We are constantly finding new and useful ways of using our natural resources in beneficial ways. The idea of cooling buildings from the bottom of a lake is awesome. More research is needed to find more ways of turning nature into valuable resources to carry on our daily lives with.
Most of the coolants used in air conditioning systems are poisonous, like freon, so using ice-cold water is definitely an improvement. This is eco-friendly design, and we need more of it. It shouldn't be used by so many buildings that the ecosystem of the lake is threatened though. Other neat ways to use nature to cool buildings include putting gardens on the roofs -- which uses the sunlight without generating heat.
The water at the bottom of the lake does regenerate itself quickly and using something that is natural like the lake as opposed to something like Freon or other chemical coolants is not only better for the environment but also for those that are coming in contact with it in the long run.
Since the dawn of the industrial revolution, our natural resources have been misused. The damage to our environment attests to this. Far too many of the decisions made about how to use resources and which resources to use or not use are controlled by the companies which directly profit from these decisions. We are quickly depleting the reserves of such things as coal, petroleum and natural gas. Far to often we see the devastating consequences of seeking these resources in an unsafe manner and areas where the environment is severely damaged. Yet such options as wind and solar power, virtually self-sustaining, are ignored or actively lobbied against. Government should base decisions upon a more enlightened viewpoint rather than bending to the wills of big petroleum and gas conglomerates. These companies should be barred from influencing the decisions made about our resources. The conflict of interest is obvious. These companies are interested in profits at any cost to the environment. Governments should base funding and licensing decisions upon the net worth to the people and the environment which the people expect them to protect.