A Few Things Ill Considered

Global Warming Is Nothing New

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.


Objection:

Global Warming has been going on for the last 20,000 years.

Answer:

It is quite true that 20Kyr ago the temperature was some 8 to 10oC colder than it is today, but it is highly arbitrary and dubious to simply draw a line from that point to today and say "Look! 20K years of Global Warming!". If you have look at this nice graph of temperature starting at a point when we were finishing the climb out of deep glaciation, you can clearly see that rapid warming ceased around 10,000 years ago (rapid relative to natural fluctuations, but not compared to the warming today which is an order of magnitude faster). After a final little lift at 8000 years ago, the temperature trended generally downward for the entire period of the Holocene. So the post industrial revolution warming is really the reversal of a many thousand year trend.

A closer view of today’s trend with the context of the last 1000 and 2000 years attached makes it even clearer that today’s trend is striking and opposite to what one might expect without an anthropogenic disturbance.

(Courtesy of Global Warming Art. See source for details on the various reconstructions tangled above.)

If you really wanted to play this "Global warming started X years ago" game you could talk about how we are reversing a five million year cooling trend, or go crazy and track global temperatures right back to the origins of the planet! Not that I can see the point in that…


This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.


“Global Warming Is Nothing New” was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.

Comments

  1. #1 Thirsty
    December 30, 2008

    This link needs to deliver the graph it promises, and this topic needs to be addressed directly. The end of ice-age warmings are an order of magnitude larger than the 20th century warming.

    The ice core data gives your skeptical opponents reason to argue the current warming is (a) de minimus, (b) a natural fluctuation, and (c) part of a longer trend.

    Without the chart you promise, your argument can seem as “highly arbitrary and dubious” as that of your opponents. Further, because you are climate experts, drive-by commenters like myself will tend to expect YOUR side to do a better job at explaining the mechanism that drove the four end of ice-age meltings. (a) Does anyone have any ideas on this, and can those episodes be distinguished from today’s circumstances? (b) After the rapid melting periods, the globe cools gradually. Does anyone have any ideas why this gradual cooling takes place?

  2. #2 coby
    January 3, 2009

    Hi Thirsty,

    Which link is not working for you?

    “The ice core data gives your skeptical opponents reason to argue the current warming is (a) de minimus, (b) a natural fluctuation, and (c) part of a longer trend.”

    As the longer trend (last 8000 yrs) is down, I am not sure I understand your point.

    The ice age cycles were most likely driven by orbital variations (Milankovich cycles), both on the cooling and warming side. These cycles are extremely slow (10′s of thousands of years) and if anything they would be causing a very gradual cooling today.

    Thanks for the comment, I hope I have been helpful to you.

  3. #3 William Pinn
    April 15, 2009

    “A closer view of today’s trend with the context of the last 1000 and 2000 years attached makes it even clearer that today’s trend is striking and opposite to what one might expect without an anthropogenic disturbance.”

    Well one would have to ignore the big picture to conclude that the rapid warming could not happen naturally. Take a look at this 150,000 year chart. Notice how rapidly the temperature increased in the absense of evil humans.

    http://www.ncdc.noaa.gov/paleo/globalwarming/images/petit150.jpg

  4. #4 William Pinn
    April 15, 2009

    “The ice age cycles were most likely driven by orbital variations (Milankovich cycles), both on the cooling and warming side. These cycles are extremely slow (10′s of thousands of years) and if anything they would be causing a very gradual cooling today.”

    The solar cycles seem to fit well with the temperatures of the U.S.–perhaps the biggest GHGs producer:

    http://data.giss.nasa.gov/gistemp/graphs/Fig.D.lrg.gif
    http://en.wikipedia.org/wiki/File:Solar-cycle-data.png

  5. #5 Adam
    April 15, 2009

    William Pinn –

    Well one would have to ignore the big picture to conclude that the rapid warming could not happen naturally. Take a look at this 150,000 year chart. Notice how rapidly the temperature increased in the absense of evil humans.

    I’m not quite sure how you think that graph proves your point. There, we’re talking about rapid warming on the order of several millenia. Granted, on a geological time scale this is pretty fast. For the current warming trend, we’re talking about rapid warming on the order of a couple centuries. In a geological sense, that’s a proverbial blink of an eye. The two aren’t exactly analogous.

    The solar cycles seem to fit well with the temperatures of the U.S.–perhaps the biggest GHGs producer:
    Wow, its hard to even begin to address this statement, as filled as it is with confusion. The term “not even wrong” comes to mind.
    1) You must be seeing something I don’t, because I’m not seeing much correlation between those two graphs.
    2) The relationship between US temperatures and solar irradiance is less significant than the relationship between the solar irradiance and global temperatures (hence the term, global warming). We see here that any correlation stops completely around 1975 or so, and starts to decouple at around 1950.
    http://www.skepticalscience.com/images/tsi_vs_temp.gif
    3) It’s irrelevant that the US is (or was until recently, maybe) the largest greenhouse gas emitter. Emissions that come from the US have the same effect as emissions that come from Kuala Lumpur.

