Climate Change and Buildings: Energy, Emissions, and Resilience

Buildings shape our daily lives, but they also shape our planet’s future. From the energy used to heat and cool our homes to the emissions released during construction, the building sector plays a central role in the climate crisis. Understanding how climate change affects buildings-and how buildings affect climate change-is essential for anyone concerned about a sustainable future.

Buildings: a major driver of global emissions
Trends in residential and commercial sectors
Urban heat islands and comfort challenges
The cooling demand spiral
Uneven impacts across communities
Coastal vulnerabilities: flooding and sea-level rise
Types of coastal building impacts
Infrastructure vulnerabilities
Building resilience: adaptation and mitigation strategies
Coastal adaptation approaches
The path forward

Buildings: a major driver of global emissions

The building sector is one of the largest contributors to global greenhouse gas emissions. According to the International Energy Agency, building operations account for approximately 30% of global final energy consumption and 26% of global energy-related emissions. When you include emissions from manufacturing construction materials like cement, steel, and aluminium, buildings are responsible for about 34% of global CO₂ emissions.

These figures break down into direct and indirect emissions. Direct emissions come from burning fossil fuels on-site for heating, cooking, and hot water-think gas boilers and furnaces. Indirect emissions result from electricity and heat generated off-site but consumed in buildings. The latter category is particularly significant, accounting for the majority of building-related emissions.

The IPCC’s Sixth Assessment Report notes that total GHG emissions from buildings reached 12 GtCO₂-equivalent in 2019, representing 21% of global emissions that year. Residential buildings contribute roughly half of this figure, with commercial and public buildings accounting for the rest.

Trends in residential and commercial sectors

Between 1990 and 2019, global CO₂ emissions from buildings increased by 50%. Indirect emissions from electricity use grew by 92% during this period, driven by increased electrification that still relies heavily on fossil fuels. While developed regions like Europe have seen declining emissions due to efficiency improvements and cleaner energy grids, developing regions-particularly Eastern Asia-have experienced dramatic increases as urbanisation accelerates.

Space heating remains the largest energy end-use in residential buildings globally, followed by water heating, cooking, and appliances. However, one-third of global GHG emissions now come from both construction and operation of buildings, highlighting the need to address the full lifecycle of our built environment.

Urban heat islands and comfort challenges

Cities face a unique climate challenge known as the urban heat island (UHI) effect. Urban areas experience significantly higher temperatures than surrounding rural regions because buildings, roads, and pavements absorb and re-emit heat more effectively than natural landscapes.

Research by the U.S. Environmental Protection Agency shows that urban heat islands can raise daytime temperatures by 1-7°F (0.5-4°C) and nighttime temperatures by 2-5°F (1-3°C) compared to outlying areas. Several factors contribute to this effect. Hard surfaces like rooftops and parking lots absorb solar radiation throughout the day and release it slowly at night. Tall buildings create urban canyons that block wind flow and trap heat. Additionally, vehicles, air conditioners, and industrial facilities all emit waste heat into the urban environment.

The cooling demand spiral

As urban temperatures rise, so does the demand for air conditioning. This creates a challenging feedback loop: more cooling increases electricity consumption, which drives up emissions and generates additional waste heat, further warming the urban environment.

Research published in the journal Buildings found that ignoring UHI effects can lead to significant underestimation of cooling energy demand. In areas with compact mid-rise and high-rise buildings, cooling demand can increase by more than 20% compared to suburban areas. The UHI effect is particularly pronounced at night, when urban materials slowly release accumulated heat, preventing buildings from cooling naturally.

The implications are significant: increased electricity demand for cooling ranges from 1-9% for each 2°F increase in temperature, with the highest increases in countries where most buildings already have air conditioning. This additional demand strains power grids, increases the risk of blackouts during peak periods, and elevates emissions from fossil fuel power plants.

Uneven impacts across communities

The burden of urban heat is not distributed equally. Lower-income neighbourhoods often have fewer trees and green spaces, more dark-coloured surfaces, and older buildings with inadequate insulation. Climate Central research indicates that approximately 10% of urban households in the United States lack access to air conditioning, and many more struggle to pay energy bills-making it difficult for vulnerable populations to protect themselves during extreme heat events.

Coastal vulnerabilities: flooding and sea-level rise

Coastal buildings face growing threats from sea-level rise and increased flooding. According to the EPA, more than 40% of Americans live near the coast, where property and infrastructure valued at over $1 trillion is at risk from rising seas. The pattern is similar globally, with coastal megacities from Miami to Mumbai facing unprecedented challenges.

