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Maybe you can do me a favor and pull out the citation of the actual physical evidence that shows that greenhouse gases are the "cause" of global warming?
Or are you unable to support your own beliefs?
All charts you said? What about a chart provided by Nasa?
http://data.giss.nasa.gov/gistemp/2007/
It keep going up. Look at the graph.
Look at the chart now.
Are we warming or colder then 2000?
If greenhouse gases (CO2) was the "cause" and we have more CO2 then ever before why are we colder today then in 2000? If these greenhouse gases "caused" the warming, why aren't we colder today then just in 2000?
What is the physical evidence that shows that these greenhouse gases are the "cause" of global warming?
And what are you doing? You are making assumptions without and physical evidence to back it up.Are you being totally ignorant on purpose? As we have explained to you in this thread and in other threads, for non-anthropogenic climate change (ie climate change before the industrial revolution) warming leads CO2 because it the warming is not being driven by CO2. As you well know CO2 increases AFTER the oceans warm and CO2 solubility decreases.
HOWEVER, in the current warming (as in the last century or so), CO2 is LEADING temperature:
And what are you doing? You are making assumptions without and physical evidence to back it up.
If what you were saying is true we should be warmer then in 2000. Clearly we are cooling.
Lets look at the last 10,000 years or so, shall we? The period is called the Holocene.
Clearly we are cooling. Today is on the left.
http://en.wikipedia.org/wiki/Holocene_climatic_optimum
Hmm, now onto this petition which is linked in the fox story. It looks like I meet the qualifications required to sign this petition, and since I know diddly about climate change I have to question the merit of the petition. I'll give it a go though and report back to see if my name is included on the list.
Upon further reading, there's a bit of scrutiny IRT this petition already due to fraud. If anything is a political ploy, this petition is its poster. That's not to say that I have an opinion on climate change one way or another.
eta: http://en.wikipedia.org/wiki/Oregon_Petition
How are measurements of CO2 and temperature NOT physical evidence?
Secondly, it is warmer now than 2000:
http://en.wikipedia.org/wiki/Temperature_record_since_1880
Notice that 2001, 2002, 2003, 2004, 2005, 2006 and 2007 are ALL warmer than 2000. Care to apologize for lying?
Co2 levels are physical evidence. But do you agree or disagree that these levels follow warming or precede it?
And if they follow it how can they be the cause?
Maybe you can do me a favor and pull out the citation of the actual physical evidence that shows that greenhouse gases are the "cause" of global warming?
Or are you unable to support your own beliefs?
The reason the Earths surface is this warm is the presence of
greenhouse gases, which act as a partial blanket for the longwave
radiation coming from the surface. This blanketing is known as
the natural greenhouse effect. The most important greenhouse
gases are water vapour and carbon dioxide. The two most abundant
constituents of the atmosphere nitrogen and oxygen have
no such effect. Clouds, on the other hand, do exert a blanketing
effect similar to that of the greenhouse gases; however, this effect
is offset by their refl ectivity, such that on average, clouds tend to
have a cooling effect on climate (although locally one can feel the
warming effect: cloudy nights tend to remain warmer than clear
nights because the clouds radiate longwave energy back down
to the surface). Human activities intensify the blanketing effect
through the release of greenhouse gases. For instance, the amount
of carbon dioxide in the atmosphere has increased by about 35%
in the industrial era, and this increase is known to be due to human
activities, primarily the combustion of fossil fuels and removal
of forests. Thus, humankind has dramatically altered the
chemical composition of the global atmosphere with substantial
implications for climate.
During the last four decades, the rate at which
scientists have added to the body of knowledge of atmospheric
and oceanic processes has accelerated dramatically. As scientists
incrementally increase the totality of knowledge, they publish
their results in peer-reviewed journals. Between 1965 and 1995,
the number of articles published per year in atmospheric science
journals tripled (Geerts, 1999). Focusing more narrowly,
Stanhill (2001) found that the climate change science literature
grew approximately exponentially with a doubling time of 11
years for the period 1951 to 1997. Furthermore, 95% of all the
climate change science literature since 1834 was published
after 1951. Because science is cumulative, this represents
considerable growth in the knowledge of climate processes and
in the complexity of climate research. An important example
of this is the additional physics incorporated in climate models
over the last several decades, as illustrated in Figure 1.2. As a
result of the cumulative nature of science, climate science today
is an interdisciplinary synthesis of countless tested and proven
physical processes and principles painstakingly compiled
and verifi ed over several centuries of detailed laboratory
measurements, observational experiments and theoretical
analyses; and is now far more wide-ranging and physically
comprehensive than was the case only a few decades ago.
