Wednesday, March 28, 2007
Dr. Steven Quiring Q&A

1) Global warming is a very politically charged issue. Is there
currently any unbiased research in the field?

Although global warming is very politically charged, there is unbiased
research on global warming. The best source of information on global
warming is the Intergovernmental Panel on Climate Change (more
commonly referred to as the IPCC). The IPCC recently (February 2,
2007) released the Summary for Policy Makers for the 4th Assessment
report (http://www.ipcc.ch/SPM2feb07.pdf).

Skepticism is an important part of the scientific process, especially
since one of the main flaws of science is that it is carried out by
humans. Humans are imperfect, biased, and we make mistakes. Therefore,
no single experiment or published paper provides enough evidence to
conclusively prove something as fact. Thankfully a lot of time, money,
and effort has been invested into the scientific research on global
warming. There are a lot of things that we know with a great deal of
certainty because they have been checked and rechecked by many
different scientists over many years. Much of this research is
summarized in the IPCC's Fourth Assessment report. This report was
produced by some 600 authors from 40 countries. Over 620 expert
reviewers and a large number of government reviewers also participated
in the process. The IPCC report provides a thorough review of the
state of climate science in regards to global warming and it provides
an unbiased view of what is known (and what uncertainties remain to be
solved). In addition the report qualifies all of the statements that
it makes so it provides the policy makers (and other non-climate
scientists) with an estimate of certainty.



2) I have read that the cause for concern is not necessarily that the
earth is warming, but the rate at which it is warming. What is the
real story?

There are two main causes for concern. The first is the global
temperature (likely the highest in the last 1300 years). The second is
the rate of warming (unprecedented in the last 10,000 years). Although
the magnitude of temperature increase is cause for concern, what may
be more important from an adaptation and mitigation perspective is the
rate at which this warming is occurring. The faster the warming the
less time there is for humans, animals, and plants to adjust to these
changes. The IPCC predicts that 1.8 to 4.0 C of warming by 2100. If
this amount of warming were predicted to occur over, for example, the
next 1000 years, it would not be as grave a concern.



3) Skeptics say that global warming is not real, that the earth simply
goes through cycles and we are in the warm phase of one of those
cycles. What do you think about this?

It has been demonstrated that the warming that has occurred during the
20th century is a result of human activities. In fact, were it not for
natural volcanic cycles, the amount of warming during the 20th century
would have been much greater. (see my answer to question 8 for more
details on this).



4) In Al Gore's documentary, he shows a chart that measures carbon
dioxide and temperature levels taken from Antarctic ice core samples
that date back 650,000 years. He claims that the chart shows how
rising carbon dioxide levels cause temperature to increase. But when
the chart is viewed up close, it looks like the opposite is true. It's
clear that the two are related, but do scientists know what is
actually happening?
Excerpt from http://www.realclimate.org/index.php...-in-ice-cores/
:
"This is an issue that is often misunderstood in the public sphere and
media, so it is worth spending some time to explain it and clarify it.
At least three careful ice core studies have shown that CO2 starts to
rise about 800 years (600-1000 years) after Antarctic temperature
during glacial terminations. These terminations are pronounced warming
periods that mark the ends of the ice ages that happen every 100,000
years or so.
Does this prove that CO2 doesn't cause global warming? The answer is
no.
The reason has to do with the fact that the warmings take about 5000
years to be complete. The lag is only 800 years. All that the lag
shows is that CO2 did not cause the first 800 years of warming, out of
the 5000 year trend. The other 4200 years of warming could in fact
have been caused by CO2, as far as we can tell from this ice core
data.
The 4200 years of warming make up about 5/6 of the total warming. So
CO2 could have caused the last 5/6 of the warming, but could not have
caused the first 1/6 of the warming.
It comes as no surprise that other factors besides CO2 affect climate.
Changes in the amount of summer sunshine, due to changes in the
Earth's orbit around the sun that happen every 21,000 years, have long
been known to affect the comings and goings of ice ages. Atlantic
Ocean circulation slowdowns are thought to warm Antarctica, also.
From studying all the available data (not just ice cores), the
probable sequence of events at a termination goes something like this.
Some (currently unknown) process causes Antarctica and the surrounding
ocean to warm. This process also causes CO2 to start rising, about 800
years later. Then CO2 further warms the whole planet, because of its
heat-trapping properties. This leads to even further CO2 release. So
CO2 during ice ages should be thought of as a "feedback", much like
the feedback that results from putting a microphone too near to a
loudspeaker.
In other words, CO2 does not initiate the warmings, but acts as an
amplifier once they are underway. From model estimates, CO2 (along
with other greenhouse gases CH4 and N2O) causes about half of the full
glacial-to-interglacial warming.
So, in summary, the lag of CO2 behind temperature doesn't tell us much
about global warming. [But it may give us a very interesting clue
about why CO2 rises at the ends of ice ages. The 800-year lag is about
the amount of time required to flush out the deep ocean through
natural ocean currents. So CO2 might be stored in the deep ocean
during ice ages, and then get released when the climate warms.]
To read more about CO2 and ice cores, see Caillon et al., 2003,
Science magazine"



5) Gore also says that the ice of the northwest arm of Antarctica is
cracking and melting. What about the rest of the continent? I have
heard it is actually thickening for the first time in 6000 years. Is
this true?

