There are a lot more than 25 coal plants in the world, and we must stop using them very very soon. Here's an EPA-citing source claiming 1 Gt coal -> 1.8 Gt CO2e, and 3.5 Gt used by China in 2011, the latter amounting to ~6.5 Gt CO2e, and ~20% of world emissions that year. [1] If Chinese coal use is now about the same, and if we have 650 Gt left before some particular nasty tipping point is reached, then China's coal is currently using that budget at a rate of 1% a year. There's a lot of uncertainty in the rate measurements, and significant uncertainty in the tipping points, but there is no uncertainty that world will be like nothing humanity has ever seen at 500ppm CO2, and we have no reason to think that, say, Pakistan, India and Bangladesh can adjust smoothly to regular high temperatures of 54° with sporadic heat waves at 57°, or that America and the US can smoothly adjust to most of the farmland that currently feeds them becoming unusable and most of the fisheries collapsing.
Finally, note that we're not going to get to near carbon-neutrality in 30 years by dropping radically next year, continuing at a flat 1/30th of our budget for 30 years, and then dropping to 0. Any plausible route will accelerate GHG reductions something like linearly.
[1] http://www.sourcewatch.org/index.php/Existing_U.S._Coal_Plan...