Tag Archives: guessing

Australia Heat Wave BBC Mistakes

I must be a tiny bit sensitive.  When I see a climate related article that makes absolutely no sense, I tend to overreact.  A case in point, a recent BBC article on hot weather in Australia.  The article says:

“Australia has been warming up by about 0.9C [a year] since 1910,” Dr Braganza told the BBC.

Australian temperature records go back to 1910.

The emphasis added by the writer is clearly a silly stupid mistake, the world warmed about 0.9 degree C in the 20t century and not 0.9 degree C per year for 105 years.  Australia hasn’t started acting like Venus, although on a warm day in January it might seem so.

Australia’s average annual weather bounces around quite a bit which is not particularly surprising as regional climate varies much more than the world as a whole. Just three years ago the average for the year was a full degree C lower than in 2013.

Australia hasn’t been steadily rising for a hundred years.  It’s had warm years and cold ones with a slow rise over the century  as this data  from the Australia Bureau of Meteorology demonstrates:

https://i2.wp.com/www.bom.gov.au/tmp/cc/tmean.aus.0112.7747.png

Clearly the person writing the article didn’t understand how climate works or she wouldn’t have made such a silly mistake…and I guess that is my complaint.

It is interesting that Australia is warming faster than the rest of the Southern Hemisphere.  Most 20th century warming occurred over land in the Northern Hemisphere as this University of East Anglia  Climate Research Unit (CRU) graph demonstrates:

https://i0.wp.com/mclean.ch/climate/figures/Hemis_comb_av_80-04.gif

Still it is a bit of a puzzle.  I wonder why the little ecosystem that is Australia has acted as it has.  Perhaps it’s simply a short term trend.  It’s difficult to tell with such a small data set and such a big country.

I’d suspect the older Australia data to be of poor quality.  Most of the best data on climate is new data.  I’d be a bit surprised if they had good land based data even 50 years ago.  It’s a big place…so any comment about a trend that began in 1910, when the data began, is a bit of a guess.  Probably a SWAG number?!

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Sea Level Questions Continue

Yesterday, I read a piece in our local newspaper discussing the problems rising sea level will cause.   Built into the article were two assumptions, both of which are probably  incorrect.

  • Assumption 1 – Sea level could rise by as much as a meter by the year 2100
  • Assumption 2 – Man can take actions to alter this in some significant way.

When I look at sea level data I see confusion.   Today was no exception.   My inquiry began with a look at Satellite data courtesy of  Colorado University.

Sea level, according to CU, is rising at a rate of about 3.2 millimeters a year (plus or minus 12.5%).  That’s about an 1/8 of an inch per year or about a foot per century.  Plus or minus an inch or two.  Not exactly a meter, but coastal regions will have difficulties.  Sea level has been rising since the Little Ice Age ended some 250 years ago.   If I had land in Key West, I’d be worried.

But sea level in Key West isn’t rising at 3.2mm/yr, it’s rising at 2.24 mm/yr.  And the trend has been steady for the 100 years of the data.

chart: Mean Sea Level Trend, 8724580 - Key West, Florida

Key West may be under water at some date in the future, but the rate of change appears to be much less than predicted by IPCC scientists.  I suppose Key West could be an oddity, but it’s unlikely.   I visited the NOAA web site and checked many places I thought might be interesting.   Places like Bermuda, Honolulu, San Francisco, Venice.   Yep, Venice, well Trieste, it’s just across the bay.

http://tidesandcurrents.noaa.gov/sltrends/trends/270-061.png

Trieste’s rate is less than 40% of the Satellite predicted rate.

