Night-Shining Clouds Get Glow from Meteor Smoke
A key ingredient in noctilucent clouds appears to be “smoke” from meteors as they burn up.
http://news.discovery.com/space/noctilucent-clouds-meteor-strike-120904.html
This article motivated me to write on a subject I have been thinking on a while now. Global warming is all the rage lately and people go out of there way to demonize anyone who even suggests that the treatment might be worse than the disease, but I would like to point out that there is actually a lot of evidence that human activity has gone a long way toward keeping our planet _cooler_ than it might otherwise have been. Take this for instance:
… Methane, which comes from landfills, natural gas and petroleum systems, agricultural activities and coal mining, has become more abundant in Earth’s atmosphere since the 19th century. Methane has been found to increase the formation of noctilucent clouds.
“When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor,” Russell said. “This extra water vapor is then available to grow ice crystals for NLCs [noctilucent clouds].”
If so, noctilucent clouds could be an indicator for the presence of methane, one of the main greenhouse gases.
Given that these very high clouds reflect light before it has any chance to heat the atmosphere or planet surface, a plausible argument can be made that our pollution is helping to keep the planet cooler. Indeed, I recall reading an article several years ago that the cutbacks in sulfur emissions from power plants (so-called acid rain) had resulted in a rather substantial decrease in high altitude clouds of ice crystals and a consequent increase in solar radiation reaching the planet surface. Similarly the reduction in sulfur in jet fuel has lead to less persistent contrails (contrails, btw, reflect quite a bit of light, something only really appreciated after the grounding of the airlines after 9/11). Interestingly, a different article noted that just like jets produce contrails in the upper atmosphere, container ships actually produce something analogous as they too and fro across the ocean. It is entirely possible that by eliminating human pollution due to fossil fuels we could easily result in a dramatic _increase_ in the rate of global warming (please recall, though, that in the longer run (1,000+ years) we are due to hit another ice age).
This is not meant to condone human’s destruction of our global ecosystem through increases in CO2 (I think humans are doing _way_ worse to our oceans, forests and prairies), just to point out that even small changes enacted at a global scale will have ramifications that we more than likely cannot anticipate, let alone deal with effectively.
If ‘simple’ things like leaking methane can cause extremely high altitude clouds that mask the increased heating of the globe (perhaps due to higher solar output, and yes, potentially man-made increases in CO2), what about more ‘complex’ things like hydrogen? What if we (yes, extremely unlikely) were to provide most of our energy from nuclear? Perhaps the cut back in pollutants might elevate all sorts of secondary problems that have been masking the harm our deforestation and raping of the ocean has caused?
Too bad there is no room for rational debate…
