Still, if London's underwater and winter's banished, that's some consolation.
The ice age is coming, the sun is zooming in
Engines stop running and the wheat is growing thin
A nuclear error, but I have no fear
London is drowning-and I live by the river
OK, there's been global warming before. The questions are, is it happening now, and is it happening because of humans? A consensus seems to be forming around "yes" and "yes", in which case action to reduce the human causes is warranted, don't you think?
See RealClimate in general for more on this; it's "a commentary site on climate science by working climate scientists for the interested public and journalists." This post in particular, "Just what is this consensus anyway?", seemed a useful summary to me.
If human activity is responsible for global warming, then why is Mars also experiencing global warming? Is it the fumes emitted from Spirit and Opportunity?
The Mars evidence, if true, pretty much means that the "yes" and "yes" consensus is hooey.
I keep an open mind about this stuff -- I'd like to see more study of the evidence from Mars, more understanding of how solar activity (which isn't constant) affects the earth, and how other variables fit in, but anyone who says he understands this stuff well enough to offer predictions should play the lottery -- his odds of being right are far better there.
"anyone who says he understands this stuff well enough to offer predictions should play the lottery -- his odds of being right are far better there."
_Anyone_? And you know that how?
I don't see how Mars' warming trend needs to have much bearing on evaluating the human effect on this planet's climate. It's a different planet, with different atmosphere, probably different geology, no open ocean, etc. It may have a more variable year-to-year temperature history than Earth. Given that most of the "snow" on Mars is frozen CO2, I'd guess there's a bit of an acceleration built in to any warming trend. At any rate, neither the article you link to nor the one it links to speculate on how the Mars data affect the analysis of warming on this planet.
Perhaps solar activity is the main underlying reason, and in that case it will no doubt be part of the explanation for Earth warming as well. But I'd feel like I was sticking my head in the sand if I discounted a consensus of trained climatologists quite so easily as you do.
Meanwhile, I'd also guess that we have much less of a timeline with Martian temperatures to work with. I'm not sure we can afford to wait for a statistically satisfactory number of years of average annual temperature on Mars to work out what to do about warming on this planet.