It's irrelevant when compared to the amount of energy from the sun. World energy consumption is roughly 5.4 * 10^20 Joules per year. This is 86% of the total energy from the sun that hits the Earth in an hour.
It's like worrying over putting a single drop of poison into the ocean.
Man, every once in a while you remember the scale of energy when you're talking about the sun. Good lord.
It outputs our yearly energy usage in about a microsecond, and converts 4 million tons of mass to energy per second.
However, per unit volume, it's putting out energy about the same as a compost heap.
Adding more heat doesn't change the equation, it's how much we retain.
According to Wikipedia, the global energy production for 2012 was about 5.616e+20 joules, or 156 petawatt-hours. The Earth has about 1.386e+21 liters of water on it, and I will assume that that water represents the bulk of the relevant thermal mass, when considering weather patterns and sea level.
Now, let's estimate the heating caused by that energy. According to www.bickfordscience.com/03-05_State_Changes/PDF/Specific_Heat.pdf, 4,184 Joules of energy applied to 1 KG of water will raise its temperature by 1 degree Celsius, and this scales linearly with mass. Assuming that Earth-water averages out a density of 1 KG per liter, our 5.616e+20 joules, applied over a year to our 1.386e+21 liter water mass, would heat that water by 1.036e-38 degrees Celcius.
It has been a while since I've done a dimensional analysis, and the scale here are so extreme that I can't tell if my result is sensible. However, if my assumptions are reasonable and my math is correct, and the processes that I have chosen to ignore are insignificant (i.e. radiation into space over one year), then all of the heat that we release in the generation of the global energy supply, has a negligible impact on the temperature of the planet.
https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...
Relatedly, though, won't this cool the core?