Global Warming and the Gulf Stream

I brought this up in a forum the other day, but never got an answer, so I'm making it more public for some insight. I'll readily admit I don't think global warming - as a manmade occurrence - exists. The earth has cooled and warmed in the not too distant past. Remember the Little Ice Age (1650-1850) and the medieval warming period (800-1300 AD).

Someone brought up that Global Warming would cause the Gulf Stream to slow down and not circulate warmer water to the north (England, Europe) causing their temperatures to drop. This has happened before; the Little Ice Age. During the Little Ice Age, the Gulf Stream weakened by 10% between the 16th and 19th centuries. So, you have unexplained warming causing the Gulf Stream to slow down - before man had SUVs and caused global warming. Plus, we have scientists saying "we need to get rid of the medieval warming period". Why?

If you show that the planet has cooled and warmed all by itself, you have essentially disproven man's involvement in Global Warming have you not? It has happened in the past (pre industrial revolution); the Earth has warmed and it has cooled down again. If we are in a warming period right now - which is highly debatable, then why be concerned? If your interest is the health of the planet, isn't this healthy? Letting nature take its course. If the planet gets too warm, it finds a way to cool itself off again. Takes time, but it has - and does - happen.

I'll expound more on Global Warming another time.