The biggest challenge facing humankind is to reconcile the impact of humans with the ability of our planet Earth to provide resources and absorb waste. This "crisis" presents a potentially pivotal opportunity for architects, who have a crucial role to play in addressing this challenge. Sustainable cities are the building blocks of a peaceful and sustainable world.

Of the two zones which constitute Earth, land is extremely vulnerable to misuse, distortion, and depredations. Although seas/oceans the other constituent is not free from encroachment and defilement, it is comparatively in much better health. Hence green infrastructure has land-use at the core of discussion. It is presumed that there is crisis regarding land-use.

As a pioneer in sustainable development, Singapore has been approached by the World Bank to provide technical assistance on urban planning in neighbouring countries. Vicente Carbona analyses Singapore

Toronto is aiming for an impressive three to five percent reduction in greenhouse gas emissions through the implementation of one programme