Posts

Showing posts from January, 2014

The problem with "All of the above"

Image
President Obama in his State of the Union address praised his "all of the above" energy strategy.  What he left out is that "all of the above" is a recipe for disastrous climate change.

The 12-month running mean for Mauna Loa CO2 levels is currently at 396.18 ppmv.


With a climate sensitivity of 0.809ºC/W/m2 (3ºC per doubling CO2), that translates to warming of
ΔT = λΔF = λ*[5.35 W/m2 * ln(C/C0)]
ΔT = 0.809ºC/W/m2 * [5.35 W/m2 * ln(396.18 ppmv/280 ppmv)]
ΔT = 1.50ºC above pre-industrial levels with just the CO2 levels of today.  However, that climate sensitivity value is just the 100-year value.  At longer time spans (i.e. 1,000 years), sensitivity is actually closer 1.618ºC/W/m2.  That means that at today's CO2 levels, we're already committed to 3ºC of warming over the next millennium.  The key phrase?  "At today's CO2 levels."  And that's the main problem I have with how President Obama is approaching the whole issue.

The "all of th…

The last time the Earth had a 15-year cooling trend of any kind...

Image
I was asked by a friend to identify the last time the Earth experienced a 15-year cooling trend.  The way I answered this was to use a rolling regression on GISS surface data (R code at the bottom).  Turns out that the last time was before I was born.  The period from February 1958-January 1973 (cooling of -0.00188ºC per decade) was the last 15-year cooling trend in GISS surface data.  Every 15-year period since has shown a warming trend of some magnitude—and yes, that even includes trends starting in 1998.

Now as to the last time the Earth showed a statistically significant 15-year cooling trend, well, that's a bit tougher to answer.  The code I'm using cannot account for autocorrelation, which means that it is biased toward showing significant time series trends when in reality the trends are not significant.  The original code also didn't compensate for multiple comparisons.  Even using that extremely lenient standard of significance, however, the last time the Earth ex…

Ignorance, blindness, and outright misinformation

Image
A childhood acquaintance on Facebook posted a link to a CBN News article that serves as a good example of what is wrong with conservative news media.  Written by Dale Hurd, it is a mash-up of science denier canards with little in the way of actual science or evidence.

The first paragraph sets the tone, making fun of the scientists who were trapped in Antarctic ice.  Nowhere does Hurd mention HOW the scientists were trapped: A storm packed sea ice into the bay their ship was in.  Now this can happen at any time of the year but it doesn't mean that the ice is growing.  It's summer down in Antarctica, a time when Antarctic sea ice melts from ~19 million km2 in September down to ~2-3 million km2 by March.  That leaves plenty of broken pack ice for winds to blow around, especially in the early part of the melt season such as December when the ship was trapped.  So the irony is that those scientists were trapped by MELTING sea ice, an irony completely lost on Hurd.

Hurd's claim:…

Polar vortex and global warming

Image
I've had several people to use the current cold weather in the US as "proof" that global warming isn't happening. Unfortunately for those arguments, they're pure bunk.

First, the Eastern US and Canada do not represent the entire planet. The December 2013 global map of average temperature anomalies show this:


While the eastern US and Canada are cold, the rest of the planet is relatively warm, with only a few areas (e.g. the Middle East) colder than the 1951-1980 average.  This same pattern has been in place since November 2013 and I expect that the January 2014 map won't change much.   [As expected, it did not.  Here's the January 2014 map:]



Again, the Eastern US was far below average whereas the rest of the planet, especially much of the Arctic was far above average.]  This demonstrates the importance of looking at the global temperature data, rather than just the weather in your backyard when contemplating global warming.


Second, the current weather pa…