Human Effects
This is more about what We can do, as a specie, to take control over it. Right now, we aren't taking Responsibility for our pollution, we're making excuses for it. (Warning, this is complicated, and full of Details)
Heat
Again, it's not just Greenhouse Gasses, but how they get there. Thermodynamically, you can't get energy from nowhere, only change energy from one form to another. That's the first rule. The second rule is you can't even break even, whenever you change one form of energy into another, what's left is changed to Heat.
That's why turning the Chemical energy into Mechanical energy in an internal combustion engine makes it hot. It's not just the explosions of fuel, and air in each piston, every quarter cycle (In a 4 stroke Otto cycle) but also friction, and even reciprocation (The piston stopping, and turning around 8 times per cycle) that causes losses, which are released as Heat.
This is where we get into Efficiency, and Inefficiency. Basically what's driving this macro-effect with micro-effects. It's less efficient to refine crude oil, ship it to gas stations, and put them in our cars so we can burn them. (It makes Money, and literally drives the Economy, though.) When it gets to the gas tank, it's a measure of the Complexity of the system, how many times energy is changed from one form to another.
In the fuel pump, mechanical energy is changed into hydraulic energy (And heat.) In the Radiator, electricity is changed into mechanical energy, which is changed into pressure to pump coolant through the engine, then back out to the radiator, where it can be blown away by the fan. In the Alternator, mechanical energy is changed into Electricity to charge the battery, which changes chemical (Lead Ions) into electricity, to run the radiator...
And the Air Conditioner, the Satnav, your phone plugged into the cigarette lighter, and make the windows go up, and down. (And heat.) Put together, the entire system makes the whole thing go forward, while there's a hydraulic pump to squeeze ceramic plates against a steel disk to absorb that energy, and make you stop. (Releasing all that mass, slowing from 10s of miles an hour, as heat.) This is just 1 car, but believe me when I tell you that ALL of our technology works this way, because Entropy is one of the things that underpins the Physics we base all of our technology on. Massive amounts of R&D go into cooling, everything from laptops to cars, and the inverse of the 1st Law of Thermodynamics is that Energy can't be Destroyed, either. That heat doesn't go away, it's invariably dissipated into the atmoshpere as Convection, or Infrared Radiation. (The band that greenhouse gasses absorb)
You can't make a 100% efficient engine. When your cell phone turns electricity to light, it produces waste heat. When your refrigerator cools off those steaks you picked up from the Piggly Wiggly, it produces more heat than it sucks out of the sealed container, and so does your air conditioner, to get rid of the waste heat your refrigerator releases into your home. This is a relatively minor effect, compared to the sun that hits the surface every day, but it's getting larger.
More people are being born, and getting things like refrigeration in "Undeveloped Countries." More people are being developed, and getting access to more technology, every day. We have rap stars buying up Photovoltaics to take to African villages, and I say this is a Good thing! Don't get me wrong, I'm not a luddite, and saying that the technology we take for granted is bad on the internet is too much irony for me to find funny.
However, at some point (Again, we're not there yet) it becomes Too Much of a Good Thing. Like Petroleum, that was good when we were still using Steam Engines, and Whale Oil to read Moby Dick by gaslight. However, we tend to do things like have a drink, start having a good time, and then keep drinking until we end up in hospital with Alcohol poisoning.
We don't have to stop, not yet, but we need to slow down, and think about things like Heat Pollution, before they are too much for us to handle. The first stage is Denial, and I'm not ready to accept the death of the human race.
Not yet.