[Vision2020] PCEI Climate Change Forum Discussion On Local Blog

[Paul Rumelhart]

Ted Moffett wrote:
> Paul et. al.
>  
> The science article from the journal Nature at URL below examines the 
> theory that the observed climate warming of the past 30 years (and 
> even back to the 17th century) is due to solar variability, using 
> satellite data, the "clear readings from space," as you phrase it.  
> The article can be accessed in full with a subscription.  But this 
> quote from the review is rather easily understood by a layperson, in 
> terms of any definite conclusion that the data supports the theory 
> that the warming of the past 30 years is due to solar variability:
>  
> http://www.nature.com/nature/journal/v443/n7108/abs/nature05072.html
>  
> Variations in the Sun's total energy output (luminosity) are caused by 
> changing dark (sunspot) and bright structures on the solar disk during 
> the 11-year sunspot cycle. The variations measured from spacecraft 
> since 1978 are too small to have contributed appreciably to 
> accelerated global warming over the past 30 years. In this Review, we 
> show that detailed analysis of these small output variations has 
> greatly advanced our understanding of solar luminosity change, and 
> this new understanding indicates that brightening of the Sun is 
> unlikely to have had a significant influence on global warming since 
> the seventeenth century.

There seem to be three things going on here that I, at least, seem to be 
getting confused.  There is 1) the 11-year sunspot cycle, 2) the 
research indicating that the sun may be brightening by 0.05% per decade, 
and 3) aberrations in sunspot activity that are also alleged to have a 
climate impact (such as the "Maunder Minimum").

I can't tell by the summary for this article if it's addressing 1, or 1 
and 2.  The satellite data originally appeared to show that there was no 
increase between sunspot cycle minimums, due to a gap in coverage 
between two satellites.  Once data from other satellites that overlapped 
this gap was taken into account, the research showed a positive trend of 
0.05% per decade.  There have been 30 decades between 1700 and present, 
and 1.0005 ^ 30 == 1.015109 (or a 1.5% increase in total solar 
irradiance).  That's assuming, of course, that it's a continuing trend 
and not a fluke in these three sunspot cycles that the satellites have 
data for.  I'll have to find a copy of the article to see if it's 
talking about a 1.5% increase, or no increase (except between minimums 
and maximums of the 11-year sunspot cycle).

The Maunder Minimum is interesting, because it appears to have coincided 
with the coldest part of the Little Ice Age.  The wikipedia article on 
it also states that studies indicate that the sun spends up to a quarter 
of it's time in one of these minima periods.

So, my logic goes like this: minimums in sunspot cycle activity can 
cause catastrophic climate change (albeit in the opposite direction).  
It would seem likely that maximums in sunspot cycle activity can cause 
catastrophic climate change, too.  Increases in total solar irradiance 
would also affect the climate.

Nasa Study:  
http://www.nasa.gov/centers/goddard/news/topstory/2003/0313irradiance.html
Wikipedia page on the Maunder Minimum: 
http://en.wikipedia.org/wiki/Maunder_minimum

> -------------
> Regarding the magnitude of climate forcing due to anthropogenic CO2 
> (and other) emissions asserted by the IPCC Fourth Assessment report 
> from 2007, which I assume represents the scientific predictions you 
> doubt, I suggest you take your skepticism to realclimate.org 
> <http://realclimate.org>.  I have received personal responses to my 
> humble queries from some of the scientists hosting this website, much 
> to my surprise.  And the discussions on climate science issues are 
> often very enlightening and balanced, with basic assumptions, 
> facts and theories run through the gauntlet of skepticism.

I'll do a little more reading there.  If I can get up the courage, and 
my reading hasn't already convinced me that my question is horribly 
stupid, I'll post it there and see what happens.

