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Author Topic: Do you still believe climate change is not mainly due to mankind?  (Read 5982 times)

Offline CPT ArkAngel

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Science under attack, this is the title of a documentary made by the president of the Royal Society, sir Paul Nurse. Everyone should watch this. I think it is an honest point of view.

http://topdocumentaryfilms.com/science-under-attack/

About GM food, the main problem i see is the behaviour of some large companies in the way they promote their products, not on the GM food in itself, unless it is not properly tested...
« Last Edit: 07/07/2011 05:28:22 by CPT ArkAngel »


 

Offline frethack

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Yep...I still believe that our changing climate (that has *never* been at equilibrium) is mainly natural, with some effect from man that has yet to be quantified.
 

Offline CPT ArkAngel

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What is the natural cause according to you?

Humans produce 7 times more CO2 than nature. We produce heat too. When you will admit it, it may be too late. The sun is not more active now than before... Some large and very powerful companies see this as a treat to their growth and their power.
 

Offline CliffordK

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Excellent film, although a bit long for YouTube.

In reality, science enters in all aspects of our lives, whether you have genetically modified corn, or corn that has had 20,000 years of specific breeding programs.
Plastic?
Metals?
Paints?
Airplanes?
Cars?

At some point in the film they said:
   "Climate change in the past was very gradual."
   "Now it is very rapid."

Yet, that is certainly hotly debated with some theories indicating that the Cretaceous Period may have ended with catastrophic climatic change occurring in a single day.
Year to year climate variation and decade to decade climate variation is also very high, at least on a local scale.

The show said that the "Net" puts "Conspiracy theories on level terms with peer reviewed science".

Perhaps the Net actually puts the "Conspiracy Theories" one step above the peer reviewed science.  The problem is that much of the peer reviewed science hasn't incorporated the idea of a virtual library yet.  So searches of information turns up the peer reviewed articles in abstract form only.  One then has a choice of paying $30 for a 3 page article, or spending a day heading to the local research library to hunt down the article, then a few $$ at the copy machine.  And, prior experience indicates that only about 1/10 articles are really good articles...  so the gems are suddenly $300 for a 3 page article!!!!  $100 per page might be good for the scientific community, but not for hobbyists. 

You can pick up as many of the conspiracy theories in full for FREE!!!


Later the film talked about "Science Ideals and the Trust in Evidence". 

Yet, that is perhaps the core of the entire climate debate, that we have diverged from actual evidence, and the new science is now models rather than evidence.  And while there are significant improvements in the models, there are still a few significant holes in them. 

The short-term hour by hour weather forecasts discussed in the film were all well and good.  Why didn't they have a better presentation of unobstructed screens?  But, the accuracy of long-term forecasts plummets considerably.  In fact, when I freeze the images, I see a lot more clouds and different patterns in the model (bottom half of the screen) than in the Observed (top half of the screen).


As new data comes in, the models are continuously modified to match the data.  Then they use the match of the modified model to the data set to justify the model, when it has been forced to match that data.

There was a discussion of spliced data sets, good or bad.  And, unfortunately there are a lot of spliced data sets.  Instruments change.  Recording methods change.  Instruments fail and are replaced with newer versions (especially true with the space observations).

There is also a lot of confounding data.
For example:
Hot weather is correlated with dry weather and droughts. 
So, does the hot temperature cause the dry weather, or is there a third variable such as displacement of jet streams that is causative of both the hot weather and the dry weather?
Then, if another exogenous force causes hotter weather without changing the jet streams, will you also get dryer weather?

I suspect this may be in part the cause of the divergence in the tree ring data (along with things like thinning, fire control, increased CO2, etc).  However, if the model poorly matches the current data, it necessarily brings into question the match of the model to historical data.  The only exception I would allow would be recent data that is confounded by the Nuclear Age.
 

Offline frethack

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At some point in the film they said:
   "Climate change in the past was very gradual."
   "Now it is very rapid."

Yet, that is certainly hotly debated with some theories indicating that the Cretaceous Period may have ended with catastrophic climatic change occurring in a single day.

I dont think that rapid climate change is that hotly debated anymore.  Most paleoclimate studies that have been published in the past 10 years have shown episodic warming and cooling - sometimes beneficial, sometimes catastrophic, sometimes both.  In the past 10,000 years, there have been more than a few that happened in the span of just a decade (Younger Dryas, 8.2 ka event, etc.).


Yet, that is perhaps the core of the entire climate debate, that we have diverged from actual evidence, and the new science is now models rather than evidence.  And while there are significant improvements in the models, there are still a few significant holes in them. 

