Monday, March 24, 2014

Harry Bulkeley: A few questions about global warming -- Answered

An opinion writer (a retired judge) asked a few questions in his Galesburg, IL local paper, and I'll provide some answers here.  As always, I encourage you to read the original.

The good judge, like the usually informative Mr. Krauthammer, starts off on a very wrong foot, with bad philosophy of science.  There are many facts in science -- the earth is round, the sun is hot, there is a greenhouse effect, and CO2 is a greenhouse gas.  All can be questioned -- but not in the trivial way that Bulkeley and Krauthammer seem to think.  'I question it' is trivial, and pointless.  If you have a _scientific_ question about these things, or any other, it is because, and only because, you have scientific evidence that the 'fact' is false.

Climate change, as even commenters in agreement with Bulkeley note, is indeed a fact.  Climate changes, that's a fact.  One of the tasks of science is to try to understand the hows and whys of that fact.

Let's see about the questions:
1) Average temperature has indeed gone up the past 15 years.  This is a question, apparently, because the author didn't bother to look at the data. One can experiment with time periods and trends at NOAA/NCDC.
http://www.ncdc.noaa.gov/cag/time-series/global/globe/land_ocean/1/2/1880-2014  
It's worth paying attention to the fact that climate trends are defined on 30 year periods, not 15.  Some discussion of why this is the case is at
http://moregrumbinescience.blogspot.com/2009/01/results-on-deciding-trends.html
2) 'is global warming bad?'.  Well, that'll depend on who you are and where you are, and what you rely on.  If you're a poor person living near sea level, it'll be bad.  If you own a ski mountain now and want to cover it with condos, you may well be happy.  If you're a farmer, changes to temperature, humidity, and rainfall will probably make life more difficult.

But rather than investigate an answer to his question, Bulkeley goes off to doing some cherry-picking, perhaps not realizing that he's doing so.  (But I dare say ignorance of the science in a scientific discussion, is no more an excuse than ignorance of the law is when you arrive in court.)  There are two sorts of ice involved in discussion of 'the ice caps', and failing to keep track of them separately leads you to error.  The kind he does mention is sea ice -- which is floating on the ocean, and most of which (by area) freezes and melts every year.  But there is also land ice -- the huge ice sheets on Greenland and Antarctica.  The ice sheets are melting, and this is contributing to sea level rise.

Sea ice, he ignores his own admonition about using a single year.  Rephrased, and scientifically accurate -- Fall 2013 Arctic ice volume was 50% greater than the extreme record minimum that occurred in 2012, which places it, still, among the very lowest fall volumes on record.

But, to continue his take of looking at single years, did Fall 2013's increase continue?  Well, no.  March 2014 is back down to one of the lowest volumes ever seen for that month, in a tie with 2013.  That 'increase' was awfully short-lived.  No surprise to scientists -- weather happens.  If you're interested in Arctic sea ice, an excellent place to watch is http://neven1.typepad.com/blog/


3) "if there is global warming, is it man-made?" this one does indeed have some technical issues, none of which he mentions, instead presenting readers with 'he-said she-said'.  Some experts (no names) say one thing, some other (also unnamed) experts say another.  And no sense given as to where the balance of opinion among experts is.  It's overwhelmingly on the side that most of the warming since about 1950 is indeed to to human activity.

4) "If it is man-made, is there anything the United States can do about it?"  Not so much a question for a physical scientist like myself, but I see he's got total confidence that cutting CO2 emissions would ruin the economy.  Economists use models too.  It's puzzling that he places absolute trust in those models, and absolute distrust in climate models.  Nobody, in any case, has argued for the US to cut all CO2 emissions in a single day.  Straw man.

5) "Finally, is there any chance that the rest of the world will cut their emissions?"  Which he straightforwardly answers 'no'.

Myself, I don't rely on my psychic powers to know what everybody else in the world will do.  He may if he wants.  But that's certainly not science.  Some countries, and regions of countries, are already reducing their CO2 emissions, which gives the trivial disproof of his answer.

After this he makes some freelance comments, including:
"The Earth has had higher and lower temperatures and higher levels of CO2 without being destroyed."

I've yet to encounter anybody saying that the earth would be 'destroyed'.  Certainly not in science.  It's routine, in a geological sense, for Galesburg to be under a mile or two of ice -- which is how it has spent most of the last 700,000 years.  Perfectly routine, geologically, doesn't destroy the earth, but I dare say the residents would still not be happy with this magnitude of climate change.

