I happen to like this question a lot and I was reading some of the answers and I wasn't expecting to read what I did - thought it was pretty damn hilarious!

As for global warming?  I've slightly on the side with the rest of the gang that says there is no global warming.  

I believe there's a thing called global shift, but actual warming, nope, sorry, it doesn't float with me.  The world isn't getting hotter; how can scientists say the earth has gotten warmer; I don't believe the technical expertise of meteorology existed a 1000 years ago, so no one from that time can defend, or offend, global warming.

global warming is caused by the hole in the ozone layer which is getting bigger and bigger. If you don't believe it then please go to a country in the southern hemisphare and you will soon see just what global warming is doing.

It's NOT, for starters.
 Global warming is being caused by too much energy from infrared radiation being trapped within the earth's atmosphere by too much carbon dioxide.
The earth's core is slowly cooling off as its supply of radiactive elements is slowly depleted over time.
Please take a nice, full array of in-depth science classes.  Then, after that, it would be a good time to start coming up with theories of your own.

Well, it isn't. How could the core be heating up? Its only running on leftover thermal energy from its formation, partially aided by the enormous pressure down on it. The heat would have to come from somewhere; it can't just randomly appear from nowhere.

There is no global warming, there is no evolution, the sun goes round the earth, and the earth being flat, there is no "core."

And what if it was caused by farting, could we no longer eat beans?

That is unlikely.  More likely would be more of the core reaching the surface, but I'm not aware there are enough new volcanoes to account for that.  There are other more likely scenarios (besides CO2) for global warming than that.

The Earth's core can't heat up without some source of heat being applied to it.  It doesn't generate heat like a furnace, it just has its heat left over from when the Earth formed.

However, someone told me that if the Earth's crust couldn't radiate heat into space, the heat from the mantle would melt the surface.  So, we're standing on a crust of rock that happens to be "frozen" only because of the coldness of space.

Well, golly! If oprah said so then it must be true!

We would know if this were the case because the temperature gradient of the earth's crust is measured on a frequent basis. Oil companies and other drilling operations routinely measure bottom hole temperatures of wells that are several miles deep. This information is useful and necessary for both oil exploration and the operation of oil wells. It is also used by geothermal drillers who study where the best locations will be for utilizing geothermal power.

Here is a map of the geothermal gradient for North America:
http://www.smu.edu/geothermal/2004NAMap/2004NAmap.htm

Yes, if it were the case that the earth's core was heating up, then we would notice changes in climate, and many cooler weather plants would die after a few decades or centuries of warming because of warmer soil. Snow would melt more quickly, worldwide. Volcanic activity would probably increase as well. However, this is a very unlikely and probably impossible scenario, because the earth's core is heated by radioactive decay that is a very predictable and regular process. Not only is radioactive decay very gradual, it is also a process that slowly declines as more and more of the radioactive material decays to stable isotopes. Eventually the earth's core will stop heating itself and freeze. But you are correct in realizing that some of the heat on this planet comes from the planet itself.

What is incorrect here is the statement that earth's core has heat leftover from formation- this is not the source of the heat in the earth's core. It is from radioactive decay, which is much the same as nuclear energy.

It would take many many years for that to happen/ we will not be around!

I like your question.
You are thinking out of the box. Your mind is considering all possibilities and coming up wioth your own theories. I wish more and more people were like you - inquisative - and not afraid to go out on a limb and pose the question.
Good for you!
Now for the science...
The earth's core would only begin to heat up if there were some kind of chemical shift - some kind of new combustion that caused the heat. With the heat from the earth escaping through the atmosphere int ospace, and the surface of the earth absorbing the heat fomr the sun, our planet stays at a fairly balanced temperature range. For the most part, the earth's temperature is not governed by heat in the core, but by radiation from the sun - or lack thereof.
If the core began to heat up, pressure would begin to build. And if pressure began to build, earthquakes and volcanoes would be a constant. The earth's crust would thin out because of the heat and fractures would be more prone to erupt with new lava flows. It would lok like one of Saturns moons - or the planet that the Dark Sith Lord came from. :-)
So, the core is so well insulated that the surface of the earth could completely freeze over, and it's temperature wouldn't change. Conversely, the earth could become one large desert, and the same would be true.
No, it can't be the core, because the earth's crust is too deep for the thermal energy to penetrate.

Now about Global Warming...
It's time to stop ebating and start to combat what is occuring. Switzerland is wrapping it's glaciers in white tarps. Come on, people... call it what you will, but hundred year old glaciers are disappearing in decades.
Personally, I think it's a regular cycle that we cannot recognize because we haven't been around long enough. But isn't less greenhouse gas emissions a good thing? Isn;t less oil consumption a good thing? Isn;t less chemicals released in the environment a good thing?
Seriously, lets take som steps in ALL directions and try to preserve our environment. Arguing about it means that less is actually done.

Thanks for you question!

If the Earth's core were heating up enough to affect the environment, it would also have to be expanding--pretty sure even Bush would notice all those cracks that it would cause in the Earth's crust.

IF the earth's core was heating up, then yes, someday the ground would be too hot to walk on. We'd be dead long before that happened though because plant life would die first and we'd starve after we cannibalized each other to extinction.

OR...We'd build our cities on stilts and live up in the air and construct huge vent shafts to space that would cool the air and circulate it down through our floating cities. We'd all pee over the edge and try to cool the ground off until it gradually cooled the surface enough to let us walk on it again.