The NCEP Renalysis data set is pretty funky before 1950, and still not trustworthy before the late 70s or early 80s.  Until the satellite era, ocean data was taken by ships crossing, and while there were quite a few ship, they mostly stick to certain shipping lanes.  So we have strong data for those areas, but the rest of the "data" for the reanalysis set is modeled from the data that exists.  Until after WWII, the dataset is *horrible*, I toss it out automatically unless Im interested in a specific region that is well covered.  Before 1979, the stratospheric portion of the data is weak, so youre really restricted to 30 years of data that you can actually trust - from a dataset that spans 153 years.  This set is one of the most popularly used datasets in climate science, and even I have to use it because it (and the Met Offices similar sets) is really the best option available at this point.

What is the natural cause according to you?

Humans produce 7 times more CO2 than nature. We produce heat too. When you will admit it, it may be too late. The sun is not more active now than before... Some large and very powerful companies see this as a treat to their growth and their power.

I have no disagreement with you that humans produce a LOT of CO2, and that it has warmed the atmosphere.  However, Ive watched and studied the sun for the past four years, and there is a reason that it is classified as a variable star.  Weve launched a pretty hefty arsenal of solar satellites over the past 10 years, and our understanding of the sun has increased exponentially.  Just the last 3 years have nullified the Lean Model, the solar model used in most GCMs and other regional models.  We discovered that ultraviolet light can vary 400-600% more than expected, which has significant implications for ozone and the stratosphere as a whole (which in turn effects the troposphere...where the weather is).

 

Offline yor_on

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Frethack. I have a totally different view of the weather satellite programs, and I expect all climate scientists to have it too. Take a look here for a recent example Defunding of NOAA Weather Satellites Means Goodbye To the 7-Day Forecast.

It's the other way around actually. Don't ask me why, because it seems a pretty dumb thing to do. Economics and probably not enough support for NOOA. Which will degrade one of the worlds absolutely best climate centers to a second grade facility in a matter of ? Ten years?

Europe do try to take up some of the slack but they are not in the same league as NASA used to be. Europe's Next Weather Satellite Passes Vacuum Test. And that is a problem, to me it seems like everyone would win on having better data, except possibly the true deniers, those that don't want to see at all, leaving it to 'divine providence' and their own wallet of course.
 

Offline yor_on

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Offline CliffordK

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Frethack. I have a totally different view of the weather satellite programs, and I expect all climate scientists to have it too. Take a look here for a recent example Defunding of NOAA Weather Satellites Means Goodbye To the 7-Day Forecast.

OUCH!!!!!!!!!!

I actually snag a 10 day forecast off from weather.com which I believe derives information from the Federal Weather Services.  Actually, I think the government should do a better job at distributing their own information, and insist on better references from companies and websites that use their information. 

For ordinary 9-5 corporate life, a weather forecast of a day or two is sufficient.  Heck, sticking one's hand out the window is often good enough.

However, AGRICULTURE depends on accurate forecasts.  If one needs about 7 days to cut, dry, bale, and put one's hay in the barn.  And, a week or two of non-stop rain can cause a 100% crop loss.  Then an accurate forecast is vital, and has real economic consequences.

The other thing about this whole global warming debate is that our data is very poor.  

We are analysing temperature shifts on the order of fractions of a degree over a century, using thermometers that are accurate to about 1C or 2F, and multiple poorly controlled instrument and methodology changes.  We have about 30 years of TSI data from a half a dozen satellites, some with decaying instruments, and nobody is quite sure how all the data should be spliced together.  Likewise, sea ice volumes are calculated based on models rather than observations with a several year gap between the last satellite and the current satellite.  

Much of our data comes from about a 30 year snapshot taken in the middle of major 60 year climate cycles, Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO).

Personally I'm suspicious about the changeover from MSU to AMSU data around 1998.

What we need more than anything is better datasets and data continuity.

Having a critical mind doesn't mean refusing to collect the data that one needs.
 

Offline CliffordK

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This one might be of interest too.

U.S., Europe worlds apart on climate science coverage by Midwest Energy news.

Personally I think too much media support for Global Warming is partly to blame for the scepticism. 

There is too much of a knee-jerk reaction to blame all bad weather on global warming.  And, that leads people to look for alternative explanations, and a labyrinth of data and opinions.

Has anybody over there ever thought to question whether two back-to-back coldest winters in a century were actually caused by global warming?  Of course, I do understand the theory of a shift of jet streams and the gulf stream.  But, still one should take such assertions with a skeptical mind.

Likewise, there are many people trying to connect this spring's tornado outbreaks with global warming, but again the evidence for such a connection is very weak.

Even so, one needs to think of such weather events as probabilistic. 
We've certainly had hot, cold, wet, and dry weather in the past.  So, any single event could just be random.  Global warming, or otherwise climate change is only obvious when looking at long-term trends.  And, even so, there are major 60+ year weather cycles that can confound the studies.
 

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