On Fri, 29 Jan 2016 23:57:38 +1100, Gordon Levi says...
> I supplied Dr Spencer's lucid explanation of anthropogenic global
> warming _theory
It's not an explanation of HIS theory, you dumb fucking shut-in. He's
explaining the THEORY that OTHERS have. God, what a bonehead.
That money your mommy spent to educate you and then having you sit at home
all day postulating, was wasted.
Do you want me to show you the thousands of words and video of him
explaining the OPPOSITE of what you THINK he's explaining?
Dr. Roy Spenser does NOT believe in this theory, you dolt. He's explaining
the theory OF AGW.
I can explain religion, moron... that doesn't mean I believe in God.
You were at the same place the following is... why didn't you post THIS?
***********************************************************
My Global Warming Skepticism, for Dummies (or Gordon Levi)
I receive many e-mails, and a recurring complaint is that many of my
posts are too technical to understand. This morning's installment
arrived with the subject line, "Please Talk to Us", and suggested I
provide short, concise, easily understood summaries and explanations
"for dummies".
So, here's a list of basic climate change questions, and brief answers
based upon what I know today. I might update them as I receive
suggestions and comments. I will also be adding links to other sources,
and some visual aids, as appropriate.
Deja vu tells me I might have done this once before, but I'm too lazy
to go back and see. So, I'll start over from scratch. (Insert smiley)
It is important to understand at the outset that those of us who are
skeptical of mankind's influence on climate have a wide variety of
views on the subject, and we can't all be right. In fact, in this
business, it is really easy to be wrong. It seems like everyone has a
theory of what causes climate change. But it only takes one of us to be
right for the IPCC's anthropogenic global warming (AGW) house of cards
to collapse.
As I like to say, taking measurements of the climate system is much
easier than figuring out what those measurements mean in terms of cause
and effect. Generally speaking, it's not the warming that is in
dispute... it's the cause of the warming.
If you disagree with my views on something, please don't flame me.
Chances are, I've already heard your point of view; very seldom am I
provided with new evidence I haven't already taken into account.
1) Are Global Temperatures Rising Now?
There is no way to know, because
natural year-to-year variability in global temperature is so large, with
warming and cooling occurring all the time. What we can say is that
surface and lower atmospheric temperature have risen in the last 30 to
50 years, with most of that warming in the Northern Hemisphere. Also,
the magnitude of recent warming is somewhat uncertain, due to problems
in making long-term temperature measurements with thermometers without
those measurements being corrupted by a variety of non-climate effects.
But there is no way to know if temperatures are continuing to rise
now... we only see warming (or cooling) in the rear-view mirror, when we
look back in time.
2) Why Do Some Scientists Say It's Cooling, while Others Say the
Warming is Even Accelerating?
Since there is so much year-to-year (and
even decade-to-decade) variability in global average temperatures,
whether it has warmed or cooled depends upon how far back you look in
time. For instance, over the last 100 years, there was an overall
warming which was stronger toward the end of the 20th Century. This is
why some say "warming is accelerating". But if we look at a shorter,
more recent period of time, say since the record warm year of 1998, one
could say that it has cooled in the last 10-12 years. But, as I
mentioned above, neither of these can tell us anything about whether
warming is happening "now", or will happen in the future.
3) Haven't Global Temperatures Risen Before?
Yes. In the longer term,
say hundreds to thousands of years, there is considerable indirect,
proxy evidence (not from thermometers) of both warming and cooling.
Since humankind can't be responsible for these early events is
evidence that nature can cause warming and cooling. If that is the case,
it then opens up the possibility that some (or most) of the warming in
the last 50 years has been natural, too. While many geologists like to
point to much larger temperature changes are believed to have occurred
over millions of years, I am unconvinced that this tells us anything of
use for understanding how humans might influence climate on time scales
of 10 to 100 years.
4) But Didn't the "Hockey Stick" Show Recent Warming to be
Unprecedented?
The "hockey Stick" reconstructions of temperature
variations over the last 1 to 2 thousand years have been a huge source
of controversy. The hockey stick was previously used by the IPCC as a
veritable poster child for anthropogenic warming, since it seemed to
indicate there have been no substantial temperature changes over the
last 1,000 to 2,000 years until humans got involved in the 20th Century.
The various versions of the hockey stick were based upon limited amounts
of temperature proxy evidence - primarily tree rings - and involved
questionable statistical methods. In contrast, I think the bulk of the
proxy evidence supports the view that it was at least as warm during the
Medieval Warm Period, around 1000 AD. The very fact that recent tree
ring data erroneously suggests cooling in the last 50 years, when in
fact there has been warming, should be a warning flag about using tree
ring data for figuring out how warm it was 1,000 years ago. But without
actual thermometer data, we will never know for sure.
5) Isn't the Melting of Arctic Sea Ice Evidence of Warming?
