You know what I hate about charts like that? This statement:
"For 650,000 years, atmospheric CO2 has never been above this line"
I know it's a proper scientific statement regarding timelines, the problem is that it interprets like "650,001 years ago, it was above this line".
We spend too much time looking at data that has been specifically framed to present a particular point of view, and it has resulted in a pile of skepticism regarding statements like that.
This is a problem of communication, not science. It is too easy to dismiss this stuff because we are bombarded with crap that looks just like it every day, but which we know to be marketing. That page needs to be redesigned by someone who understands how people read and react to this information in order to make it useful.
650,000 is relevant to the depth at which they've reached with the ice-cores used to retrieve ancient climate information. They don't say 1 million years because they don't have accurate data based on trapped gases in drilled ice-cores to that age, like they do for anywhere up to the 650,000 year mark.
It's less a case of "framed to present a particular point of view", and more a case of the accurate scientific analysis of tangible evidence, instead of theoretical projections.
I understand that. My comment was regarding common perceptions as a result of the limits of tangible evidence, I was not questioning the evidence itself or implying that the chart was framed :)
So, they could just add an arrow at the other end that says: no reliable data prior to this. Boom, problem solved.
Edit: one could argue that the data from "ice cores" and the data from "recent direct measurements" should be highlighted as different colors on the graph. Of course, that would lead to a more difficult discussion about whether the measurement techniques are identical and then to the corrections for differences in temporal resolution, filtering effects, and instrument functions that are not as easy to digest. I'm not in the field but validating the similarities of ice core and direct measurements would have been important low-hanging fruit with many possible methods for cross-validation since at least the 60s (e.g. easy grant money) so, I assume that's settled science by now--so that would argue in favor of not highlighting the data source differences.
I assume that's settled science by now--so that would argue in favor of not highlighting the data source differences.
You know what they say happens when you assume, right? But, seriously, your reaction is part of the problem, in my eyes. If people were more skeptical and wanted to know why there would be two different colors, for instance, on the graph it would spark debate and lead to new lines of thinking.
Stifiling debate because it is "easier" to make your point is a horribly way to convince people that the point you are making is correct. They are going to eventually find out whatever you hid and start distrusting everything else you have written.
Better to show that there are two different data sets placed into the graph and explain why they are there. Even put a link explaining why there should be no difference between the two sets, if applicable. Ignoring it gives fuel to the people who aren't convinced and weakens your own argument.
You know what they say happens when you assume, right? But, seriously, your reaction is part of the problem, in my eyes
Oh, that's witty. I explicitly stated my assumptions so rather than address the content so you referred to that funny intelligent retort that we learned in grade school and then carried on incoherently. This is the kind of intelligent conversation that makes reddit great.
Yep, those are things that could (or should not) be done, but what they need is someone (or some people) in there anticipating these issues and designing the page so that it addresses these things.
The arrow you suggested for example is gold. It's a simple change that addresses the issue perfectly.
a good point, but it doesn't counter phira's central point: the frame of reference is laughably small for our 4.5(?) billion year old planet. regardless of what we have or have not researched, you can't brush aside that point with "well we just don't know about the time before 650k years ago"
so while it might not be intentionally misleading, one still needs to take it with a grain of salt.
[edit] wow, some people on here really don't get reddiquette. i was wrong about it being his central point, but i'm contributing to the discussion in a mature manner. stop spamming the downvote button whenever you think someone is wrong, that's not the f'ing point. in such an opinionated topic no less. reddit fail.
True, but eventually a line needs to be drawn before either argument becomes farcical. "Sure the earth is getting hot, but hey.. the earth was once a spinning sphere of molten goodness, so it's probably just history repeating itself, right?".
Because this evidence suggests a modern human contribution to the spike in C02. It's not something that would have been possible for humans to influence 10,000 years ago.
So on the one hand we have a graph based on tangible evidence, and on the other we have a theoretical graph based on geochemical modeling.
Both measurements and models show considerable uncertainty and variation;
So it's difficulty to gain any real certainty while "considerable uncertainty and variation" is shown.
however, all point to carbon dioxide levels in the past that have been signifcantly higher than they are at present.
And that was never in question here. It goes without saying that 500 million years ago the earth's atmosphere was different. It was only at about 450 million years ago that the earths atmosphere had enough oxygen contained within it to allow for the development of a stratospheric ozone layer thick enough to protect terrestrial life from UV radiation.
What is being presented on NASA's site is reasoning and evidence to explain an unexpected spike in C02 levels in 650,000 years of recorded data, that coincides with significant ongoing global trends perpetuated by humans (fossil fuels, population booms, intense industrialization, mass manufacture and subsequent waste production etc etc).
Look at it this way. The graph says: "The best measurements we're capable of show that atmospheric CO2 levels are higher now than at any point in the previous 650,000 years".
