Thinking about global energy demand

I have been thinking about the infinite energy demands we place, and continue to place. There are several ways to think about this.

1. Hypothetically, let's compare a car and a human. A car can take us long distances fast, but is it necessarily cheaper than feeding the human(s) to walk/cycle there? How about the energy efficiency between the two?
   
   (I tried doing some back-of-envelope calculations but ran into tricky conversions to properly compare biological and technological energy requirements - between kcal/day and mpg. However, at least for the car example, it seemed like there is a sweet spot for energy efficiency of a car compared to a human: a car is not efficient at all for a single person but becomes increasingly efficient with more people, "breaking even" with the 3rd person, or past a certain distance. Still, would love to do the calculations again - help appreciated!)
   

2. In pessimistic economic scenarios, renewable energy sources are written off because their capacity will never reach the energy demands of today and tomorrow. In optimistic reports, renewables will eventually exceed current energy demand and keep up with future demand. In neither scenario is there even a question of reducing energy demand, only growth.
   
   This is not to mention Jevons paradox which observes that technological efficiency does not result in net decline of energy demand, due to increasing demand for the new product.
   
   So for the near future, expect growing energy demand.
   

3. Each year, we introduce more gadgets and devices, which don't replace but aggregate. The world gets just that much more connected to the grid and the internet. The economy employs more and more computation in its sales cycles. Soon, entire currency systems will exist completely as computational economies. We literally dream of a world with more and more connected devices - we call it ubiquitous computing - but don't ask why! We are building now artificial intelligence algorithms that are most beneficial when they are continuously active, continuously processing and sorting data.
   
   Each new device and computation only adds to the energy demand.
   

4. Meanwhile the population keeps rising, poverty keeps falling, demand is continuously stoked. Net effect, growing energy demand.

Now, none of this is to stoke fears of running out of energy or resources. Hypothetically, becoming a spacefaring Kardashev Type I civilisation (or greater) would solve both these things. 

I sometimes wonder why though. Why are we driven to this path of history exactly? Where is this seeming great acceleration going? Should we blindly let it drive us, or is it time for to take the wheel for ourselves? Is there a preferred destination we can all choose together?

On a more practical front, I have a genuine non-rhetorical question. Due to the inefficiency of energy capture and transfer systems, there is always loss via heat. Greenhouse gas warming has estimated impact 100 times greater than waste heat warming (quick-scan supporting article in comments). But a hundredth unit of astronomical amount of energy that is disrupting the life-supporting homeostasis of an entire freaking planet in a matter of decades (!) seems to me like a significantly high figure!

So I ask, in the meantime how can we release this heat buildup? (Is this really so crazy? We routinely design chemical plants to vent waste heat.) Solving this at a planetary level sounds like a responsible prerequisite for the future we seem to be heading to right now.