This is a difficult question to answer. It is very difficult to
accurately model or measure the mass balance of Antarctica. However a
recent paper in Science (http://www.sciencemag.org/cgi/content/
abstract/311/5768/1754) suggests that between 2002-2005 the mass of
the ice sheet decreased significantly, at a rate of 152 ± 80 cubic
kilometers of ice per year, which is equivalent to 0.4 ± 0.2
millimeters of global sea-level rise per year. Most of this mass loss
came from the West Antarctic Ice Sheet.

However, as the world warms there may be increased precipitation over
Antarctica which could cause a thickening of parts of the ice sheet.
There is an ongoing debate in the literature about what these issues.



6) It seems like Gore presents a lot of correlations in his film, but
doesn't actually prove causation. What is your take?

No single source of data is sufficient to prove or disprove global
warming. Showing pictures of glaciers receding or talking about
drowning polar bears is all well and good, but Gore's documentary only
shows a few examples of the impacts of global warming. That is why the
IPCC Fourth Assessment report is such an important document. It
summarizes many all of the observed trends in snow cover, sea-ice,
glaciers, etc. and it demonstrates that many of these trends are
related to human activities. I encourage you to review this document
for more details.



7) The film suggests that global warming is responsible for massive
hurricanes, deadly heat waves, and other extreme weather events. Is
this possible? Is there even enough evidence to make such a
conclusion?

Global warming is not the 'cause' of any single hurricane, heat wave,
or other extreme weather event (the climate is not a simple system, it
is a dynamic quasi-chaotic system that simultaneously responds to a
multitude of forcings and feedbacks). For example, we can't say that
global warming 'caused' Hurricane Katrina, however as the world warms
due to the increasing concentrations of greenhouse gases, we know that
some aspects of the climate system will change. For example, the IPCC
Fourth Assessment Report concludes that it is very likely (see
explanation below) that the frequency of warm spells/heat waves will
increase over most land areas during the 21st century. They also
conclude that it is likely (see explanation below) that intense
tropical cyclone activity will increase during the 21st century.



8) Is there any evidence that actually shows how much we are
contributing to rising temperatures around the world? There is
probably a lot of debate about this, but is there any consensus at
all?

Yes. It is possible to calculate the magnitude of human influence on
the climate. These studies are known as attribution studies and they
look at observed temperature changes to determine if they are
quantitatively consistent with the natural and human forcings. The
IPCC 4th Assessment report concluded that it is very likely
(probability of occurrence 90%) that most of the observed increase
in globally averaged temperatures since the mid-20th century is due to
the observed increase in anthropogenic greenhouse gas concentrations
(e.g., Carbon Dioxide).

Excerpts from the Summary for Policy Makers for the 4th Assessment
report (http://www.ipcc.ch/SPM2feb07.pdf):

"Changes in the atmospheric abundance of greenhouse gases and
aerosols, in solar radiation and in land surface properties alter the
energy balance of the climate system. These changes are expressed in
terms of radiative forcing, which is used to compare how a range of
human and natural factors drive warming or cooling influences on
global climate. Since the Third Assessment Report (TAR), new
observations and related modelling of greenhouse gases, solar
activity, land surface properties and some aspects of aerosols have
led to improvements in the quantitative estimates of radiative
forcing.

The understanding of anthropogenic warming and cooling influences on
climate has improved since the Third Assessment Report (TAR), leading
to very high confidence (at least a 9 out of 10 chance of being
correct) that the globally averaged net effect of human activities
since 1750 has been one of warming, with a radiative forcing of +1.6 W
m-2.

{Radiative forcing is a measure of the influence that a factor has in
altering the balance of incoming and outgoing energy in the Earth-
atmosphere system and is an index of the importance of the factor as a
potential climate change mechanism. Positive forcing tends to warm the
surface while negative forcing tends to cool it. In this report
radiative forcing values are for 2005 relative to pre-industrial
conditions defined at 1750 and are
expressed in watts per square metre (W m-2).}

It is likely that increases in greenhouse gas concentrations alone
would have caused more warming than observed because volcanic and
anthropogenic aerosols have offset some warming that would otherwise
have taken place. The observed widespread warming of the atmosphere
and ocean, together with ice mass loss, support the conclusion that it
is extremely unlikely that global climate change of the past fifty
years can be explained without external forcing, and very likely that
it is not due to known natural causes alone."

From:
http://battopinion.blogspot.com/

Deforestation on a global scale removes trees which
are "carbon fixers" that capture CO2 from the air
and convert it into "tree trunks" and later into buried
coal and ... eventually even oil. In other words, man
has, in this century, removed the earths main CO2
filter .. .converting the forests into farmland, and
cities for people. Add to that, all the output from
power plants, and cars, and you have 2 reinforcing
factors that are probably much more effective than
either alone. The fact that this mirrors a natural
process ... the earth cooling from volcanic activity
over billions of years, combined with the retreat of
the primeval forests ... confuses the real issue.
The real issue is that the lack of a good CO2 filter,
caused by mechanical deforestation, can temporarily
generate global warming .. but then all the evaporated
water, goes across high mountain ranges and falls
out as huge amounts of snow ... and enucleates
another ice age ... basically a form of "nuclear
winter", caused by unnatural processes. This
destroys food resources .. and civilizations, in
the same way it destroyed Mammoths while
standing there chewing grass. You can't see this
with algebra and peer reviews. It is just common
sense. And the idea that "government reviewers"
are doing a good job ... that is absurd. All they
want to do is collect a pay check for going to
meetings and eating cheese. That is the biggest
pack of con-artists, liars, plagarists, fake data
creators, narcissists who undermine each others
reputations, and spend a lot of time hopping
around motel bedrooms late at night, in the
history of the world. Lord help us if that's the
best we've got.

johns