LESSON 4 · Green Tech That's Actually Working
Buildings Are Climate Villains
The built environment is responsible for roughly 40% of global carbon emissions. That includes the energy to heat, cool, and power buildings, plus the emissions from manufacturing concrete, steel, and glass. A single conventional office tower can emit thousands of tonnes of CO2 every year.

The green building movement gained real momentum in the 1990s with certification systems like LEED and BREEAM. These frameworks gave architects measurable targets for energy efficiency, water conservation, and material sourcing — turning green building from an aspiration into accountable practice.