Cities play a crucial role in the urgent battle against the climate crisis, driving significant environmental impact and holding the potential to lead the transition to net zero. To effectively address CO2 emissions, it’s essential to evaluate the embodied carbon of built assets throughout their entire life cycle. 

In this article, we would discuss how cities can achieve net zero by reducing buildings’ emissions. But first, let’s find out what is net zero?

What is Net Zero?

Net Zero, or “Net Zero Emissions”, is an environmental goal that aims to reduce human-caused greenhouse gas emissions (such as CO2, CH4, N2O) to a level that is balanced with the Earth’s ability to absorb or remove emissions, to the point where the total net emissions are reduced to zero. 

This requires reducing emissions from sources such as transportation, industrial production and power generation. Besides, it also requires increasing carbon sequestration through measures such as planting new forests, forest conservation, and CCS technologies.

The goal of achieving net zero emissions aims to mitigate the impact of climate change under the Paris Agreement, with the hope of keeping global temperature rise below 2°C and efforts to limit warming to below 1.5°C above pre-industrial levels. 

To achieve this, both governments, businesses, and individuals need to commit to reducing emissions and supporting solutions for carbon sequestration, creating a less carbon and more sustainable global economy.

Emission Status of Buildings and the Net Zero Target

Cities greatly impact the environment and are key to fighting the climate crisis. They produce 70% of global CO2 emissions, mainly from fossil fuels in industry, transportation, and infrastructure. Despite some improvements during COVID-19, the buildings and construction sector is falling behind on decarbonization goals and likely won’t reach net zero by 2050.

Reversing climate crisis effects on society, biodiversity, and the economy is critical. At COP28, global leaders stressed the need for joint climate action to keep warming below 1.5°C. The event launched the Building Breakthrough initiative, with 28 countries aiming for near-zero emissions and climate-resilient buildings by 2030.

Most decarbonization efforts have focused on reducing emissions from building use and maintenance. However, this only shows part of a building’s carbon footprint. Therefore, it’s crucial to also consider embodied carbon, which includes emissions from a building’s entire life cycle, such as manufacturing, maintenance, and decommissioning.

WLCA’s Role in Achieving Net Zero

The buildings and construction sector often measures operational emissions but neglects embodied carbon. Evaluating both types provides a complete picture of a building’s Whole Life Carbon Assessment (WLCA). A WLCA totals all carbon emissions from a building’s life cycle, including both operational and embodied emissions.

Measuring emissions from building materials, such as extraction, manufacturing, transportation, maintenance, and disposal, is complex and needs reliable guidelines.

Existing Policies and Best Practices

The G20 Global Smart Cities Alliance and the Net Zero Carbon Cities initiatives at the World Economic Forum, together with Infosys and C40 Cities, lead a multi-stakeholder taskforce. This taskforce collates and evaluates best practices from local governments worldwide on embodied carbon. And, it facilitates discussions to promote the adoption of proven best practices.

The taskforce released a model policy on Whole Life Carbon Assessment Mandates, an Adoption Playbook for city officials, and a Practitioner’s Guide. These resources help cities and stakeholders craft policies mandating whole life-cycle assessments for significant developments.

Moreover, the policy assists governments in monitoring and reducing emissions from their building and construction assets. The taskforce promotes the model policy and guides for adoption by cities globally.

Recently, the policy was developed by examining practical policies from cities like London, Toronto, and Vancouver, along with tools from other organizations. These cities are reducing emissions and advancing net zero goals by measuring carbon emissions throughout a building’s life cycle, from design to demolition.

For example, several existing policies guided the creation of the global model policy:

• Toronto: The first in North America to set embodied carbon caps on new city-owned buildings via the Toronto Green Standard V4. This policy is becoming stricter to curb embodied emissions.
• Amsterdam: The Circular Strategy 2020-2025 aims for a fully circular economy by 2050. It includes mapping material flows and reducing primary raw materials, requiring whole life carbon assessments to measure and register operational and embodied carbon.
• London: To become a net zero city, London passed the London Plan. It serves as a blueprint for sustainable growth, addressing whole life carbon analysis, energy hierarchies, strategies, and reductions to decrease the carbon footprint.

Impact of WLCA on Decarbonization, Challenges and Global Risks

Cities are key players in the urgent fight against the climate crisis. To fully address CO2 emissions, evaluating the embodied carbon of built assets throughout their life cycle is crucial. Whole Life Carbon Assessment (WLCA) identifies carbon emission sources and supports accurate long-term carbon impact reporting and planning.

In fact, operational carbon alone can’t address the climate crisis or accelerate the net zero transition. 

The WLCA model policy offers a foundational guide based on best practices to standardize WLCA methods. This policy aids governments in monitoring decarbonization progress and helps the private sector develop shareable data and tools for supply chain coordination and low-carbon project benchmarking.

Growing global risks affect people’s quality of life and biodiversity, such as extreme weather events. For example, wildfires cause significant impacts, from safety and health risks to housing and employment challenges. The 2020 California wildfire led to insured losses of $5 to $9 billion. In 2017, Sonoma County’s wildfire increased rent prices by 40%.

Obviously, reliable and accurate information is essential for world leaders to make informed strategic, investment, and policy decisions. Shifting to an embodied carbon approach captures emissions data from built assets more accurately and promotes best practices.

Conclusion

In short, understanding the carbon footprint of the built environment is crucial for reducing global emissions. Cities like London, Toronto, and Amsterdam lead the way with whole-life carbon assessment approaches. However, greater international collective action is needed to expand best practice policies. This collective effort will safeguard both people and the planet while promoting economic prosperity.

See more: Net Zero and Carbon Neutral: What is the Difference?