1.24/3.4 = .397 or 39.7%

The margin for error is half the satellite data rate (.2 mm vs .4mm)

Every place I checked  had a trend rate that was less than the satellite data.   In most cases the predicted margin for error was less than the satellite data too.    A few select data points have a longer history too. I tabulated the results

City                                            rate of change       data history

San Francisco                             2.01 mm/yr       160 years                                              Honolulu                                       1.50 mm/yr       110 years                                                     New York                                     2.77 mm/yr       120 years                                                 Bermuda                                       2.04 mm/yr         70 years                                          Narvik, Norway                       -2.06 mm/yr          60 years                                          Cochin, India                              1.71 mm/yr          70 years                                                Hong Kong                                  2.92 mm/yr          60 years                                        Nagasaki, Japan                        2.20 mm/yr         45 years                                          Sydney, Australia                     0.65 mm/yr         130 years                                     Auckland, New Zealand         1.29 mm/yr         120 years

This data doesn’t tell the full story of the confusion.  Individual sites provide lots of conflicting data.   Honolulu has been trending down since about 2002:

chart: Mean Sea Level Trend, 1612340 - Honolulu, Hawaii

The NOAA presentation of the Bermuda data a bit odd:

chart: Mean Sea Level Trend, 2695540 - Bermuda,

Most of the increase shown in Bermuda happened before 1960.  Had the data set begun in 1955 instead of 1934 the trend line would have shown nearly no net change.  Sea level rose fairly rapidly from 193o until 1955 and has been relatively stable since then.  Go figure.

Virtually every city I checked showed a less ominous looking trend line than the satellite data.  This land based data has it’s limitations.   Many international cities have tiny data sets, particularly in South America and Africa.   Only one data point exists for all of Antarctica

chart: Mean Sea Level Trend, 999-003 - Argentine Islands, Antarctica

I would argue that the Antarctica data doesn’t really suggest a trend but NOAA calculates the trend at  1.43mm/yr.  When I look at the data I see no net changes since 1960.  Sounds kind of like Bermuda’s data to me?

Something is wrong.   Every land site I checked showed less overall change than the satellite data.   How can that be?   The satellite data is an average for the whole world.   Some specific locations should be higher and some places should be lower.

Northern locations like Alaska and Norway are showing reduced sea level due to reduced gravitational pull from the Arctic Ice Sheet (presumably).  Where are the equatorial places that are compensating for that reduction?   I can’t make sense of the data.   Satellite data and measurements at land interfaces don’t tell the same story.

Sea level is extraordinarily difficult to calculate.   Sea level changes in one part of the world can take years and years  to impact the ecosystem.  I understand that storms and changing ice sheets impact the data.  Change that can take decades to correct.

WHY is the satellite data very nearly ALWAYS significantly higher than the land data?

The Satellite data has been higher every year since the data began in 1993.   Every year! Most places I have checked disagree by about 1 mm per year.  After 20 years of data the sources disagree with each other by about 20 mm.  or about .78 inches.  The longer this condition exists, the less I trust the data sets.

It really is difficult to make accurate predictions about sea level if you don’t have the ability to accurately graph the underlying trend line.  Sea level, almost certainly,  has been rising since the end of the Little Ice Age some 250 years ago.  But by how much?   Almost no statistical data exists before the Civil War. I suspect SWAG.

Sea level has been steadily rising for probably 250 years.   How much has been man’s impact? I don’t know and I’ll go a step further…nobody knows!

I am not convinced that we have the tools necessary to accurately predict the future course of events as it relates to sea level.    Sea level appears to be an indicator that follows rather than leads climate change.   How much of today’s changes in sea level were impacted by global temperatures of 20 or 50 or 100 years ago?  I don’t know.  I see guessing here, there and everywhere.

IPCC scientists might have the trends right….but even that is…I fear …. a guess.

 

 

 

 

 

 

Al Gore’s Wild Ass Arctic Ice Guess

Never let the facts get in the way of a good story.

Mr. Gore spent lots of time talking about Arctic Ice in his 2006 pseudo documentary film, An Inconvenient Truth.  We got to see Al ride on a Nuclear Submarine and watch as he saw first hand how the Navy measured ice thickness in the Arctic.

Sometimes it’s good to be Vice President.

Mr. Gore talked about how he was able to use his influence to get very important confidential Arctic Ice data released.   He then provided the data in graph form.   Mr. Gore narrated while the graph was displayed.   He said that the ice had been reduced by 40% in 40 years.  It was catchy and easy to remember.  What a story.

But was it true?

No.  Well I’m sure he rode on the sub and the Navy has data.   Most everything else is simply a part of his story.  And it’s a good story.

