An inconvenient truth

[xoxoxoBruce]

The National Geographic web site has a ton of links to articles on Global Warming. Most are predicting dire consequences for the future, floods, droughts, the usual scenarios, and many are pointing their finger at those damn dirty humans. A couple caught my eye....

http://news.nationalgeographic.com/n...l_warming.html

Global warming is a hot topic that shows little sign of cooling down. Earth's climate is changing, but just how it's happening, and our own role in the process, is less certain.
• Over the last million years the Earth has fluctuated between colder and warmer periods. The shifts have occurred in roughly 100,000-year intervals thought to be regulated by sunlight. Earth's sunlight quota depends upon its orbit and celestial orientation.
But changes have also occurred more rapidly in the past—and scientists hope that these changes can tell us more about the current state of climate change. During the last ice age, approximately 70,000 to 11,500 years ago, ice covered much of North America and Europe—yet sudden, sometimes drastic, climate changes occurred during the period. Greenland ice cores indicate one spike in which the area's surface temperature increased by 15 degrees Fahrenheit (9 degrees Celsius) in just 10 years.
• Since the 1860s, increased industrialization and shrinking forests have helped raise the atmosphere's CO2 level by almost 100 parts per million—and Northern Hemisphere temperatures have followed suit. Increases in temperatures and greenhouse gasses have been even sharper since the 1950s.
Water vapor is the most important greenhouse gas. Carbon dioxide, methane and nitrous oxide also contain heat and help keep Earth's temperate climate balanced in the cold void of space. Human activities, burning fossil fuels and clearing forests, have greatly increased concentrations by producing these gases faster than plants and oceans can soak them up. The gases linger in the atmosphere for years, meaning that even a complete halt in emissions would not immediately stop the warming trend they promote.

This is why I object to people saying Global warming is man made. I don't deny we are contributing, maybe significantly, but how much and what can we do to make a significant improvement?

http://news.nationalgeographic.com/n...alwarming.html

John Harte, an ecosystem sciences professor at the University of California, Berkeley, is already seeing possible future outcomes of global warming.
For 15 years, he has artificially heated sections of a Rocky Mountain meadow by about 3.6°F (2°C) to study the projected effects of global warming.
Harte has documented dramatic changes in the meadow's plant community. Sagebrush, though at the local altitude limit of its natural range, is replacing alpine flowers.
More tellingly, soils in test plots have lost about 20 percent of their natural carbon. This effect, if widespread, could dramatically increase Earth's atmospheric CO2 levels far above even conventional worst-case models.
"Soils around the world hold about five times more carbon than the atmosphere in the form of organic matter," Harte noted.
If similar carbon loss was repeated on a global scale, it could double the amount of carbon in the atmosphere.
Now, [the test plot] is just one ecosystem, and you can't make global claims from one alpine meadow," Harte cautioned. "But bogs, prairie, and tundra ecosystem studies are beginning to show similar results."

That's a surprise, the soil is losing carbon? I wonder if that was because of the loss of plants that mulch well? If the plants encouraged by higher temperatures don't return carbon to the soil like the plants that grow in cooler climes?

http://news.nationalgeographic.com/n...7_warming.html

Even if humans stop burning oil and coal tomorrow—not likely—we've already spewed enough greenhouse gases into the atmosphere to cause temperatures to warm and sea levels to rise for at least another century.
That's the message from two studies appearing in tomorrow's issue of the journal Science.
Researchers used computer models of the global climate system to put numbers to the concept of thermal inertia—the idea that global climate changes are delayed because it water takes longer to heat up and cool off than air does. The oceans are the primary drivers of the global climate.
"Even if you stabilize the concentration of greenhouse gases, you are still committed to a certain amount of climate change no matter what you do because of the lag in the ocean," said Gerald Meehl, a climate scientist with the National Center for Atmospheric Research in Boulder, Colorado.

Of course they're making the assumption that what appears to be a comparatively small contribution from burning fossil fuels, has significant effect on the big picture. That would indicate the "balance of nature" is much more delicate than we suspected. More delicate also means less predictable. I've a feeling that humans have had a much larger effect on the changes in Global warming than the burning of fossil fuels. We've literally altered the earth and it's ecosystem in ways that can't be undone without eliminating billions of humans. Hopefully Bush won't do that.