On the other hand, I strongly believe that moving along at the current "gradual" pace will cause a massive overshoot. In our system, price sets everything. If I can pay for petrol, I will drive. If I can pay for the electricity, I will turn the air-conditioner on. As long as energy prices stay mild, BAU will continue unabated. Even if one country moves away from fossils, it just means the rest "enjoy" them for cheaper. So the only thing that cause a massive shift away from fossil fuels is a massive global price rise.
Obviously our current "gradual" rate is not adequate for us to hit something like a 70% decrease in CO2 by 2050. But I don't think everything is getting factored into people's thinking.
Renewables are becoming cheap. Just plain cheap.
Utility solar should soon be about $1/watt in the US. We've got farms being built today for under $1.50/watt. Onshore wind is cheap and getting cheaper.
In 2013 the US consumed 1,585,998,000,000 kWh of electricity generated with coal.
A 1 kW solar panel array would cost $1,000 (assuming a 20% CF) would produce 1,752 kWh per year.
(1kW * 24 * 365 * .2 = 1,752 kWh)
It would take 905,250,000 1 kW arrays to replace the electricity produced by coal. The cost at $1/watt would be $905,250,000,000.
Spread out over 20 years this would be $45,262,500,000 per year. $45.3 billion per year.
It's hard to calculate what the US spends for coal each year because the price of Appalachian coal is between $55 and $60 per ton. Powder River coal is selling for about $12 per ton. I don't know the percentage of each used.
In 2013 the US consumed 858,400,000 tons of coal for electricity production.
At $12 that would be $10.3 billion.
At $55 that would be $47.2 billion.
The external cost of burning coal runs between $140 billion and $242 billion per year for health costs alone. Environmental and climate change costs are not included in that range.
$45.3 billion per year for 20 years would eliminate coal consumption. We'd save between $10.3 billion and $47.2 billion on coal purchases plus between $140 billion and $242 billion on health care for decades to come.
Taking the lowest numbers $10.3 billion + $140 billion, that's 3.3x the needed investment in solar farms on an annual basis.
Wind, with it's higher CF should be as cheap or cheaper than solar. It's going to be a race to see which can get below 3 cents per kWh first.
Almost all countries are concerned about climate change. Few will greatly increase their use of fossil fuels, even if the price is low. At $12/ton coal is not competitive. Neither is $2/gallon gasoline.
Electricity consumption will likely rise in many countries. It may fall a little in a few thanks to efficiency. It really doesn't matter if people want to use more electricity as long as it's from renewable sources.