Mars Global Surveyor, which went into service around the Red Planet back in 1997, has outlasted its original mission spec, giving planetologists a chance to view longer-term changes on Mars. One discovery with some Earthly implications -- the Martian climate is changing. The carbon dioxide ice cap at the south pole has receded each of the last three years, indicating that the planet is gradually getting warmer; NASA researchers are still working on precisely what is triggering this climate shift.
This is an excellent example of why the space program (particularly automated probes) is an important tool for building the Bright Green future. Determining what natural forces are at work warming Mars can help pinpoint the levels to which the same natural forces could contribute to Earth's climate disruption. Human activity far outweighs the effect of solar variation, for example, but it's important to measure just how much of an effect the Sun does have, so as to better determine what level of change to human activity would be required to pull us back from the brink (more solar influence=more work we have to do to bring the human influence down).
I'm just wondering where you got your source that said "human activity far outweighs the effect of solar variation" or this your opinion? i have read five articles from five different sources and they all question if it is just maybe the sun is getting warmer. if you remember earth did have an ice age and wouldn't have melted if it didn't get warmer. i don't believe automibiles existed back then. just a friendly different point of view.
The idea that solar forcing actually plays a relatively minor part in climate variation is a pretty common conclusion in the climatological literature. I'd say your best bet for confirmation would be to hit the Real Climate website (http://www.realclimate.org) and search on "solar forcing." Current research shows that the effect of the sun on the climate is roughly the same as that of CFCs (a minor greenhouse gas), less than half that of methane, and about 1/5th that of CO2.
See, in particular, this recent article (and look closely at the charts).
The idea that current warming comes from fluctuations in the Sun is reassuring, common-sense, and pretty much entirely wrong.
Just a quick follow-up to the last bit of the comment. Remember that nobody's arguing that the Earth doesn't have a natural climate cycle. What has been pretty conclusively demonstrated is that the current warming is (a) off-cycle, (b) MUCH MUCH faster than the natural cycles, and (c) strongly correlated to increased greenhouse gases.
We've experienced a change over the last century that would normally take thousands of years in a natural climate shift.