    For your benefit, regarding the solar argument.
    A breakdown of the modeled temperature increase attribution:
    http://en.wikipedia.org/wiki/File:Climate_Change_Attribution.png

  6. #6 Counsel
    March 10, 2010

    The point Thirsty is making is that you show the past 2000 years when we are warming from the “little ice age.” The topic seems to suggest that over the past, say, 1,000,000 years, there has been little difference in temperatures.

    I suggest everyone stop trying to “prove” that man is causing this warming. Who cares? The issue is what to do about it if we want to keep ice at the poles, keep sea level about where it is, etc.

    Why waste all the effort trying to “prove” something when it is the movement going forward that needs discussion?

    When people say to me that the earth, on average, has been warmer than it is now, I agree based on the government’s scientific data/graphs (for instance, PALEOMAP project – http://www.scotese.com/climate.htm). What I say is, “While historic temperatures may have been warmer, continued warming may remove ice from the poles and, due to that, increase sea level rise (through melting ice becoming water) significantly (200 – 375 feet I believe). If we don’t want that sea level rise, why don’t we try to limit human impacts that might be affecting any temperature rise? if we want to protect skiing and snow-boarding, we need to help reduce global warming or we can’t complain when we can’t engage in those activities any more.

    I get much more acceptance from those who “deny” global warming using that rational rather than the “trying to prove they are wrong” approach.

    While the science about what is causing the current warming is very important, I am not sure that the issue of what to do requires a complete history of what to do about it. Did we need to go do exhaustive studies about why the rivers caught on fire before passing the Clean Water Act and regulating human impacts to the water environment? Again, the causes are good to learn, but I don’t think we need to prove the point if we can appeal to their interests and concerns. I am NOT advocating scare tactics–just rationalizing actions based on their interests (skiing, living in the lower-half of Florida, etc.).

  7. #7 Counsel
    March 10, 2010

    The end parenthesis got entwined in the link…

    http://www.scotese.com/climate.htm

    There is the link to the discussion of the PALEOMAP project and data.

    Sorry about the typo…

  8. #8 williampinn
    August 16, 2010

    “I’m not quite sure how you think that graph proves your point.”

    I am not quite sure why you think you have any valid evidence that proves any of your points. Since Earth Day started in 1970, no gloom-and-doom prediction made by your ilk has ever come to pass. A lot of bad stuff was supposed to happen by the year 2000 and never did. You are batting zero and you are asking me how my graph proves my point? LOL! The little red dot at the top right corner of the dot is the drop we contributed to the climate bucket. Get the point, yet? Do you really think humans can stop the climate from changing by removing just one of over 4 million variables (CO2)? LOL! The graph clearly shows we can’t. So if you are really worried about flooding, buy some flood insurance. It is a lot more cost-effective than spending trillions on futile effort to control the climate worldwide.

  9. #9 mandas
    August 16, 2010

    WP

    “….no gloom-and-doom prediction made by your ilk has ever come to pass…”

    Isn’t an ilk a type of deer?

  10. #10 crakar24
    August 16, 2010

    Williampinn,

    “Since Earth Day started in 1970, no gloom-and-doom prediction made by your ilk has ever come to pass”.

    Spot on and we now know the models are crap as they have a warming bias from 200 to 400%. One can imagine all the “end is nigh” studies that need to be toned down a bit now.

  11. #11 Corey Ferguson
    December 10, 2010

    Um your information is wrong. I’m just a dumb “contractor” so obviously my recollection of my education doesn’t count here. But for what its worth. The last three million years we have been in an ice age, marked by heating and cooling cycles between 40K to 100k years. The cycles are characterized by slow cooling resulting in glaciation, then a fast heating trend. Fast heat up and slow cool down. We have been in another fast heating trend since 12k years ago (we started heating at 16k but cooled off for a bit and didn’t come out of our glacial maximum for an other few thousand years).

    So you are dead wrong about us being on a several year cooling trend. But thats just what I remember from my high school physical science class. Again I probably don’t know what I’m talking about and should just believe whatever it is you write up here on your site. And all of you readers should to.

    You know I was coming here go get some straight talk and this is the last post I reviewed and I’m stopping here. I grew up in Alaska and my father fought the big industry media machines for the Dept of Environmental Conservation and led the PR war against Exxon in the spill. Shrewd S.O.B., and the worst thing EVER for winning that war was knee jerk true believer liberals confusing the issues and not letting straight science and fact speak for themselves. This whole site is just another spin job on the science. What do you do that? We need real information not your “pat yourself on the back” arm chair ideas. Our environment is screwed if this is as good as it gets for the cause. This site was supposed to be one of the better ones. Clean it up dude. If you are spinning the facts you are doing industries job for them by fracturing the movement to bits and that is our biggest obstacle in winning this thing.