Mr. Gore (in the film) presented a charts that showed a steady decline in the ice mass in the Arctic.  He lectured to the audience while the slide was being displayed.   He claimed the ice had decreased 40% in 40 years.   Here’s the chart:

https://i2.wp.com/web.ncf.ca/jim/ref/inconvenientTruth/full/00_44_25.jpg

Mr. Gore’s chart says the ice declined by 1.5 million square kilometers from a base of a bit less than 14.    I’ll help Mr. Gore with the arithmetic.  1.5/13.7 = 11%.

11% in 35 years is not exactly 40% in 40 years.   Mr. Gore’s careless use of data  really is old news.  Why, one might wonder, am I bringing this up now?

Well I always suspected the entire calculation was a wild ass guess but I didn’t have good independent confirmation.   I suspected Sub based data would be spotty and incomplete.  But I wasn’t sure.  Now I am confident the entire section of the film was a fabrication (except for the submarine ride).  A good story and nothing else.

Visit the National Snow and Ice Data Center  (NSIDC) web site.   They provide lots of statistical information about  ice in the Arctic (and Greenland and the Antarctic too).   The NSIDC has this to say about Arctic Ice thickness:

While satellite observations have shown a decline in Arctic Ocean sea ice extent since the late 1970s, sea ice is highly mobile, and a decrease in extent does not necessarily imply a corresponding decrease in ice volume. Observations of thickness (which allows  calculation of volume) have been limited, making it difficult to estimate sea ice volume trends. The European Space Agency (ESA) CryoSat satellite was launched in October 2010 and has enabled estimates of sea ice thickness and volume for the last three years.

The best information is only 3 years old.  Wow.  Everything before that is a guess or so says The National Snow and Ice Data Center.  These University of Colorado scientists are the recognized experts.  Mr. Gore released his film in May of 2006.  Most of his data ended before 2005.

Wild Ass Guess Confirmed.

Greenland’s Ice Sheet Melting — A Typical SWAG Story

Last Friday,  CNN and NPR ran a story about ice melt in Greenland.   A new study says the rate of melting in Greenland  is  less than the rate shown in other studies.   The NPR story had a less optomistic tone than the CNN story.  Both stories noted the new reduced level, and both emphasized  global warming as a still  urgent issue, just a little less troubling in the near future.

An article written last fall talked about how  Greenland  is melting faster because the ice is darker because of discoloration caused by air pollution.

Science is messy and it’s going to get things wrong from time to time as it progresses.  Older UN reports have said increased snowfall will offset the increased melting in Greenland. That is the nature of the Scientific Wild Ass Guess.  Lot of guesses, and frequently the guesses disagree.   Some necessarily will be wrong. These are difficult subjects, and guessing is a necessary part of the process.

I have long suspected that government funding encourages wild guessing.

A scientist gets a job studying a perceived problem, in the form of a grant from the government.   If the study shows the perceived problem was less important than thought…..no new funding.  No funding means it’s time to apply for a new grant.

This prejudice towards a specific outcome, can and frequently does impact the results of studies.  The  study will almost certainly raise new questions, and have new uncertainties.  New guesses.   If a conservative guess means unemployment, and a wild one continued employment…..well?

Governments need a problem to be immediate and serious.  Any study that does not feed that government need will likely lead to unemployment.

When I look at IPCC data, I see guessing  everywhere;  the sun, clouds, oceans, visible air pollution.   The IPCC  predicted that 2025 would be a degree C warmer than 1990 (in their original assessment in 1992) and it would happen in a fairly linear manner of about .3 degree C per decade.   And the world did warm a bit for about 6 years….and then it stopped.

The world has warmed less than predicted with high carbon dioxide levels.  Of course, that doesn’t prove them wrong, natural climate variation could be  masking a real problem.  They chose to make wild guesses in a climate system that is naturally unstable. The politics of climate science encourages such guessing.  In 2007 they lowered the rate to .2 degree C increase  per decade.  Wrong again, at least so far.

My best guess: the IPCC is wrong.  All the wild predictions for 50 or 100 years are just that, wild guesses.  I hope they are wrong…because I don’t think society can fix the problem the IPCC sees  in a way the IPCC would like.  But then I’m guessing too.