Timothy Birdnow

One of the fundamental assumptions in the climate change hypothesis is that the release of carbon dioxide into the atmosphere stimulates a degree of warming which in turn leads to the release of carbon dioxide into the Earth's atmosphere as a result of microbes becoming more active and metabolizing more trapped carbon in the soil, thus further increasing atmosphereic carbon dioxide and leading to more warming.

This paper challenges that notion.

Researchers at North Carolina State University decided to study soil in warmer climates, and especially in areas which had been former agricultural regions. Most studies on soil outgassing have been conducted in the Arctic and assume the Arctic soil works the same way as does soil on the whole planet. The researcher's findings show it does not.

The scientists looked at new forest soil in what had been old cotton fields. Cotton tends to exhaust soil of nutrients, and the new forest is full of scrub which thrives in exhausted soil. What they found was that there was little carbon dioxide released from these soils because they lacked the proper nutrients to foster bacterial activity.

The bacteria need high carbon dioxide levels in the soil as well as other nutrients (like phosphorous). Warmth isn't all they need; they need FOOD.

So surface warming is not in itself a driver of outgassing of co2.

While this in no way destroys the concept of anthropogenic climate change it does suggest our understanding of the carbon cycle is woefully inadequate. It also suggests the climate sensitivity is less than what the IPCC estimates it to be. (Climate sensitivity is the term used to describe the roll of feedbacks in the climate; high sensitivity means a positive feedback where a minor effect like a modest rise in temperature or warming leads to a feedback loop greatly increasing that effect, while a low sensitivity means negative feedbacks which tamp it down. A great example of low sensitivity is on Mars, where a warming at the surface leads to an outgassing of carbon dioxide from the soil (because the soil holds frozen carbon dioxide - dry ice) which increases atmospheric pressure which leads to huge wind storms that blow up dust, blotting the sun, and cools the planet back down, to refreeze the atmosphere in the soil.) The IPCC has always assumed a rather high climate sensitivity, that the positive feedbacks all push planetary temperatures upward. Skeptics have all argued for much lower sensitivity (and use geological history to prove it.)

So this suggests a lower sensitivity than the IPCC believes. Warming alone won't cause outgassing; limitations in soil fertility reduces that.

Again, this isn't a smoking gun rebuttal of global warming alarmism, but it's just one more thread coming loose from the great tapestry the Gang Green has woven.

Posted by: Timothy Birdnow at 07:41 AM | No Comments | Add Comment
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