In the late 1960’s, many people in North America turned their attention to environmental problems, and new steel-and-glass skyscrapers were widely criticized.Ecologists pointed out that a cluster of tall buildings in a city often overburdens public transportation and parking lot capacities.

　　60年代后期，许多北美人把注意力转向了环境问题，那些崭新的玻璃钢摩天大楼受到了广泛的批评。生态学家指出，城市中密集的高层建筑经常给公共交通与停车场的承载能力造成过重的负担。