Sorry to any comments that got caught in the spam and moderation queues. I decided to take a week off from the whole blogging scene (including reading other blogs) because it was starting to get in the way of stuff that needed to get done. I’ll try to get around to replying to all the comments soon.

Anyway, a week off and when I open Google Reader, one of the first blog posts in from MT, Denialists Convincing Selves of Biodiversity Increase. The original source is Lawrence Solomon from the Financial Post. Like all good journalists (including CNN, NPR, and FOX), there is no link or citation to the journal article upon it was based.
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Lately, I’ve been looking at the differences in the two satellite temperature records. I first blogged about how there is a divergence in the two time series (RSS and UAH) with power at 1 year. In the same post, I noted that there appears to be a step in the difference time series, but at the time I did not pursue it further. Yesterday, I finally got around to blogging about the apparent change point in the difference time series.

I think I’ve exhausted the options of looking at only the global monthly temperature anomaly time series. Instead, this post will be about spatial differences in the two records. I obtained gridded data from UAH and RSS.
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The roles of aerosols and clouds as radiative forcing is the least well known aspect of the climate change problem. According the the IPCC 2007 Summary for Policymakers, aerosols represent a radiative forcing of approximately -1.2 W/m2, combining the direct effect of aerosols and the cloud albedo effect (also known as the first indirect effect or the Twomey effect). The estimate error in this value is +/- 1.2 W/m2. Other radiative forcings, such as CO2, have a much higher level of scientific understanding. The result is that the total net anthropogenic forcing is estimated at 1.6 W/m2 +/- 0.9 W/m2. The large uncertainty in the net forcing is almost all the result of unknown, or not-well understood, effects from clouds and aerosols.

Kim and Ramanathan (2008) use multiple satellite observing systems, along with ground-based measurements to compare the radiative forcing from aerosols and clouds with model results.
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Fully understanding the effects of aerosols on stratocumulus clouds is important in the climate change discussion. Low-level clouds have a significant cooling effect on the planet. In the 1970s Twomey showed that, all things being equal, by adding pollution (aerosols) to these clouds, they have a higher optical depth and thus reflect more of the incoming sunlight. This cools the surface more than the original cloud. However, things aren’t that simple; they rarely are in science. There are other effects that must be taken into account when looking at the effects of aerosols.

The work done by Guillaume S. Mauger and Joel R. Norris in Stratocumulus Sensitivity to Aerosols and Dynamics [May be behind paywall] is such an example. They attempt to find the causation behind the correlation between aerosol optical depth and cloud cover. The do this by looking at the stability of the boundary layer.
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