Discussing carbon neutrality in architecture should not only be based on local materials and new technologies, since there are many aspects that impact the construction production chain. From design to construction, without losing sight of the context and economic system of our society, the construction industry is responsible for a considerable part of the energy consumed worldwide. In order to interfere in this reality, it is necessary to expand the fronts of action, questioning the place of construction in our society.
After water, concrete is the second most-consumed material on the planet and its production is substantially growing, expected to increase from 4.4 billion tons, reaching production up to 5.5 billion tons by 2050. Unfortunately, this comes at a huge environmental cost, accounting for almost eight percent of the global carbon emissions. With this estimated expected growth, stakeholders in the construction industry must work on integrating sustainable building materials and innovative processes.
The Zero Carbon policy is intended to create a kind of ecological balance to neutralize greenhouse gas emissions. Several studies report that the construction sector is one of the main responsible for the unbalance in which we find ourselves today, after all, it consumes natural resources on a gigantic scale and still builds buildings that do not collaborate with the maintenance of the environment. Therefore, searching for paths towards a carbon neutral architecture has become fundamental and one of them is learning from past masters, such as the Brazilian architect João Filgueiras Lima, known as Lelé.
Carbon footprints and CO2 emissions are large topics in our conversations about how we create a more sustainable future. Over time, different companies, organizations, and individuals have pledged to alter their lifestyles and habits to make changes that show that they are dedicated to combating climate change. Especially in the design industry, where buildings generate nearly 40% of annual CO2 emissions broken down between daily operations and construction/demolition, architects have long been feeling the pressure of exploring ways to prove that we are doing our part.
Climate change mitigation has become a priority issue, with the architectural industry accounting for 38% of global energy-related CO2 emissions. In December 2015, the Paris Agreement proposed to limit global warming to less than 2 ℃ above pre-industrial levels and strive for no more than 1.5 ℃. The architectural industry must achieve net zero carbon emissions by 2050 in order to meet the Paris Agreement's goal.
Nowadays everything is “painted” green. It's green packaging, green technologies, green materials, green cars and, of course, green architecture. A “green wave”, stimulated by the environmental and energy crisis we are facing, with emphasis on climate change and all the consequences linked to global warming. This calamitous situation is confirmed by the second part of the report entitled Climate Change 2022: Impacts, Adaptation and Vulnerability prepared by the Intergovernmental Panel on Climate Change (IPCC) and presented in recent weeks. It reveals that, although adaptation efforts are being observed in all sectors, the progress implemented so far is very low, as the actions taken are not enough.
A carbon neutral building is achieved when the amount of CO2 emissions is balanced by climate-positive initiatives so that the net carbon footprint over time is zero. Considering their unmatched ability to absorb CO2, planting trees is often viewed as the best carbon offsetting solution. But as cities become denser and the amount of available horizontal space for green areas drastically reduces, architects have been forced to explore other approaches. Therefore, to address these climatic challenges and connect people to nature, exterior green walls have become a rising trend in increasingly vertical cities. Even if there is research to claim that these can positively impact the environment, many question if they can actually contribute to a carbon neutral architecture. Although the answer may be quite complex, there seems to be a consensus: green walls can be effective, but only through good design.
Almost no one buys an automobile for its stated price with cash on hand, so those looking to buy a car look to what the cost will be each month to own their automobile. Homes are our deepest investment, and most homeowners are equally as proud of their home as they are of their car and are terrified of its cost. So it is not surprising that “Net Zero” homes use the same sales tactic, proving their value by promising no monthly energy bills.
It is crucial to consider the future environmental impact of everything we create. Climate change remains high on the global agenda, and every industry must take part in the goal of reaching Net Zero. One of the more challenging industries concerns construction, which plays a vital role in the process of decarbonization and is constantly encountered with challenges to become greener. Therefore, it demands innovative techniques and development of data to find new and sustainable processes. One solution is to introduce and design both cleaner and more efficient materials. Bricks are a good example, as they can be used in building constructions to ensure a circular process and minimize carbon emissions, being an extremely durable material that can be produced with more sustainable techniques.
According to the architect and researcher Patrícia Akinaga, ecological urbanism emerged at the end of the 20th century as a strategy to create a paradigm shift with regard to the design of cities. With this, urban projects should be designed from the potential and limitations of existing natural resources. Unlike other previous movements, in ecological urbanism architecture is not the structuring element of the city — the landscape itself is. In other words, green areas should not only exist to beautify spaces, but as true engineering artifacts with the potential to dampen, retain and treat rainwater, for example. With ecological urbanism, urban design becomes defined by the natural elements intrinsic to its fabric.
Earlier this month, a series of cities worldwide have revealed various initiatives that would help them better understand the effects of climate change and shape a more environmentally conscious environment. From several American cities creating digital twins to help curb carbon emissions to the city of Brighton mandating bee bricks to foster biodiversity and Central Park becoming a laboratory for studying climate change adaptation in urban parks, cities take on a multidisciplinary and multi-scalar approach to environmental issues.