|Abstract||The physical magnitude of the Canadian air, land and water environments together with their natural scavenging mechanisms can assimilate more pollution than is produced in energy conversion.
Nonetheless, concentrations of pollution at single sources and the proliferation of sources exceeds the capacity of the environment in some specific, but widely separated, areas. Thus, if our environments are to be given a reasonable opportunity to
assimilate pollution, there is no choice but to ensure that stack emissions are minimized and, having done that, to make full use of the dispersion capacity of air sheds. However, neither fuel highgrading, i.e. the use of premium fuels as an
expedient for the moment, nor pollution controls that waste energy are viable long-term solutions for protecting the environment. The effect of winter conditions on scavenging mechanisms is described, adding emphasis to the need for proper plume
dispersion. Otherwise, pollution may concentrate in snow only to run off in the spring to the water environment. The limited dispersion capacity of the sub-arctic and arctic air sheds, under winter conditions, is mentioned, but the obstacle to energy
conversion may not be too serious in large areas where bogs and wet lands are strongly acidic. However, lichens of the arctic tundra could be easily destroyed by sulphur dioxide emitted from heat processes so that the risk to the delicate arctic
ecosystem seems grave unless special precautions are taken to continue using non-polluting fuels and to avoid ground-level fumigation. Heat pollution and the possibility of large-scale nuclear power generation in the foreseeable future are also