http://www.sciencedaily.com/releases/2006/09/060914095559.htm

<quote>
Changes in the Sun's brightness over the past millennium have had only a small effect on Earth's climate, according to a review of existing results and new calculations performed by researchers in the United States, Switzerland, and Germany.

In this image from an active solar period in March 2001, colors are shifted to highlight the contrast between sunspots (black and dark red) and the faculae that surround them (bright yellow). During the peak of the 11-year solar cycle, the expansion of faculae outweighs the darkening from increased sunspot activity. The result is a net increase in solar brightness. (Image courtesy of NASA)

The review, led by Peter Foukal (Heliophysics, Inc.), appears in the September 14 issue of Nature. Among the coauthors is Tom Wigley of the National Center for Atmospheric Research. NCAR's primary sponsor is the National Science Foundation.

"Our results imply that, over the past century, climate change due to human influences must far outweigh the effects of changes in the Sun's brightness," says Wigley.
</quote>

Not that facts matter, but it does put the nit in nitwit.

The sun is causing global warming! We need to put a stop to it! Put it out, Put it out!

I think global warming is caused by deforestation, increased concrete surfaces (more cities), and thermal pollution.

I wonder if someone can come up with an asphalt surface that is photosynthetic ... ie, it's tough, durable yet produces energy when there's no car on top of it.

Grass under glass or something.

I'm with Steel on the deforestation.  South America continues to cut down the Rainforest for slash-and-burn farming at an amazing rate.

How does deforestation cause global warming?

Perhaps the US should invade Brazil and make them put the trees back.

I read an article a few years ago that was going on the theory that the Amazon tropical rain forest was a *byproduct* of human culture. That indigenous folks had used methods which ended up utilizing the rain and went into a vicious/virtuus cycle of promoting the rain forest.

Their culture wasn't fit for the ecological damage (ie, large trees everywhere) it had caused, and so it died out.

You burn the trees, CO2 goes into the air.  There are fewer trees left to suck the CO2 back down, so it stays up longer.  CO2 is a greenhouse gas.

> Perhaps the US should invade Brazil and make them put the trees back.

But...but, that would be nation building!

Nah, just treehouse building, something any 10 year old is capable of.

So "I think global warming is caused by deforestation, increased concrete surfaces (more cities), and thermal pollution." left out the C02 ? i guess that is key.

Yup.