(Totally OT) Re: DMD 0.175 release

[Don Clugston]

David Medlock wrote:
> John S. Skogtvedt wrote:
> 
>> David Medlock skrev:
>>
>>>
>>> Take heart with global warming.  Its happening on Mars as well so it 
>>> probably a fluctuation in the Sun, not human causes...
>>>
>>> -DavidM
>>
>>
>> If you do a google search it seems it's not quite that simple:
>> http://www.realclimate.org/index.php?p=192
> 
> True, but there is no hard evidence outside computer models that humans 
> are causing any fluctuations in temperature.  Whether it is happening is 
> a separate issue than what is causing it. It would be terribly difficult 
> to prove empirically that human activity is the cause.

(1) It is clear that CO2 concentrations in the atmosphere are increasing 
significantly as a result of human activity.
(2) It is clear that, on its own, these increased CO2 levels will 
increase global temperature by a couple of degrees.
(3) It is known that global temperatures have risen over the last 
hundred years, and particularly over the last 30.
(4) What is completely unknown is, what feedback mechanisms are there in 
the earths climate? Especially cloud formation. Feedback could be 
positive or negative.
(5) The contribution of solar activity is also unknown.

(human activity) + (other causes) + (feedback mechanisms) = (observed 
climate change).

> Also, consider that the total temperature only rose 1 degree in the last 
> century and hurricane season was(comparatively) a flop this year.

Be careful with that "only". Only a few degrees difference in global 
temperature makes the difference between the current climate and the 
last ice age.

> Even if you believe C02 emissions are doing it, remember that 100 years 
> ago the automobile had just entered the market.  Who knows what we will 
> be using in 100 more!

Indeed. But the fundamental issue is this:
For most of human history, we've implicitly treated the earth as 
essentially infinite, and human activity as a small perturbation. That 
is no longer a good assumption; for some topics, it's an extremely poor 
assumption. It's that simple.

> Politicians and anti-capitalists love the theories though.  It lets them 
> pass laws to make you live the way they want you to.  Makes them feel 
> good but its mostly junk science.  The ban on DDT has killed millions of 
> mostly children in Africa, but it was too banned on junk science and 
> only after first world countries had used it successfully.

There's a lot of junk science around, no doubt about it, in all kinds of 
directions. An interesting one is that a lot of air pollution publicity 
was funded by cigarette companies (so that people would blame their 
chronic bronchitis and lung cancer on environmental factors, instead of 
the toxic chemicals they were pumping directly into their lungs twenty 
times per day...).