Already Being Built

Mass timber construction is emerging as a major breakthrough. Cross-laminated timber (CLT) can replace concrete and steel in buildings up to 18 stories tall, and the wood actually stores carbon rather than emitting it. Norway's Mjostarnet tower stands 85 meters tall, built almost entirely from timber.

Green roofs and walls are transforming cities too. They insulate buildings, soak up stormwater, reduce the urban heat island effect, and support wildlife. Singapore now requires new developments to replace any greenery lost to construction — some buildings there have more plant coverage than the land they sit on.