As a reply to your "edit":
You don't know how to bloody read. Claiming renewables emit CO2 in their construction and maintenance is not saying that they don't decrease emissions in comparison to gas-oil-coal, only that they do produce emissions. Unless you want to state that for a fact renewables are leading to no emissions for their construction or maintenance, you can't possibly be denying that. And by the way nuclear involves CO2 emissions too in its construction, surprise surprise! But you build it once and run it for a very long time, and the emissions in relationship to the energy output for nuclear completely dwarf anything related to renewables. So stop trying to argue an empty point.
Now, there's no such thing as "dispatchable" without a carbon cost that is non-negligible: the things you build, if you move them you're using trucks that use energy. If you take the windmills down from off the coast where the wind is stronger, you're using boats that use energy. If you need to use tools and to build any kind of structure for things to be installed anywhere new, including extensions to power grids, you're using materials for which the construction requires yet again energy and materials. Oh and now because we don't know on what scenario we are, weather patterns have changed significantly enough over the course of a few decades so you need to start moving your infrastructure to the "right" place, which includes building the damn road there and potentially moving people away too. You can "dispatch" all you want by emitting a ton of unnecessary CO2, or you can go and develop the source that is most reliable, actually controllable, and that only needs those emissions to be made ONCE to become a source of energy.
Stop daydreaming about things that are only marginally doing something, and put your energy into addressing problems at the order of magnitude where you have the real impact. For energy production it's nuclear by a huge margin, and yes that's what the damn physics says. Then move on to the other actual problems that lead to CO2 emissions, and work on those too. Stop trying to fix a problem that already has a solution - especially if your fixes involve a whole lot more repetitive CO2 emissions along the way.