The high-accuracy measurements of atmospheric CO2
concentration, initiated by Charles David Keeling in 1958,
constitute the master time series documenting the changing
composition of the atmosphere (Keeling, 1961, 1998). These
data have iconic status in climate change science as evidence of
the effect of human activities on the chemical composition of
the global atmosphere (see FAQ 7.1). Keelings measurements
on Mauna Loa in Hawaii provide a true measure of the global
carbon cycle, an effectively continuous record of the burning of
fossil fuel. They also maintain an accuracy and precision that
allow scientists to separate fossil fuel emissions from those due
to the natural annual cycle of the biosphere, demonstrating a
long-term change in the seasonal exchange of CO2 between
the atmosphere, biosphere and ocean. Later observations of
parallel trends in the atmospheric abundances of the 13CO2
isotope (Francey and Farquhar, 1982) and molecular oxygen
(O2) (Keeling and Shertz, 1992; Bender et al., 1996) uniquely
identifi ed this rise in CO2 with fossil fuel burning (Sections 2.3,
7.1 and 7.3).
To place the increase in CO2 abundance since the late
1950s in perspective, and to compare the magnitude of the
anthropogenic increase with natural cycles in the past, a longerterm
record of CO2 and other natural greenhouse gases is
needed. These data came from analysis of the composition of air
enclosed in bubbles in ice cores from Greenland and Antarctica.
The initial measurements demonstrated that CO2 abundances
were signifi cantly lower during the last ice age than over the
last 10 kyr of the Holocene (Delmas et al., 1980; Berner et al.,
1980; Neftel et al., 1982). From 10 kyr before present up to
the year 1750, CO2 abundances stayed within the range 280
± 20 ppm (Indermühle et al., 1999). During the industrial era,
CO2 abundance rose roughly exponentially to 367 ppm in 1999
(Neftel et al., 1985; Etheridge et al., 1996; IPCC, 2001a) and to
379 ppm in 2005 (Section 2.3.1; see also Section 6.4).
with simultaneous changes in a whole suite of forcings.
In the early years of detection and attribution research, the
focus was on a single time series the estimated global-mean
changes in the Earths surface temperature. While it was not
possible to detect anthropogenic warming in 1980, Madden
and Ramanathan (1980) and Hansen et al. (1981) predicted it
would be evident at least within the next two decades. A decade
later, Wigley and Raper (1990) used a simple energy-balance
climate model to show that the observed change in global-mean
surface temperature from 1867 to 1982 could not be explained
by natural internal variability. This fi nding was later confi rmed
using variability estimates from more complex coupled oceanatmosphere
general circulation models (e.g., Stouffer et al.,
1994).
Such model-predicted fi ngerprints of anthropogenic climate
change are clearly statistically identifi able in observed data.
The common conclusion of a wide range of fi ngerprint studies
conducted over the past 15 years is that observed climate changes
cannot be explained by natural factors alone (Santer et al.,
1995, 1996a,b,c; Hegerl et al., 1996, 1997, 2000; Hasselmann,
1997; Barnett et al., 1999; Tett et al., 1999; Stott et al., 2000). A
substantial anthropogenic infl uence is required in order to best
explain the observed changes. The evidence from this body of
work strengthens the scientifi c case for a discernible human
infl uence on global climate.
The realisation that Earths climate might be sensitive to the
atmospheric concentrations of gases that create a greenhouse
effect is more than a century old. Fleming (1998) and Weart
(2003) provided an overview of the emerging science. In terms
of the energy balance of the climate system, Edme Mariotte
noted in 1681 that although the Suns light and heat easily pass
through glass and other transparent materials, heat from other
sources (chaleur de feu) does not. The ability to generate an
artifi cial warming of the Earths surface was demonstrated in
simple greenhouse experiments such as Horace Benedict de
Saussures experiments in the 1760s using a heliothermometer
(panes of glass covering a thermometer in a darkened box) to
provide an early analogy to the greenhouse effect. It was a
conceptual leap to recognise that the air itself could also trap
thermal radiation. In 1824, Joseph Fourier, citing Saussure,
argued the temperature [of the Earth] can be augmented by
the interposition of the atmosphere, because heat in the state
of light fi nds less resistance in penetrating the air, than in
repassing into the air when converted into non-luminous heat.
In 1836, Pouillit followed up on Fouriers ideas and argued
the atmospheric stratum exercises a greater absorption
upon the terrestrial than on the solar rays. There was still no
understanding of exactly what substance in the atmosphere was
responsible for this absorption.
In 1859, John Tyndall (1861) identifi ed through laboratory
experiments the absorption of thermal radiation by complex
molecules (as opposed to the primary bimolecular atmospheric
constituents O2 and molecular nitrogen).
And how do you explain that other planets, such as Mars, experienced the same warming trend during that period?As I have said several times, for the current warming coincident with the industrial revolution CO2 levels lead warming. This is shown in the figure I posted from Stanford.
For warmings before the industrial period CO2 initially lags warming. This is "physical evidence" that the current warming is NOT the same as previous warmings. Obviously these previous warmings 100,000's of years ago were not caused by man. They are primarily driven by changes in incident soalr radiaiton due to orbital variations. CO2 is a feedback mechanism in these cases. When CO2 is emited from the oceans it amplifies the effect of solar warming.