Warming, yes... manmade warming, NO. Arctic sea ice naturally melts back
every summer, but that melt-back was observed to reach a peak in 2007. But
we have relatively accurate, satellite-based measurements of Arctic (and
Antarctic) sea ice only since 1979. It is entirely possible that late
summer Arctic Sea ice cover was just as low in the 1920s or 1930s, a
period when Arctic thermometer data suggests it was just as warm.
Unfortunately, there is no way to know, because we did not have
satellites back then. Interestingly, Antarctic sea ice has been growing
nearly as fast as Arctic ice has been melting over the last 30+ years.
6) What about rising sea levels?
I must confess, I don't pay much
attention to the sea level issue. I will say that, to the extent that
warming occurs, sea levels can be expected to also rise to some extent.
The rise is partly due to thermal expansion of the water, and partly due
to melting or shedding of land-locked ice (the Greenland and Antarctic
ice sheets, and glaciers). But this says nothing about whether or not
humans are the cause of that warming. Since there is evidence that
glacier retreat and sea level rise started well before humans can be
blamed, causation is - once again - a major source of uncertainty.
7) IS INCREASING CO2 EVEN CAPABLE OF CAUSING WARMING? THERE ARE SOME
VERY INTELLIGENT PEOPLE OUT THERE WHO CLAIM THAT ADDING MORE CARBON
DIOXIDE TO THE ATMOSPHERE CAN'T CAUSE WARMING ANYWAY. THEY CLAIM
THINGS LIKE, "THE ATMOSPHERIC CO2 ABSORPTION BANDS ARE ALREADY
SATURATED", OR SOMETHING ELSE VERY TECHNICAL. [AND FOR THOSE MORE
TECHNICALLY-MINDED PERSONS, YES, I AGREE THAT THE EFFECTIVE RADIATING
TEMPERATURE OF THE EARTH IN THE INFRARED IS DETERMINED BY HOW MUCH
SUNLIGHT IS ABSORBED BY THE EARTH. BUT THAT DOESN'T MEAN THE LOWER
ATMOSPHERE CANNOT WARM FROM ADDING MORE GREENHOUSE GASES, BECAUSE AT THE
SAME TIME THEY ALSO COOL THE UPPER ATMOSPHERE]. WHILE IT IS TRUE THAT
MOST OF THE CO2-CAUSED WARMING IN THE ATMOSPHERE WAS THERE BEFORE HUMANS
EVER STARTED BURNING COAL AND DRIVING SUVS, THIS IS ALL TAKEN INTO
ACCOUNT BY COMPUTERIZED CLIMATE MODELS THAT PREDICT GLOBAL WARMING.
ADDING MORE "SHOULD" CAUSE WARMING, WITH THE MAGNITUDE OF THAT
WARMING BEING THE REAL QUESTION. BUT I'M STILL OPEN TO THE POSSIBILITY
THAT A MAJOR ERROR HAS BEEN MADE ON THIS FUNDAMENTAL POINT. STRANGER
THINGS HAVE HAPPENED IN SCIENCE BEFORE.
8 ) Is Atmospheric CO2 Increasing? Yes, and most strongly in the last 50
years... which is why "most" climate researchers think the CO2 rise
is the cause of the warming. Our site measurements of CO2 increase from
around the world are possibly the most accurate long-term,
climate-related, measurements in existence.
9) Are Humans Responsible for the CO2 Rise? While there are short-term
(year-to-year) fluctuations in the atmospheric CO2 concentration due to
natural causes, especially El Nino and La Nina, I currently believe that
most of the long-term increase is probably due to our use of fossil
fuels. But from what I can tell, the supposed "proof" of humans
being the source of increasing CO2 - a change in the atmospheric
concentration of the carbon isotope C13 - would also be consistent
with a natural, biological source. The current atmospheric CO2 level is
about 390 parts per million by volume, up from a pre-industrial level
estimated to be around 270 ppm... maybe less. CO2 levels can be much
higher in cities, and in buildings with people in them.
10) But Aren't Natural CO2 Emissions About 20 Times the Human
Emissions? Yes, but nature is believed to absorb CO2 at about the same
rate it is produced. You can think of the reservoir of atmospheric CO2
as being like a giant container of water, with nature pumping in a
steady stream into the bottom of the container (atmosphere) in some
places, sucking out about the same amount in other places, and then
humans causing a steady drip-drip-drip into the container.
Significantly, about 50% of what we produce is sucked out of the
atmosphere by nature, mostly through photosynthesis. Nature loves the
stuff. CO2 is the elixir of life on Earth. Imagine the howls of protest
there would be if we were destroying atmospheric CO2, rather than
creating more of it.
11) IS RISING CO2 THE CAUSE OF RECENT WARMING? WHILE THIS IS
THEORETICALLY POSSIBLE, I THINK IT IS MORE LIKELY THAT THE WARMING IS
MOSTLY NATURAL. AT THE VERY LEAST, WE HAVE NO WAY OF DETERMINING WHAT
PROPORTION IS NATURAL VERSUS HUMAN-CAUSED.
