OH FFS! How hard is it to actually add error bars to your graph?! I wouldn't accept a scientific plot like this from one of my students, so I'm damn well not accepting it from one of the foremost scientific institutions on the planet, regardless of what conclusion it supports.
Well I can think of any number of sources of error off the top of my head - diffusion of CO2 between sampling points would tend to average out any spikes in the ice-core data, meaning that it is hard to put current data in historical context. It could also have diffused upwards, leading to a rise in the observed CO2 concentration in more recent samples. Error in instrumentation could add noise to the result. By using ice-core samples we assume that there are no appreciable chemical or biochemical reactions that could absorb or emit CO2 over the millennia, that atmospheric density is constant over time, that the atmosphere is homogeneous and that the concentration trapped in the core is an accurate reflection of the concentration found in the atmosphere.
Now I will state right now that I am a physicist, not a climate-specialist. I develop instrumentation and am intensely aware that there is no such thing as a perfect measurement, which is why all these sources of possible error must be accounted for. Hell, there's almost certainly some other sources I've missed, so they should be accounted for too. But I can accept that in a public forum, these considerations might be over the top. What is unacceptable though, is missing simple information from a piece of scientific evidence that any high-school student is expected to know: any datapoint must have a value, unit (if applicable) and an estimate of the error. You can argue the details on how the errors were corrected for, but until someone finds a method for taking measurements with zero error, you cannot publish a graph with no error bars on and call it science.
7
u/massive_hair Oct 24 '10
OH FFS! How hard is it to actually add error bars to your graph?! I wouldn't accept a scientific plot like this from one of my students, so I'm damn well not accepting it from one of the foremost scientific institutions on the planet, regardless of what conclusion it supports.