Moderated Global Warming Discussion

[Reality Check]

IOr maybe you just aren't considering how this gets averaged over the 30 year period, and it may have started much below 1% then risen to as high as 4% some year and still remain at 1% over the 3 decades in question?

This seems to be the point that you are not getting.
You can average anything over a period and get a number. That does not mean that there is a linear increase in that thing. Try doing this with population!

A linear increase in a quantity means that its rate of increase is constant.

Thus if you plot the rate of increase in the quantity against time then you will get a flat line, i.e. the same rate of increase for any time.

When the rate of increase in CO2 per year is plotted, we see that it starts as ~0.9 ppmv/yr in the 1960s and ends at ~2.1 ppmv/yr by 2010. There are large fluctuations in this so we fit a linear line to this. That linear fit shows that the rate of increase in CO2 has a rate of increase.
Look at the second graph in CO2 shame.

 

[lomiller]

It can be when it's approximate and averaged over 30 years.

No. A 1% per year increase is not a linear trend, end of story.

Now, a linear fit can still be used for things that are not linear, but then you need to show the linear fit is appropriate. You failed to do this. Since CO2 growth is undeniably accelerating we all know you can't actually support your claim, but it's amusing to watch you try and weasel

 

[lomiller]

Nonsense.

hy·po·thet·i·cal - Of, relating to, or based on a hypothesis
You do know what the hypothesis here is right? That people will die from exposure to an extra 0.01 degrees per year due to global warming.

The projections were not based on "the hypothesis that more people would die" it was based on death rate data and weather even frequency. In the future please learn what a hypothesis is and what role it plays because right now you are confusing test results with hypothesis.

 

[tkmikkelsen]

Question to the Enlighten

Against my will I ended up in a discussion about global warming the other night. 2 of my friends disagreed about this and the asked me about my opinion.
Now since global warming doesn't interest me that much I don't keep on the latest science and don't really know much. Anyway one of friends argument was that man made CO2 could not be the main culprit for global warming as the temperature had been cooling from the 1940s and until the mid 1970s and again since the start of the new millennium (or at least it was stagnated).
Since I was not too sure about this claim, I looked it up and according to NASA (http://data.giss.nasa.gov/gistemp/) temperature graph for the past 100 years. It looks like my friend is right about the temperature.
Now my question is rather simple, what is the caused for the cooling trend from ca. 1940 until the mid-70s and then the stagnating trend in the past 10 years or so?
Man made CO2 in all those years have been rising. My guess, without knowing anything about it, is that is have something to do with the sun.

P.S.: I am sure the answer that I am looking for is buried somewhere in this thread but I am really too lazy to read through 52 pages of posts to find it.

 

[Malerin]

More on the impact

Seas Could Rise Up to 1.6 meters by 2100

Quickening climate change in the Arctic including a thaw of Greenland's ice could raise world sea levels by up to 1.6 meters by 2100, an international report showed on Tuesday.:

By Alister Doyle, Environment Correspondent

OSLO (Reuters) - Quickening climate change in the Arctic including a thaw of Greenland's ice could raise world sea levels by up to 1.6 meters by 2100, an international report showed on Tuesday.
Such a rise -- above most past scientific estimates -- would add to threats to coasts from Bangladesh to Florida, low-lying Pacific islands and cities from London to Shanghai. It would also, for instance, raise costs of building tsunami barriers in Japan.

"The past six years (until 2010) have been the warmest period ever recorded in the Arctic," according to the Oslo-based Arctic Monitoring and Assessment Programme (AMAP), which is backed by the eight-nation Arctic Council.

more
http://www.scientificamerican.com/article.cfm?id=seas-could-rise-up-to-16-meter

I live at around 4,000 feet, so it will take awhile for rising sea levels to inundate me. But what about those that live near the coats? What can they possibly do in the next 90 years to escape the coming five foot disaster??? Will no one will help these not-so-soon to be imperiled low landers?

Walking Man is here.

http://us.cdn4.123rf.com/168nwm/fuz...-business-man-walking-on-white-background.jpg

Edited by Cuddles: 

Hotlink removed.

That's it...easy does it... a few more steps...There! Now you're safe for the next eighty years.

