Temperatures of the lower troposphere: models vs. observations

Update: Just a note that this post was not intended to be anything more than a “back of the envelope” look at how global tropospheric temperatures correlate with surface temperatures as I understand the models. I’m hoping I can look more deeply into this topic in the future, mostly as an educational experience for myself.

Climate models predict that the lower troposphere should warm globally approximately 1.2 times more than the Earth’s surface (1.5 in the tropics). Yet at present, satellite temperature data does not seem entirely consistent with those predictions.

The following graph plots GISS land/sea temperatures against UAH satellite temperatures for the lower troposphere from 1979-2010 for comparison purposes.  The red line represents the GISS data and the green line plots the actual UAH temperature data. The blue line represents the GISS temperatures scaled by a factor of 1.2 and therefore shows the predicted value of the global tropospheric temperatures according to the models.

Lower Troposphere Temps (Actual vs. Predicted) (using UAH/GISS)

As can be seen, the difference between the predicted tropospheric temperatures and actual temperatures (i.e., the difference between the green and blue lines) appears to be substantial. I am not attempting to determine at this point whether the difference is statistically significant or not (I suspect it is), but that can be a topic for future post.

Curry faces her accusers – again

In Plato’s “Apology”, Socrates says the following of his accusers:

…for they do not like to confess that their pretence of knowledge has been detected–which is the truth; and as they are numerous and ambitious and energetic, and are drawn up in battle array and have persuasive tongues, they have filled your ears with their loud and inveterate calumnies.

I couldn’t help recalling these words as I read the over-heated comments in this recent thread at RealClimate where Dr. Judith Curry faced her own set of accusers, apparently upset with her for having the audacity to associate with climate auditor Stephen McIntrye (and his “ilk”) and also for encouraging mainstream climate scientists to rebut the arguments contained in A.W. Montford’s recent book “The Hockey Stick Illusion” which documents, from a skeptical point of view, issues with paleo-reconstructions of past temperatures using tree-ring proxies. The book focuses on the famous “hockey stick” graph, denigrated by climate skeptics as climate science’s biggest failure and lauded by AGW proponents as one of its strongest pieces of evidence in support of unprecedented 20th century warming.

The thread in question was initiated by a review of “The Hockey Stick Illusion” by pro-AGW blogger Tamino, a review in which he appears to have misrepresented and misunderstood several key points in Montford’s book (see here, for example). Enter Ms. Curry who rushed out a review of the review, giving it a grade of C-. What ensued was both hysterical and nauseating.

When did “Global Warming” become “Climate Change”?

July was a difficult month personally, with a family crisis (still ongoing) and an extremely busy work schedule  But no complaints here.  If I’m going to continue to blog, I better get used to doing it in the face of some stiff time constraints, as work and family life are not likely to become any less demanding in the near future, as far as I can see.

To start things rolling again, I thought I’d do something short and fun.

Anyone who has been following the “Global Warming”, er, “Climate Change” debate for any length of time now has probably noticed that the former moniker seems to be losing ground in favour of the latter. But when exactly did it happen?

To answer this question, I decided to compare the number of times the terms “Global Warming” and “Climate Change” appear in news articles indexed by Google News since 2000. Here are the results:

Toasts and Tributes: June 23, 2010

I’ve decided to add a new feature to the blog: Toasts and Tributes.

Every few weeks (or as often as I can manage)  I’ll toast one or more people who have demonstrated the courage to “do the right thing” even when it is not always popular.

This week’s recipients of this honour go to:

1) Missouri Governor Jay Nixon

Despite leading to possible increases in health insurance premiums, last week Nixon signed a bill requiring insurance companies to cover the cost of therapy – up to $40,000 per year to the age of 18 – for autistic children.   This should be sufficient to cover the cost of 20 hours of ABA therapy per week for a child, often considered the minimum amount necessary to achieve meaningful results.

Jay, not only are you doing the right thing from an ethical point of view, essentially giving autistic children a chance at a meaningful life, but you are also doing the right thing from a financial point of view as well.  Studies  (e.g., here) indicate that the total cost to society per autistic person due to lost productivity and the need for specialized services can be anywhere from $3-4 million over a lifetime.   Early intervention can reduce that cost considerably.  It has been shown that ABA therapy alone can reduce the cost by almost half  (Jacobsen et al, 1998; Jarbrink and Knapp, 2000).

Global temperatures: magnitudes and trends

One thing I often see in media reporting on climate change is confusion regarding the difference between the magnitude of temperatures for individual years over the past decade (expressed as anomalies) and the trend in temperatures over the past decade.

It is not uncommon, for example, for proponents of global warming to berate climate skeptics for stating that the world has experienced a modest cooling over the last 10 years.  After all, how can that be true when so many years of the last decade have been among the warmest this century? Doesn’t that imply that significant global warming is still occurring? Well, some people certainly think so.

City of Lakes: Victim of Global Warming?

Last week the Vancouver Observer published an article  describing the impacts of climate change on various parts of Asia. The full article is available here.

Prominently featured in the article is a description of Udaipur, the so-called “City of Lakes”, located in the Rajasthan state of India. The author of the piece has the following to say about the current state of Udaipur and its lakes:

One telling example of the drought is occurring in Udaipur, a beautiful, historical city that lies amongst centuries-old man-made lakes created by various maharajas. Udaipur has been called the City of Lakes. It’s a misnomer now.

If you’ve ever seen the movie Octopussy, you’ll remember James Bond speeding across a gorgeous blue lake with a wedding cake palace in the background. That was Lake Pichola in Udaipur. Shockingly, the lake is now almost dry and has been for a few years. The rains don’t come anymore, and under the searing sun and growing population, the demand for water is too great.

About the Rajasthan state in general it is said:

Throughout Rajasthan, the state southwest of Delhi, water issues are at critical levels. It’s not just a recent phenomenon either – drought has ravaged the state for the past 10 years, withering crops, drying up wells and virtually roasting cattle before they are even butchered.

While mention is given to the role of population pressures on water supply in the region, it is clear from the article that the author is primarily attributing the decline of Udaipur’s lakes to anthropogenic global warming (the end of the article makes the link to CO2 explicit).

Natural Climate Swings Have Significant Effect on Glaciers: Nature

There is an interesting article on glacial retreat at Nature.

The article discusses a recent study concluding that global warming’s contribution to shrinking glaciers has likely been overstated. The article implies that other factors, such as the Atlantic Multidecadal Oscillation (AMO), can account for a significant amount of observed glacial retreat.

See here for the full article.