Unfortunately, it does seem to be that magnitude, though opposite direction, of climate change that we are now looking at.  When Galesburg was under a mile or more of ice, atmospheric CO2 levels were about 200 ppm.  The melt off of that ice was accompanied by an 80 ppm increase, to 280 ppm.  In the last 200 years, humans have increased it to 400 ppm.  Climate is not a simple as we might like, but this is clearly a kick to the system that is not small.

6 comments:

Dan Pangburn said...

Search keyword AGW unveiled (no embedded space) to discover what has driven climate change since before 1900.

Robert Grumbine said...

Dan: If you want to post a link to your personal blog (1 article only?) that has relevant material, go ahead. It's http://agwunveiled.blogspot.com/2013/12/calculated-meanglobal-temperatures-1610.html

See my link policy -- http://moregrumbinescience.blogspot.com/2008/08/linking.html

The use of cumulative sums has a number of problems, and it doesn't appear you avoid them. See http://tamino.wordpress.com/2011/08/03/cumulative-sums/ for some discussion of why.

It also appears you're using material from "climaterealists", originally named 'co2skeptics'. That doesn't look like a good source (follow this link to see what that reaction).

EliRabett said...

Well done.

Dan Pangburn said...

Robert - Not posting the link was simply to avoid tripping spam traps.

With a little more time at my site, you may have realized that the 'cumulative sums' point as described by Tamino does not apply. The equation uses conservation of energy and the numerical integration calculates the energy change over time which is observed as temperature change.

I have posted stuff at climaterealists and refer to my postings there, mostly as historical background.

All of the analysis at my site is my own. I use data reported by credible agencies for temperature anomalies, CO2 level and sunspot numbers.

The analysis calculates average global temperature anomalies since before 1900 with R2>0.90 and credible trends back to the depths of the Little Ice Age.

There are many sub-links in that paper and possibly a lot of stuff that you have never seen before. I welcome any and all technical critique.

Robert Grumbine said...

Unfortunately, the cumulative sums issues for time series analysis do apply. They apply because you are correlating two different series, only one of which you apply cumulative sums to, among other things.

You also are not applying the first law (conservation of energy), notwithstanding your claim. It's fairly straightforward -- if you're applying the first law, you add up the energy in and subtract the energy out and energy storage. You have no figures for any of these quantities.

What you do have is sunspot numbers, which are not simply an energy measure. There are reconstructions of solar output -- energy -- variations over this period. The fact that you ignore them in favor of sunspot counts suggests bad things about the rest of your work.

Since the foundation is wrong, the rest of the work is also. The conclusion might ultimately be correct, stopped clocks and all, but you can't get to there from what you started.

The sun is certainly important to climate. I have a paper in review now which investigates a particular case. But there's more involved to making that case than you show. (Not least, mine actually works with energy.)

Dan Pangburn said...

I don’t know if it will help to see where I am at but, like you, I don’t doubt that there is a greenhouse effect (for the planet; for greenhouses, not so much) and CO2 is a ghg. However, one of the things that I discovered is that whether CO2 change is considered or not made no significant difference in the coefficient of determination, R^2 .

Apparently what appears to you to be a correlation is actually a calculation of R^2. That is merely a measure of how well the equation matches the measurements. As you can see from the high R^2 and also the graphs, the equation does extremely well.

The first law is applied just like you said it should be. Application of the first law of thermodynamics is described on page 2 of reference 2 which is at http://climatechange90.blogspot.com/2013/05/natural-climate-change-has-been.html . As stated in the AGWunveiled paper, the SB change due to average global temperature (AGT) change is adequately accounted for by the sunspot number time-integral, i.e. (T(i)/Tavg)^4 is set equal to one.

Most, if not all, who looked at sunspots, stopped looking when they found that TSI did not correlate. The sunspot number time-integral makes an excellent correlation. An explanation of how it works is given in the AGWunveiled paper. In brief, magnetic fields from the sunspots shield the planet from galactic cosmic rays which reduces low altitude cloud cover. Less low altitude clouds means lower albedo, and also, higher average cloud altitude, lower average cloud temperature, less thermal radiation from the planet. The effects work together so more sunspots results in a warming planet; fewer sunspots a cooling planet. I made a rough calculation of the sensitivity of AGT to low altitude clouds at http://lowaltitudeclouds.blogspot.com/

Good luck with your paper.

I also have a paper in review (two approvals so far). It should be out this summer, perhaps sooner.