Data from the United Nations Development Programme reveals that 14 million more people now live in coastal communities with a 1-in-20 annual chance of flooding compared to two decades ago-a direct result of sea-level rise. By the end of the century, under intermediate emissions scenarios, nearly 73 million additional people could face similar flood risks.

Types of coastal building impacts

The threats to coastal buildings are multifaceted. High-tide flooding-sometimes called nuisance flooding or sunny-day flooding-occurs when water levels exceed local thresholds during regular tidal cycles, not just during storms. This type of flooding clogs storm drains, inundates streets, and damages infrastructure not designed for repeated saltwater exposure.

More severe flooding from storms and hurricanes compounds these challenges. According to C40 Cities, cities on the U.S. east coast are witnessing sea-level rise two to three times faster than the global average, while some Chinese coastal cities experience rises of more than 22 cm per year due to local land subsidence. Major cities like Miami, Guangzhou, and New York have trillions of dollars in assets exposed to coastal flooding risk.

A recent study in npj Urban Sustainability assessed building exposure to sea-level rise across Africa, Southeast Asia, and South and Central America. The researchers found that approximately 3 million buildings are currently at risk from 0.5 metres of local sea-level rise, increasing to 45 million buildings at 5 metres of rise-a scenario that could unfold over multiple centuries without aggressive emissions reductions.

Infrastructure vulnerabilities

Beyond residential buildings, critical infrastructure faces significant risks. The Cybersecurity and Infrastructure Security Agency (CISA) notes that data centres in coastal cities, fibre-optic infrastructure, and undersea cable landing stations are all vulnerable to flooding. Saltwater intrusion into freshwater aquifers threatens water supplies, while flooding of roads and bridges can isolate communities during emergencies.

The U.S. Climate Resilience Toolkit documents that more than 13,000 historic buildings, forts, and archaeological sites in the Southeast United States alone are at risk of flooding and inundation. Many low-lying transportation links-bridges and causeways connecting barrier islands to the mainland-were built decades ago at elevations now insufficient for rising seas.

Building resilience: adaptation and mitigation strategies

Addressing climate impacts on buildings requires both mitigation-reducing emissions-and adaptation-preparing for changes already underway. On the mitigation side, buildings can achieve dramatic emissions reductions through improved energy efficiency, electrification of heating and cooling, and integration of renewable energy systems.

The World Resources Institute highlights that cities can reduce urban heat island effects by 2°C or more through infrastructure changes like increased vegetation, reflective building materials, and better urban planning. Cool roofs-painted white or with reflective coatings-can be up to 50°F (28°C) cooler than conventional dark roofs under the same summer conditions, reducing both indoor temperatures and air conditioning demand.

Coastal adaptation approaches

For coastal buildings, adaptation strategies range from protective infrastructure to managed retreat. Indiana University’s Environmental Resilience Institute outlines options including flood barriers such as levees and seawalls, floodproofing through elevated equipment and waterproof foundations, and relocation of critical infrastructure to higher ground. Coastal wetland restoration can provide natural protection, with healthy coral reefs reducing wave energy reaching shores by up to 85%.

Many jurisdictions are updating building codes and zoning regulations to account for future flood risk. New York City, for example, developed a comprehensive resilience strategy after Hurricane Sandy, incorporating projections from an independent panel of climate scientists into planning and building requirements. Such forward-looking approaches recognise that decisions made today about buildings will have consequences for decades to come.

The path forward

Achieving a sustainable building sector requires action across multiple fronts. Energy codes must become more stringent and universal-currently, about 2.4 billion square metres of floor space are added annually in countries without any building energy codes. Retrofitting existing buildings for improved efficiency must accelerate from the current 1% per year to 5-10% annually. And new construction must increasingly target net-zero operational emissions.

The stakes are high. Half of the buildings that will exist in 2050 have not yet been constructed, representing both a challenge and an opportunity. With thoughtful planning, innovative technologies, and appropriate policies, the building sector can transform from a major contributor to climate change into a key part of the solution.

What do you think? How might climate considerations influence where and how you would choose to live in the coming decades? What role should building codes and urban planning play in preparing communities for a changing climate?

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Table of Contents

Buildings: a major driver of global emissions 🔗

Trends in residential and commercial sectors 🔗

Urban heat islands and comfort challenges 🔗

The cooling demand spiral 🔗

Uneven impacts across communities 🔗

Coastal vulnerabilities: flooding and sea-level rise 🔗

Types of coastal building impacts 🔗

Infrastructure vulnerabilities 🔗

Building resilience: adaptation and mitigation strategies 🔗

Coastal adaptation approaches 🔗

The path forward 🔗