Archive for March, 2008

Natural variability, waah?

March 24, 2008

Next time someone blames a hot day, week, month, or even year on global warming, tell them, “It’s called weather.”

Click on this link:  http://data.giss.nasa.gov/gistemp/station_data/.  It’s a map of the world; click anywhere in the world, and chose from a list of nearby surface stations to see the temperature history.  Look though a bunch and notice the variety of temperature trends.

Now here’s a graph of NASA GISS’s global average temperature graph for comparison.  The point I’m trying to make is not all regions have seen the same warming trend as give by NASA’s graph, in fact, the graph is borderline statistically meaningless.  If I gave you a graph of shark attacks thoughout the world that showed 100 attacks in 2000, 20 attacks in 2001, 150 attacks in 2002, 80 attacks in 2003, 60 attacks in 2004, 220 attacks in 2005, etc, would you feel confident in drawing a mean number of shark attacks per year to estimate 2006’s number of shark attacks.  The answer is no, because the mean will be statistially meaningless due to te diversity of data points. 

So, my question is, is the NASA GISS data like the shark attack data, or is representative of most regional trends?  Turns out that it’s somewhere in between, which you can see from the graphs I provided.  It is important to note though, that while the”global warming” signal is indeed visible in the regional graphs, it does not dominate their trends.  Instead, local changes in climate alter the temperature record signifcantly.  For instance, the Svalbaard Luft station, located on an island north of Russia, has seen nearly a 10 degree celsius increase in temperature over the past 30 years!  AGW proponents would argue that it has been caused by greenhouse gases, and skeptics would argue that it has been caused by changes in oceanic circulation, but either way, it shows the dominance of local climate phenomenon on regional temperature.  Hartford, as another example, seems not to have warmed for 40 years.  So that’s my main point; while globally averaged temperatures are somewhat helpful, local climate, which can be changed by alterations in ocean currents, cloudiness, rainfall, the jet stream, solar UV radiation, cosmic ray bombardment, etc, dominates regional temperature trends.  Therefore, looking at “global warming” as described the GISS graph is not helpful.  Instead, policymakers should be more concerned with regional changes in climate, and instead of attempting to stop the causes of these changes, it would be wiser to consider them inevitable.

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Various Global Temperature Records

March 24, 2008

This slideshow relates the above post.

Cosmic Rays #2

March 15, 2008

Nir Shaviv has made a great new post defending the cosmic ray theory.  The theory is contentious even within the skeptic community, and Shaviv is a big proponent, authoring several papers on the issue.

Welcome!

March 15, 2008

Here’s the new site.  Enjoy.