Let's take these reference you cite one at a time:
* The first article (abcnews.go.com) is by far the most ridiculous. It is really a total embarrassment for the people quoted in it, especially Mr. Caplinger (who fortunately turns out not to be a scientist, because if he were, I would be embarrassed myself)
Here is what they found:
The evidence came by monitoring icy pits, ridges and mounds at Mars' south pole at the start and end of a Martian year. By comparing images in 1998 and 2001, the team noticed a dramatic widening of pits in the frozen mass and a shrinking of the mounds and ridges.
From this evidence, Mr. Caplinger jumps to this:
Michael Caplinger of San Diego's Malin Space Science Systems points out that if the warming were to continue at the same rate (that's a big "if"), Mars could become a nearly inhabitable place for people within 5,000 years or so.
"Rather than wearing a spacesuit, you could get away with wearing just an oxygen mask and a thick parka," said Caplinger, who co-authored a study about the observations in this week's issue of Science. "It would be like standing on top of Everest."
This is a totally ludicrous leap of logic that can hardly be explained away by the 'big if' comment. It is like taking the following data---Chicago, July 1 2000: High of 92 degrees. Chicago, July 1 2001: High of 88 degrees---and then concluding: At this rate of cooling, the entire Earth will be experiencing a new ice age within a couple decades.
:crazy:
* The next article (marstoday) appears much more respectable, but also has absolutely nothing to do with long-term climate change on Mars. Here is what was found:
... within the last month, the global atmospheric temperature of Mars has increased by approximately 50 degrees Fahrenheit, according to data being received by the Thermal Emission Spectrometer (TES) on NASA’s Mars Global Surveyor spacecraft. The cause of this sudden shift is a giant dust storm that has snowballed and now has enveloped almost the entire planet, absorbing a lot of the Sun’s energy in the upper atmosphere.
This is a short-term (essentially seasonal) change brought about by a weather phenomenon that does not exist on Earth (global dust storms). So its relevance to long-term global warming is non-existent.
* The 3rd and 4th articles are both referring to the same study; this time about Pluto. Again, the changes being observed on Pluto are totally seasonal. Pluto takes over 200 years to orbit the Sun, and, unlike Earth, moves significant closer and farther away from it during its orbit. The changes seen took place over a mere 14 years and can only be described as seasonal: like the changes on Earth from Northern Hemisphere winter to Northern Hemisphere spring. There is no evidence here of any long-term climate changes on Pluto. Measuring such changes would require observations of Pluto's weather for many thousands of years in order to account for the seasonal changes that take 200+ years to cycle though.
So that takes care of all your references about supposed 'global warming' on Mars and Pluto.
--Peter