Neptune has been growing steadily warmer since 1980.  No doubt this is due to greenhouse gas emissions, deforestation, rapid urbanization, jet airplanes, and other human influences.

No, it's due to variations in the Sun's energy output.

As it says on the World Climate Report blog:

If for some reason you do not believe that the Sun is a significant player in determining the temperature of the Earth (after all, we are told repeatedly that humans are causing most of the observed warming on the Earth), then asked yourself if you believe that Neptune’s temperature is controlled by the Sun. How is it possible that the Earth’s temperature is so highly correlated with brightness variations from Neptune? The news from Neptune comes to us just weeks after an article was published showing that Mars has warmed recently as well.

As an additional bit of trivia on this subject, have you ever wondered why Greenland is named that when almost the entire land mass is covered with ice?

The answer is simple.  It used to be green.  In fact, the Vikings farmed there up until about the 14th century, when it got too cold to do so.  The fact that it's still too cold to do much farming there, might lead one to believe that it was warmer there when the Vikings were doing their farming (from about the 9th to the 14th century).  No doubt this warming was also due to greenhouse gas emissions, deforestation, rapid urbanization, jet airplanes, and other human influences.  The Vikings really loaded up on those frequent flyer miles and were jet-setting all over the known world.

I don't deny that climate change may be occurring.  Just show me some real evidence that:

1. It's a bad thing (some argue that it may in fact be a good thing and make more  of the world habitable).
2. It's mankind's fault (and not the Sun or just normal cycles in climate change).
3. There's something that we can do about it (latest studies suggest cutting our emissions may only reduce global warming by less than 5% over the next 50+ years).
4. That we should.
5. That the costs of attempting to do something about it (economic and even environmental) are less than the costs of not.

Now, I'm reasonable.  I think we should do what we can to keep this planet a beautiful place.  I don't like walking out of my house in the morning and seeing another day of smog.  But we can work on issues like that without adding in unfounded mass hysteria related to some quasi-religious global warming cult.