Here’s Earth Hour: A Dissent by Ross McKitrick, an economics professor in Ontario who abhors the idea. It’s a single page PDF, in which he puts his ideas very succinctly.
This snippet will give you the flavor of it:
People who see virtue in doing without electricity should shut off their fridge, stove, microwave, computer, water heater, lights, TV and all other appliances for a month, not an hour. And pop down to the cardiac unit at the hospital and shut the power off there too.
No Truce With Kings 