As far as I can see, the general trend of the plot is not new knowledge. There are a myriad of this kind of analysis going on in the background all the time, an

As far as I can see, the general trend of the plot is not new knowledge. There are a myriad of this kind of analysis going on in the background all the time, and what is mostly gained is a slightly clearer picture, with more locations covered, better temporal resolution and more independent measurements to crosscheck with (eg so you can be reasonably sure your equipment was calibrated properly, you did a good job taking the samples and applied all the corrections right - of course, don't just believe everything if the results fit, and don't just throw them away if they don't, but at the beginning it is often not clear what is correct, and many teams tackling the problem increases the quality of the results.) The interesting thing here is the measurement method, that can now be let loose on other samples as well. However, that also is one further small step to better data, I reckon, no great breakthrough here. So, it's nice, and the paper will most probably be cited quite a bit within the community, but that should be the level of importance I think. If you want to talk about acid in the atmosphere.. look no further than polluted cities in eg China. It's straight-out unhealthy for people and the acidic rain is bad for plants and things. So it's a problem for forests and agriculture, and also smaller bodies of water and the life within. On the other hand, the aerosols that form block some sunlight and cool the area down, and counteract global warming, especially in the stratosphere (which is only reached by huge volcanic eruptions, we don't have many of there, just a handful per century). (Yes, this is a proposed climate engineering method.) (Btw, the oil sand extraction in Alberta, Canada has produced huge mountains of sulfur. The stuff is only mildly flammable, but I can't help imagine what would happen.) http://www.usmessageboard.com/threads/keystone-xl-pipeline.337712/ http://www.usmessageboard.com/threads/keystone-xl-pipeline.3...