12) Why Do Most Scientists Believe CO2 is Responsible for the Warming?
Because (as they have told me) they can't think of anything else that
might have caused it. Significantly, it's not that there is evidence
nature can't be the cause, but a lack of sufficiently accurate
measurements to determine if nature is the cause. This is a hugely
important distinction, and one the public and policymakers have been
misled on by the IPCC.
13) If Not Humans, What could Have Caused Recent Warming? This is one of
my areas of research. I believe that natural changes in the amount of
sunlight being absorbed by the Earth - due to natural changes in cloud
cover - are responsible for most of the warming. Whether that is the
specific mechanism or not, I advance the minority view that the climate
system can change all by itself. Climate change does not require an
"external" source of forcing, such as a change in the sun.
14) So, What Could Cause Natural Cloud Changes? I think small, long-term
changes in atmospheric and oceanic flow patterns can cause ~1% changes
in how much sunlight is let in by clouds to warm the Earth. This is all
that is required to cause global warming or cooling. Unfortunately, we
do not have sufficiently accurate cloud measurements to determine
whether this is the primary cause of warming in the last 30 to 50 years.
15) How Significant is the Climategate Release of E-Mails? While
Climategate does not, by itself, invalidate the IPCC's case that
global warming has happened, or that humans are the primary cause of
that warming, it DOES illustrate something I emphasized in my first
book, "Climate Confusion": climate researchers are human, and prone
to bias.
16) Why Would Bias in Climate Research be Important? I thought
Scientists Just Follow the Data Where It Leads Them When researchers
approach a problem, their pre-conceived notions often guide them. It's
not that the IPCC's claim that humans cause global warming is somehow
untenable or impossible, it's that political and financial pressures
have resulted in the IPCC almost totally ignoring alternative
explanations for that warming.
17) How Important Is "Scientific Consensus" in Climate Research? In
the case of global warming, it is nearly worthless. The climate system
is so complex that the vast majority of climate scientists - usually
experts in variety of specialized fields - assume there are more
knowledgeable scientists, and they are just supporting the opinions of
their colleagues. And among that small group of most knowledgeable
experts, there is a considerable element of group-think, herd mentality,
peer pressure, political pressure, support of certain energy policies,
and desire to Save the Earth - whether it needs to be saved or not.
18) How Important are Computerized Climate Models? I consider climate
models as being our best way of exploring cause and effect in the
climate system. It is really easy to be wrong in this business, and
unless you can demonstrate causation with numbers in equations, you are
stuck with scientists trying to persuade one another by waving their
hands. Unfortunately, there is no guarantee that climate models will
ever produce a useful prediction of the future. Nevertheless, we must
use them, and we learn a lot from them. My biggest concern is that
models have been used almost exclusively for supporting the claim that
humans cause global warming, rather than for exploring alternative
hypotheses - e.g. natural climate variations - as possible causes of
that warming.
19) What Do I Predict for Global Temperature Changes in the Future? I
tend to shy away from long-term predictions, because there are still so
many uncertainties. When pressed, though, I tend to say that I think
cooling in our future is just as real a possibility as warming. Of
course, a third possibility is relatively steady temperatures, without
significant long-term warming or cooling. Keep in mind that, while you
will find out tomorrow whether your favorite weather forecaster is right
or wrong, no one will remember 50 years from now a scientist today
wrongly predicting we will all die from heat stroke by 2060.
Concluding Remarks
Climate researchers do not know nearly as much about the causes of
climate change as they profess. We have a pretty good understanding of
how the climate system works on average... but the reasons for small,
long-term changes in climate system are still extremely uncertain.
The total amount of CO2 humans have added to the atmosphere in the last
100 years has upset the radiative energy budget of the Earth by only 1%.
How the climate system responds to that small "poke" is very
uncertain. The IPCC says there will be strong warming, with cloud
changes making the warming worse. I claim there will be weak warming,
with cloud changes acting to reduce the influence of that 1% change. The
difference between these two outcomes is whether cloud feedbacks are
positive (the IPCC view), or negative (the view I and a minority of
others have).
So far, neither side has been able to prove their case. That uncertainty
even exists on this core issue is not appreciated by many scientists!
Again I will emphasize, some very smart people who consider themselves
skeptics will disagree with some of my views stated above, particularly
when it involves explanations for what has caused warming, and what has
caused atmospheric CO2 to increase.
Unlike the global marching army of climate researchers the IPCC has
enlisted, we do not walk in lockstep. We are willing to admit, "we
don't really know", rather than mislead people with phrases like,
"the warming we see is consistent with an increase in CO2", and then
have the public think that means, "we have determined, through our
extensive research into all the possibilities, that the warming cannot
be due to anything but CO2".
Skeptics advancing alternative explanations (hypotheses) for climate
variability represent the way the researcher community used to operate,
before politics, policy outcomes, and billions of dollars got involved.