And now Mars

I saw an article today that said that the temperature of Mars is rising - Mars, too, is having global warming.

A few weeks ago I saw a similar article about Saturn.

And 'everyone knows' that the Earth is experiancing global warming.

Right away, I remembered the old saw "once is accident, twice is coincidence, three times is conspiracy". If three planets in our solar system (which now, apparently, only has eight of them, grumble grumble) are all warming up, isn't it reasonable to look for a common cause? I tried to see if the other five (or six, depending) planets are also starting to take off their sweaters, but nothing readily showed up in a web search. If they are, too, isn't it a little unlikely that humans are causing it? Even if they aren't, surely even those people who ignore the 4 billion year history of non-man induced climate change on this planet should have a hard time saying that a change now must have been caused by the human race if changes are also happening on TWO other planets we AREN'T on?

Post hoc, ergo propter hoc is still one of the worst arguements around.