'Heat' is such an over-rated but poorly understood concept.
In the final analysis, there is no such thing as 'heat' and 'temperature'. Look up the definitions, and they form a tautology - 'heat' is what is measured by 'temperature', and 'temperature' is a measure of 'heat'. If you remove 'heat', you lower the 'temperature'. But to remove 'heat', you do so by lowering the 'temperature'. Really, there is no such thing as 'heat' and 'temperature' outside of the human experience.
Humans THINK there is such a concept, only because we are warm-blooded, and we have evolved particular biological sensors that send signals to the brain which are interpreted as 'hot' and 'cold'. These in turn have lead us to believe there really is such a thing as 'temperature', that can 'measure' this thing called 'heat', into degrees of 'hotness' or 'coldness'. In truth, what 'temperature sensors' are detecting is 'high energy, high vibration, high expansion, high radiation' as 'hot' and 'low energy, low vibration, low expansion, low radiation' as 'cold'. When we measure 'temperature', we are actually measuring artifacts of the energy state - expansion, vibration leading to state change, emitted energy levels, and so forth. But 'hot' and 'cold' are purely constructs of our minds.
So what you are after, is how to move energy from one place to another, or to convert energy from one form into another. The cause of 'global warming', once we strip it of the psychological concept 'temperature', is that the earth is retaining more solar energy than it is radiating back into space. It is the energy levels of earth that are going up, not this particular physiological artifact that we refer to as 'temperature', and it is this increasing energy levels and the physical changes resulting from high energy levels that is causing the problems, not that things are getting 'hotter'.
So unless you have some mechanism of removing this excess energy from the earth, everything you do will amount to 'robbing Peter to pay Paul'. You might deplete the available energy in one place (lowering the vibrations, movement, radiated energy, and so forth), but only at the expense of building it up in another place. Eventually, that energy will flow back, equalizing the energy distribution.
In fact, that is exactly what is happening today. The excess energy produced by the sun, and absorbed by the earth, has been stored over billions of years in what we are now using as sources of energy - fossil fuels. All of the energy in oil and gas originally came from the excess energy of the sun, was biologically chemically converted into long-chain carbon molecules by biological processes, and stored in the earth. We are now releasing that energy back into the earth's atmosphere, and that increased energy is being perceived by us as 'getting hotter'. No, it is not 'getting hotter', the air molecules are just vibrating more. Winds and storms have more energy. Electrons and electrical charge is building up in the atmosphere, and being released in lightning discharges. Rocks and such are radiating more of this energy through the EM spectrum. Water, rocks, and the earth's crust are expanding.
So, your solution is to mimic biological evolution.
Use huge masses of plants and biology to take all of this excess radiated EM energy and convert it to long-chain carbon-based molecules. Store it as oil. The humans must vacate the earth's surface completely. Live underground, that is a start. No roads, buildings, parking lots. Let vegetation, of any form, completely over-grow every bit of earth's surface, then continuously cut the vegetation down and store it in huge 'compost bins'. The only products and manufacturing processes we can use, are the ones directly related to plants, not resources from the earth that have to be processed through the expenditure of energy. Basically, everything must be made from wood, hemp, and plant fiber, not concrete, steel, and refined minerals. As the vegetation continues to regrow, it will continue to do what vegetation has always done on the earth - convert energy to long-chain carbon-based molecules, and store it.
In this way, your underground apartments and living units will be 'cooled' (energy levels reduced) by the vegetation covering them, and you will let the plants do the manufacturing, not the materials fabrication industries.
But minimal electronic communications. That requires processed copper, aluminum, or other such metals. Can plants manufacture fiber optic cables?
Fun fact - the earth just may be the only place in the entire universe that has oil and gas, if in fact earth is the only place that has life.