have to alsominimize the energy consumption in buildings, which is mostly used for creating thermal comfort. We can use different passive heating and cooling techniques that have been used since the times before air conditioning. The roofs of buildings can be used for solar panels to produce electricity, which would also keep them cooler. Thermal collectors can be used to warm up the water for domestic use and heating. Evaporative cooling and cross ventilation are traditional techniques that cool buildings in hot climates. External shading for the windows and double ventilated facades can reduce the heat from the Sun when needed.
In construction, we need to use materials that are environmentally friendly and have a low CO2 footprint. Research shows that, of all materials used for construction, wood has the lowest carbon footprint. In contrast, concrete and steel are materials that take a lot of energy to produce, which is consequently damaging the environment. Design and building techniques also play a major role as they can increase the comfort and quality of the built environment while reducing the negative impact on it. For example, proper thermal insulation can reduce the energy consumption of buildings significantly.
Climate change is also increasing the frequency and intensity of natural disasters. Thus, cities have to be prepared for catastrophes such as hurricanes, earthquakes, wildfires, heatwaves, droughts, and massive storms by investing in their own resilience. Many cities are built in coastal areas and are at a huge risk to be severely affected and damaged by floods and hurricanes. We need to develop architecture and cities that are protected from the imbalances in the environment. Infrastructure should be built in a way that it can easily be repaired. While we can’t do much to stop natural disasters, we can prepare and mitigate their negative impact through proper planning, design, construction and management of cities and key infrastructure by making them more resilient.