Clearly the current warming is caused by a different mechanism from previous warmings, as CO2 is LEADING temperature and incoming solar radiation is DECREASING.
PS Why do you keep posting the plot of Holcene temperature variations that how that current temperatures are WARMER than any period in the past 10,000 years? Do you not understand the plot?
Co2 levels are physical evidence. But do you agree or disagree that these levels follow warming or precede it?
And if they follow it how can they be the cause?
Great post. I'm sure joe will understand it better now. I have a naysayer question that came up on a questionable website (bogus really) I was just looking at. The GHGs noted in this thread make up a very small % of the atmosphere and the greenhouse effect is largely due to water (right?), why would these minute concentration increases have any effect on warming?As I have said several times, for the current warming coincident with the industrial revolution CO2 levels lead warming. This is shown in the figure I posted from Stanford.
For warmings before the industrial period CO2 initially lags warming. This is "physical evidence" that the current warming is NOT the same as previous warmings. Obviously these previous warmings 100,000's of years ago were not caused by man. They are primarily driven by changes in incident soalr radiaiton due to orbital variations. CO2 is a feedback mechanism in these cases. When CO2 is emited from the oceans it amplifies the effect of solar warming.
Clearly the current warming is caused by a different mechanism from previous warmings, as CO2 is LEADING temperature and incoming solar radiation is DECREASING.
And how do you explain that other planets, such as Mars, experienced the same warming trend during that period?
Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says
Great post. I'm sure joe will understand it better now. I have a naysayer question that came up on a questionable website (bogus really) I was just looking at. The GHGs noted in this thread make up a very small % of the atmosphere and the greenhouse effect is largely due to water (right?), why would these minute concentration increases have any effect on warming?
The reason I'm curious about this is due to the graphs posted that show significant recent increases in CO2, where it's looking pretty damming compared to avg global temps of the past. But, when I consider that this increase makes up <2% of the total atmosphere it causes me to wonder.
eta: disclaimer, I'm fully aware that the above may be inaccurate. I'm just going on what I read.
Co2 has increased before those warming period. Co2 level have been increasing for more than a century now. Admit you have been wrong about the "not data after 2000".
Really? Maybe you can show this evidence that shows the CO2 levels increased before warming?
Or should I just take your word for it?
Really? Maybe you can show this evidence that shows the CO2 levels increased before warming?
Or should I just take your word for it?
Thank you for the excellent answer and for making it easy to understand. I won't even say where I was reading earlier because I don't want to link such a bogus site.Water vapor is fairly non-intuitive issue. Water vapor does not drive the climate it responds to other climate forcings and reacts to them. The amount of water vapor in the atmosphere is almost entirely determined by the temperature.
In simple terms: warm air can hold more water vapor than cold air (which is why the air is dry in winter and moist in summer). Let's say you warm the Earth 0.5C through additional CO2. The warmer air now has the ability to hold more water vapor, water vapor is also a greenhouse gas, so now the extra water vapor warms the air by another 0.4C. Now since the air is even still warmer we get even more water vapor, and now the earth warms by an additional 0.3C etc. So while we only added enough CO2 to warm the planet by 0.5C we also get 0.4C + 0.3C + 0.2C warming from water vapor and in the end the temperature goes up by 1.5C. This is called, water vapor feedback and is critical to our understanding of the climate.
Anyone who makes the argument that CO2 is only 0.03% of the atmosphere and therefore cannot effect the climate clearly knows nothing about simple physics. The property of the atmosphere that determines temperature is its transparency to infrared radiation. Air (ie Nitrogen and Oxygen) is essentially completely transparent to IR radiation. CO2 is essentially opaque to IR radiation. A good analgy is to consider visible light and a glass of water. You can see through the glass of water just fine because water is largely transparent to visible light (just like air to IR). However if you put one drop of a dye in your glass of water (about 0.03%) all of a sudden you can't see through the glass of water anymore. This is exactly the same as in the atmosphere. The more CO2 is added the more opaque it becomes to outgoing IR radiation, and the more IR is trapped at the surface of the earth, and the earth warms.
Really? Maybe you can show this evidence that shows the CO2 levels increased before warming?
Or should I just take your word for it?
Businesses stand to reap the rewards. If your business is selling cigarettes your business will do better if you promote the idea that they are good for you, much like they did early and mid 20th century. If your business is selling green technologies your business will do better if you promote the idea that the earth is warming and we are the cause. It doesn't take a rocket scientist to figure out how to market a product.
I'm not saying that using renewable sources isn't a good idea, but I am saying that this Global Warming push that we hear everywhere is a little to much. In the 60's we were heading into an ice age, in the 90's and 00's we're heading into Global Warming. I don't disagree with the fact that the earth is warming, but I do disagree with the notion that we are the cause. If a Geologist can show us the cooling and warming trends of the Earth, it should be pretty obvious that the Earth would be warming with or without us.
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