One need not look further than Google, the search engine giant, to understand the ratifications cloud hosting has on the environment. Financial considerations apart, by using ordinary machines for building their cloud infrastructure, they are also saving the environment from unnecessary pollution. Only 15-20% of the e-waste generated by dumped computers can be recycled. The remainder, consisting mostly of electronic components, release toxic chemicals that leech into the land, or into the atmosphere, causing immense dangers to the environment.
This problem can be easily resolved by reusing those computers in a proper cloud-hosting environment. One can easily create powerful computing resources through old and used servers. We can reduce failure risks, associated with employing old machines, by spreading the computing over a number of machines. Many EU states do not permit plastic from e-wastes to be recycled because of the harmful dioxins and brominated furans released into the atmosphere during the recycling process. There are two solutions to this problem… store those plastic wastes in such a manner so that they cannot pollute the atmosphere.
The other option is to re-use those machines in a cloud-computing environment instead of discarding them. Webhosts generally pull off servers off the shelf after their customers have left them. After a period, these unused servers find their way into the dumping ground, paving way for further pollution in the future. The cloud-computing environment permits those webhosts to reuse those servers. Various factors like virtualization have helped conserve power in the cloud-computing environment. This decrease in the use of energy indirectly reduces the carbon footprint on the environment.
On a smaller level, one can network the unused computer, lying around in their home, with millions of similar computers throughout the world. Just try to think of the positive difference this can make to the environment.