Who cares if the Miyan calendar ends then? Ours is different, so the Miyans can believe whatever they feel.
As for climate change, it is obvious that it is changing. People will believe that an ice age could happen over the next 100 years, but it doesn't, and then some other group of people will say that it will happen, once again, in the next 100 years. Every scientist, climatologist, meteorologist, etc. has their views on when the next ice age will happen. Next 100 years, or next 10,000 years, who knows? The movie, The Day After Tomorrow, is a great example of how it could happen. All of the events, maybe with the exception of the three large, hurricane-like storms would probably happen. Another good example of changing climates is Al Gore's presentation. It's obvious from those findings that something is happening. When ice is fading in places that it should be (i.e. Siberia, Greenland, Northern Canada, Antarctica, etc.), then something within our climate is happening. Now, you say that a few degrees isn't a "big ripple in the water," but add it up over the next 50 or so years, and then you will have your big ripple on a planet-sized scale. Take for example, on how climate in places around the US changes various ways. Here in Northern Indiana for example, over the past two years in January just after New Years, the temperature has hit 60 degrees (F) three times, when the temperatures should be in the 20's and 30's, and then we hit the end of the month, and our temperatures are just above 0 degrees (F), and at night, the temperatures have gotten as cold as -20 degrees, when it should be +20 degrees, and I am not talking about just one day, I am talking about a week or longer event. Both of these events happened here in the past two years, and at the same time. Now that should say something about climate change, including when patterns in temperature change drastically over short periods of time.