I was taught that all forms of energy on earth come from...
1. Solar
2. Tidal
3. Radioactive
4. Chemical
5. Outerspace sources
So in theory we do not add to the total energy on earth by using cellphones, microwave ovens , ham radios etc... we just convert one form of energy to another...
So example..
I have a solar panel that charges a battery, the battery powers a ham radio, the radio make radio waves into atmosphere.
Supposedly... science would say that my solar panel is 22% efficient, and the other percent is reflected and/or made into heat.
Then my battery is maybe 89% efficent and rest is heat.
Lastly my radio is only 20 % efficient and rest is heat.
But no new energy was created or destroyed, just changed form.
But... if we change how earth itself accumulates, retains, transmits heat, yes we do have ability to change temp.
I know this much... if we were to paint the earth land masses with asphalt, it decreases the albedo of earth, which I believe means we reflect less light. Which means earth collects more light. When light hits such a surface, it gets turned into heat. Most of that heat radiates into space, except...
The atmosphere is like a sermi-mirror and reflects it back...
So...
Our cities building materials, deforestation, and loss of ice, all cause earth to suck in more light and make it generate more heat energy. And again CO2, methane, etc... cause atmosphere to not let heat out.
And in the terms of nuclear power, what we are doing is releasing the heat stored in those radioactive elements faster than nature would have done. And given earth has a certain ability to release heat at a certain rate, that use of nuclear power should in theory temporarially increase global temps.
The best thing I can think of is to use less, recycle more , have less children, build cities with things like grass roofs, more greenery, more trees, less concrete, less asphalt, ...
If we all lived like it was 1600...no problems.
P.s.
Snow reflects more heat than ice
Water sucks in heat like a sponge .
Loss of snow on glaciers causes exponential (feeds on it's self) runaway reaction in terms of melting...