Two things: firstly, just because something isn't 100% green or clean, doesn't mean it doesn't provide a useful reduction. Secondly, this is a "bootstrap" problem. Build enough wind, solar, hydro and nuclear and you suddenly have enough electricity generating capacity both power more processing plants using electricity as well as to make hydrogen fuel using electrolysis to provide fuel for "mobile" power. (i.e.: transport and remote locations.) Then things become really interesting!
"Years are in the thousand" indeed. A single pixel in this graph spans 600 years, so nowhere near the resolution required to tell what has been happening since the industrial revolution. Here's a a graph someone made earlier:
From the Vostok chart you can see that, periodically, temperatures and carbon rise at the same level. This has happened for may reasons; there have been periods of great volcanic activity sending CO2 into the atmosphere, heating up the planet. There have been periods of increased solar activity that increased temperatures, which, combined with the much higher oxygen concentration at the time, caused raging bush fires that emitted large amounts of CO2, causing a chain reaction of even higher temperatures causing more fires.
Looking that the 1000-year graph above, it is painfully clear that for close to a 1000 years, the temperature was stable, but when the industrial revolution started, CO2 went up dramatically, and the temperature soon followed. We don't have great many solar-activity fuelled bush fires at the moment, nor a plethora of volcanic eruptions. This is our doing. That nature did it on its own 100,000 years ago is no consolation when seas rise and flood low lying land. Or melting north pole ice disrupts the north atlantic conveyor and starts another ice age in Europe. All because of our fossil fuel burning habits.
If we can stop emitting su much CO2 and put off the next naturally-caused ice age another 10,000 years, that's just fine by be, and my grand kids.