It’s true- we did save a lot of energy with Earth Hour – ESKOM here published figures, but saving energy is not the primary concern, reducing air pollution is.
You are measuring what we didn’t use from power stations and ignoring what we instead dumped in the air from a few billion candles and lamps.

We need to get away from non-renewable energy because we’re running out, but that has nothing to do with global warming. We ALSO need to cut down on air pollution because we are going to kill ourselves if we don’t.
There is a link between these two separate causes, and it is this: Since we need to find new energy sources anyway, we should be smart and choose cleaner ones so we can get hit two birds with one stone.

And yet… go see who marched in Durban to prevent the building of another Nuclear power station ? The SAME people who led the earth-hour marches !
Right now, Nuclear energy is the cleanest, most viable energy reserve we have. It’s not renewable, but it’s a lot more readily available than fossil fuels, it doesn’t produce any air pollution and the water-heat pollution problem from older reactors can be prevented.
Modern breeder-reactors don’t even produce much nuclear waste, and what it does produce at the end of the cycle wears out in a hundred years, not thousands like older ones (and would be completely useless for weapons manufacture).

Nuclear is our only viable way of supplying our energy needs for a long time – we’re a while away from wind and solar being able to do so, perhaps we will never be able to harness those effectively enough, but we can get rid of coal and oil generators.
Right now – electric cars would make basically no difference, everything we save on car-emissions we’d be spending back in generator emissions to power the extra load on the grid (basic laws of science – the energy need to do a certain amount of work is always the same – you can get it from somewhere else but you cannot reduce it) – so the only way to viably fight back against global warming is this: build nuclear power stations, as many as we need to shut down every coal and oil station in the world, THEN build electric cars – and use things like tax-rebates to encourage their adoption.

Now try selling THAT to the people who celebrated earth hour ?

Residents and businesses across the city showed their support for Earth Hour resulting in an impressive 10.2% drop in energy usage across the usually glittering CBD, according to Energy Australia.

This is double the anticipated energy saving and represents a reduction of 24.86 tonnes of carbon dioxide – the equivalent of taking 48,613 cars off the road for an hour.