Provincial environmental assessment processes typically do not look at cumulative effects. In fact, I'm not aware of any jurisdiction that requires assessment of cumulative effects amongst the various jurisdictions in Canada. In Ontario, for example, the environmental assessment process is really limited to public sector projects. It doesn't even include the assessment of private sector projects unless they were designated by the Minister of the Environment in Ontario.
When it comes to substitution by provincial processes for federal processes, certainly there will be no guarantees that the cumulative effects will be assessed at all. Further, the criteria in the new bill relating to substitution are extremely weak and, as Jamie Kneen has said, will result in a patchwork of environmental assessment regimes across the country.
One benefit of the Canadian Environmental Assessment Act over the past 10 years has been, basically, to serve to elevate everybody's game. The provincial governments have not been able to run away from environmental assessment because there was always a risk the federal government might come in and actually want to do an environmental assessment. So they couldn't run away and hide. I think the reason the provincial premiers are pretty happy is because, with the federal government off the scene, they can basically downsize their own environmental assessment regimes. I think that's a real risk in some jurisdictions.