 

[Trakar]

Scenarios with MIT integrated global systems model: significant global warming regardless of different approaches
http://www.springerlink.com/content/5025626rp532v857/

Abstract
A wide variety of scenarios for future development have played significant roles in climate policy discussions. This paper presents projections of greenhouse gas (GHG) concentrations, sea level rise due to thermal expansion and glacial melt, oceanic acidity, and global mean temperature increases computed with the MIT Integrated Global Systems Model (IGSM) using scenarios for twenty-first century emissions developed by three different groups: intergovernmental (represented by the Intergovernmental Panel on Climate Change), government (represented by the U.S. government Climate Change Science Program) and industry (represented by Royal Dutch Shell plc). In all these scenarios the climate system undergoes substantial changes. By 2100, the CO2 concentration ranges from 470 to 1020 ppm compared to a 2000 level of 365 ppm, the CO2-equivalent concentration of all greenhouse gases ranges from 550 to 1780 ppm in comparison to a 2000 level of 415 ppm, oceanic acidity changes from a current pH of around 8 to a range from 7.63 to 7.91, in comparison to a pH change from a preindustrial level by 0.1 unit. The global mean temperature increases by 1.8 to 7.0°C relative to 2000. Such increases will require considerable adaptation of many human systems and will leave some aspects of the earth’s environment irreversibly changed. Thus, the remarkable aspect of these different approaches to scenario development is not the differences in detail and philosophy but rather the similar picture they paint of a world at risk from climate change even if there is substantial effort to reduce emissions.

 

[Trakar]

Geologic constraints on earth system sensitivity to CO2 during the Cretaceous and early Paleogene - http://www.earth-syst-dynam-discuss.net/2/211/2011/esdd-2-211-2011-print.pdf

...Discussion
Our analyses indicate that ESS was at least 3 C for much of the Cretaceous and
early Paleogene. We stress that this 3 C value is not a mean “best-fit” estimate, but
rather a likely minimum because most ESS estimates exceed 3 C and because our
20 methodology is designed to establish a minimum baseline. How do these minimum
ESS estimates compare to Charney sensitivity? In the present-day climate system,
IPCC (2007) considers <1.5 C very unlikely (<10% probability) and the most likely
range (with 66% confidence) between 2.0–4.5 C (see also Fig. 2). However, a comparison to Charney sensitivity for the ancient past is more appropriate than for the
25 present-day. Critically, GCMs for the Cretaceous and early Eocene simulate a mean
Charney sensitivity of 2.0–2.8 C (Barron et al., 1993; Sloan and Rea, 1995; Shellitoet al., 2003, 2009). If we collapse time in our individual ESS estimates (Fig. 1d), the
resultant probability distribution indicates a mean of 4.9 C (Fig. 2)...

 

[Furcifer]

No. A 1% per year increase is not a linear trend, end of story.

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You can't refute the math.

 

[Furcifer]

The projections were not based on "the hypothesis that more people would die" it was based on death rate data and weather even frequency. In the future please learn what a hypothesis is and what role it plays because right now you are confusing test results with hypothesis.

lol, the "death rate" isn't a test result it's a hypothesis.

 

[Mikemcc]

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You can't refute the math.

We can refute your assumption that it's linear though, it's not. It's accelerating.

Analysis of the observed results by Tamino taken from this article. The rate of increase has approximately doubled since 1960.

 

[lomiller]

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You were asked to justify your approximation on the real data, not some hypothetical data you invented. In your hypothetical scenario yes you may be justified in using a linear approximation, but the real data doesn’t take that form.

Also note that in your hypothetical scenario you would not be justified in saying it’s a 1% per year increase if you were using that linear approximation. This is why I asked you which you were claiming linear or 1% per year.

 

[Trakar]

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You can't refute the math.

In addition to previously demonstrated weaknesses in basic science, there is now an apparent demonstrated deficiency in education and understandings of rudimentary pre-algebra mathematics as well, and that's okay, the majority of people on the planet have relatively weak science and math skills or learning.

Perhaps a basic "Linear and Nonlinear Functions" (http://www.glencoe.com/sec/math/prealg/prealg05/study_guide/pdfs/prealg_pssg_G112.pdf) will help you over the hump?

Of course, the first step is use real figures rather than crude approximations in what some might consider an apparent gambit to obscure the nature of the equations.

 

[Reality Check]

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You can't refute the math.

Yes it is easy to show that a linear increase is a linear increase using dummy data that is designed to have a linear increase!
The math cannot be refuted. Pity it has nothing to do with the actual data.

I see that you understand that a linear increase has a constant rate of increase (e.g. 1%).
Do you understand that the actual data has a increase in the rate of increase increase in the rate of increase, i.e. is not linear?

Using your example
If the ppm is 200 and it goes up to 202, then 206 then 214, it's a increase of 1% then ~1.98% then ~3.88%. This is not a linear increase (and has nothing to do with the actual data).
You can't refute the math.

 

[CapelDodger]

This isn't that hard.

Too hard for you, apparently.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

When did "approximately" come into this?

You can't refute the math.