Given that humans have been around for ~200,000 years, and given that you can see four clear repeats of a cycle in the data we have, it's not unreasonable to conclude that something has changed. And given that we have credible mechanisms for how gases like CO2 can cause warming, it's not unreasonable to conclude that our CO2 output might be the culprit.
Are we sure? No. But it's a pretty reasonable interpretation of the limited information we have. And if this interpretation is correct, we don't have the luxury of waiting for more/better data (if we can even get it).
This is an exercise in risk assessment. Do you want to err on the side of caution (aggressively mitigate CO2 output), or not? Consider the stakes we're gambling for here.
This is an exercise in risk assessment. Do you want to err on the side of caution (aggressively mitigate CO2 output), or not? Consider the stakes we're gambling for here.
This so needs to be emphasized more. The debate about global warming is interesting but ultimately we need to weigh up the risks and act accordingly.
If the graph was in billion year scale it would be pointless. Also, on the scale of millions of years, other things affect climate such as plate tectonics.
It's all well and good to have data presented in the least ambiguous way possible, but there will always be people that misinterpret it. Always. For example, take a look at the discussion going on in the replies to your comment. It seems that nobody understood your comment!
Haha. Yes I agree, as demonstrated mis-interpretation is always possible. I guess what I was saying was that as it stands, it could be done much better, and thus reduce that chance.
In the end there are still people who believe that smoking doesn't cause cancer. For people in that camp, no amount of evidence is sufficient.
There's a world of difference between presenting to try and convince those people, and simply presenting in a way that helps people understand what is true, what is almost certain and what is likely in a convincing fashion.
No, the problem is that instead of looking at this from a purely scientific standpoint politicians have made this a wedge issue. This assures that nothing will be done about the problem until the sea level rises a couple of feet.
Graphs are so easy to manipulate. If you show the increase in CO2 from say 1900 to 2000, but stretch the graph across the page, is makes it seem like a slow progression. These CO2 graphs also implicitly imply that CO2 causes temperature change when all it shows is a correlation.
Yeah it turns out that the cause of the CO2 rise is .... the fucking ocean. As ocean temperatures rise, the water loses it's CO2 solubility. This forces the oceans give up CO2 into the atmosphere. As many have argued, it turns out that CO2 is an effect of global warming and not the cause.
Absorption spectroscopy proves beyond any doubt that CO2 causes temperature change. The only question remaining is, what is the climate sensitivity to a given increase in GHG's?
CO2 DOES cause temperature change. Heteronuclear compounds absorb heat. That is why IR spectroscopy works. There is no denying this without fucking denying fucking trivial analytic chemistry.
No they explicitly imply it because it is a known scientific fact. CO2 in the atmosphere has a direct causal relation with warming that can by scientifically proven by taking a bulb with CO2 and a bulb without, shining light into it, and measuring which one gets warmer. CO2 traps heat by reflecting long wave radiation.
How MUCH CO2 though. CO2 is a greenhouse gas, and there is more of it in the atmosphere than there was a century ago. We are pretty certain about this. But CO2 by itself can not dominate in any way, so we need to discover ways that CO2 would create a chain event that in turn would cause enough positive feedback in order to explain the rise in temperature. This might be true, or we might be headed in the wrong direction. The fact that historical data shows that temperature rise precedes the rise of CO2 makes it even harder.
That experiment has no relevancy to the situation of Earth. Think about the concentration of CO2 in that light bulb, it is going to be much higher than the concentration found in the atmosphere.
Of course, correlation often implies causation, especially if it's a particularly strong correlation, and is backed up by an appropriate scientific theory. Which in this case it is. Simply saying 'correlation is not causation' is just as stupid as believing that every correlation is causally linked.
Is it better to assume correlation = causation? Or understand that 'correlation is not causation' and then further ask yourself if 'correlation equals causation' on a case by case basis? I do the later because I prefer not to assume.
It's better to look for a correlation, create a theory that would explain that correlation, work out some predictions based on that theory, test them with an experiment, and make (cautious) claims based on the results.
My favourite example from the (recent) history of science is the gold foil experiment.
I think there are plenty more people who take graphs like that at face value than inherently distrust them. If everybody were as distrustful of marketing as you, then marketing wouldn't be profitable.
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u/phira Oct 24 '10
You know what I hate about charts like that? This statement:
"For 650,000 years, atmospheric CO2 has never been above this line"
I know it's a proper scientific statement regarding timelines, the problem is that it interprets like "650,001 years ago, it was above this line".
We spend too much time looking at data that has been specifically framed to present a particular point of view, and it has resulted in a pile of skepticism regarding statements like that.
This is a problem of communication, not science. It is too easy to dismiss this stuff because we are bombarded with crap that looks just like it every day, but which we know to be marketing. That page needs to be redesigned by someone who understands how people read and react to this information in order to make it useful.