> Also, the effect of global dimming (which is given scant attention in 
> the media), the climate cooling effect of human sourced pollution, 
> indicates we may be masking a significant amount of the warming effect 
> of greenhouse gas emissions.  Thus when we cease the pollution from 
> coal fired plants, for example, which release sulfate aerosols that 
> cool the climate, the masking effect of global dimming will be 
> removed, and climate warming may increase.  Given this potential, the 
> climate may warm significantly when we lower our carbon 
> footprint.  Anyway, no one realistically thinks we are going to 
> dramatically lower our greenhouse gas emissions (which we must) for 
> decades.

I hadn't seen much about global dimming.  This is interesting.  I'll do 
some reading on it.

>  
> We may need to engineer removal of CO2 from the atmosphere, or block 
> solar radiation.  These extreme engineering proposals are 
> controversial, but under serious discussion given the seriousness of 
> the problem.  Plans to adapt to a warmer climate are prudent, given 
> these efforts may not work.  Ironically, there are proposals to 
> deliberately add "pollution" to the upper atmosphere to cool the 
> climate, in a way similar to how coal fired plants can contribute to 
> global dimming due to sulfate aerosols, to ward off the worst effects 
> of the greenhouse gas emissions from coal fired plants:
>  
> http://www.pbs.org/wgbh/nova/sun/dimm-nf.html
>  
> http://www.realclimate.org/index.php/archives/2006/04/global-dimming-and-climate-models/

Interesting stuff.  I'm glad somebody's working on it.

>  
> --------------------
> You obviously doubt that human sourced climate variables are the main 
> contemporary influence on warming, and have implied this assessment is 
> motivated by intentions other than pure objective scientific research 
> (wording such as "the global warming party line" implies political 
> motivations rather than following the results of objective unbiased 
> scientific research).  Human beings are human beings, and no doubt 
> there are motivations other than the pursuit of objective scientific 
> research to hype the magnitude of anthropogenic climate change, just 
> as there are motivations among some very powerful commercial interests 
> to inject doubt and uncertainty into the scientific findings 
> indicating the severity of the problem.  However, I trust there are a 
> sufficient number of competent and ethical scientists working on the 
> science of climate change to provide a reasonable balance to the 
> conclusions of the IPCC, that is not slanted by those seeking to make 
> a name, achieve fame, pad their wallets, promote political agendas, or 
> promote their career, by either being global warming skeptics or 
> global warming doomsayers.  My "trust" may be misplaced.

Maybe it's a limitation in myself, but when you throw too many variables 
into the pot at the same time, it makes it hard for me not to be 
somewhat skeptical of conclusions reached using that data.  It's not so 
much that I doubt the contemporary influences on warming, it's that I'm 
skeptical of the conclusions reached about their magnitudes.

When I talk about the "global warming party line", I'm talking more 
about the media and casual conversations than I am about a conspiracy 
among scientists to milk this for all that it's worth.  It's just my 
opinion that there is a "party line" that, if you veer too far away from 
it, tends to heap ridicule and/or scorn your way.  It reminds me of the 
reactions I got directly following 9/11 when I stated my opinions that 
we should make our response an international one and not a lone wolf 
aggressive one.  Back then, you were thought to be a terrorist 
sympathizer hell bent on ruining America.  Here, you tend to be a 
"global warming denier" even if you're only putting forth a skeptical 
outlook and not an actual denial of the science involved.  I also get 
the idea that we're thought to be colluding with air conditioning 
manufacturers or something.  Like I want the Earth to get too warm to 
live on comfortably.

Skepticism is a good thing.  It keeps us from running amok when someone 
tells us something.

>  
> Note to Chas, in case you are reading:
>  
> You are probably correct I am wasting my "breath" in addressing the 
> science of climate change on Vision2020.  Consider the results of my 
> posts addressing PCEI's Climate Change Forum: not a single Vision2020 
> comment from anyone involved with PCEI, unless I missed it.  If PCEI 
> is not following and contributing to environmental discussions on 
> Vision2020, then Vision2020 must not be viewed as relevant to 
> environmental discussions impacting the public, scientific or otherwise.

I'd also like to say that I agree with Chas that I appreciate your 
posts, even if we don't always agree.

Paul

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