You can obfuscate, and duck and dive, but you can't refute what you've posted on this thread, nor conceal how long it took you to realise you needed to smuggle an "approximately" in there. (Did my "compound" hint help in that? That would be so gratifying.)

You clearly don't have the instincts of anyone who's studied maths or science or you wouldn't include "linear" and a percentage in the same short sentence. Not without an "approximately", anyway.

Behind this, of course, lies the fallacy of small numbers, what with 1% being a small number (unless added to taxes, obviously) and hence inonsequential. It's a common human failing to fall for that fallacy. Like CO₂ being a trace-gas, which will never grow old.

 

[bit_pattern]

Against my will I ended up in a discussion about global warming the other night. 2 of my friends disagreed about this and the asked me about my opinion.
Now since global warming doesn't interest me that much I don't keep on the latest science and don't really know much. Anyway one of friends argument was that man made CO2 could not be the main culprit for global warming as the temperature had been cooling from the 1940s and until the mid 1970s and again since the start of the new millennium (or at least it was stagnated).
Since I was not too sure about this claim, I looked it up and according to NASA (http://data.giss.nasa.gov/gistemp/) temperature graph for the past 100 years. It looks like my friend is right about the temperature.
Now my question is rather simple, what is the caused for the cooling trend from ca. 1940 until the mid-70s and then the stagnating trend in the past 10 years or so?
Man made CO2 in all those years have been rising. My guess, without knowing anything about it, is that is have something to do with the sun.

P.S.: I am sure the answer that I am looking for is buried somewhere in this thread but I am really too lazy to read through 52 pages of posts to find it.

Check out Skeptical Science, always good for playing the ol' denier whacking-mole

http://www.skepticalscience.com/global-warming-early-20th-century-advanced.htm

Thompson 2008 ends with an intriguing statement:

"compensation for a different potential source of bias in SST data in the past decade— the transition from ship- to buoy-derived SSTs—might increase the century-long trends by raising recent SSTs as much as 0.1 C, as buoy-derived SSTs are biased cool relative to ship measurements"
http://www.skepticalscience.com/A-new-twist-on-mid-century-cooling.html

 

[Furcifer]

Using your example
If the ppm is 200 and it goes up to 202, then 206 then 214, it's a increase of 1% then ~1.98% then ~3.88%. This is not a linear increase (and has nothing to do with the actual data).
You can't refute the math.

It depends on how you label your axes. In the above example you are increasing at 1.8% per year. In the following year a 5.7% increase to 226 would be linear.
It would also validate some of the alarmism we see in this thread. Luckily however this isn't the case

 

[Furcifer]

We can refute your assumption that it's linear though, it's not. It's accelerating.

Analysis of the observed results by Tamino taken from this article. The rate of increase has approximately doubled since 1960.

Yes, and I agree this is where I was mistaken. I confused a linear rate of increase with a linear increase.

 

[Pixel42]

Now my question is rather simple, what is the caused for the cooling trend from ca. 1940 until the mid-70s and then the stagnating trend in the past 10 years or so?

As no-one else seems to have answered this, I'll have a go.

Firstly, the rise in CO2 is not the only thing that affects global temperatures over a timescale of decades, others include variations in solar radiation, the amount of volcanic activity, and ocean currents. The difference is that these others wax and wane, whilst the warming due to increased CO2 only, er, waxes. So if you look at temperature trends over several decades you will see the underlying warming trend due to CO2 emerging from the noise of the other influences. A single decade is not long enough to reliably observe such a trend, it might so happen that one or two of those other influences are at their peak or at their lowest, thus either exaggerating or masking it. For example in the last 10 years solar activity has been unusually low, and ocean currents have also spent more time in their cooling phases than their warming ones. Even so the last decade was still the warmest on record, so it's not true to say temperatures stagnated.

Having said all that, there was indeed a pause in the rise of average global temperature for several decades after WW2. The biggest contributor to it is believed to be aerosols caused by pollution. See global dimming.

 

[excaza]

This isn't that hard.

If the ppm is 200 and it goes up to 202, then 204 then 206, it's a linear increase of approximately 1%.

You can't refute the math.

Visualized below: The "linear" increase of 1%

whoops.

 

[Reality Check]

It depends on how you label your axes. In the above example you are increasing at 1.8% per year. In the following year a 5.7% increase to 226 would be linear.

No it does not depend on how you label your axis. Read the example I made up:
It's a increase for each year of

• 1% then
• ~1.98% then
• ~3.88%
• and I guess then your 5.7%

The graph would have those increases. The rate of increase is not constant. It changes. Thus the increase is not linear.
This is basic mathematics.

You do not need math to see this for CO2 - all you need is a ruler to see that the slope of the graph increases from the begining to the end. See the previous posts that you are still ignoring.