Let's not talk about temperature.
Let's talk about Rainfall.
I think I've raised this point elsewhere, but here's what I know - the 12 different climate modeling programs give their most accurate results when you model historical data, when you include a mixture of anthropogenic and non-anthropogenic forcings.
Here's what I want to know, and it's more a point to those that are not (yet) convinced on the AGW issue.
Should local government plan for it? My point is this, AFAIK, they're not just talking about a shift in mean, they're talking about a shift in variance. The predictions are (at least for the part of the country that I'm in) that there will be less over all rainfall, and that that rainfall will come in the form of longer dry spells between 'weather bomb' events.
The point is this - storm water systems are designed around a certain return period (I think it's a 5 year return period for a 24 hour event, not 100% sure on that), however, predictions based on (I think) the average of the 12 models, is that by 2080, what is now a 20 year storm, will become a 5 year storm.
I hope this makes sense, but what I'm getting to is this - Most local governments seem to plan to a 50 year horizon (roughly 2060) so should your local government, as it works through the process of upgrading your stormwater systems, be planning for a 15-20 year even happening on an increasingly regular scale?
Also, this has profound implications for pollution of stormwater - during dry spells, road seal accumulates heavy metals (for example Zinc, Copper, and lead (in those places still using unleaded fuels)), Suspended Solids, PAH's, the list goes on, most of which is washed off the road surface in the first inch of rainfall during any rainstorm. The point here is this, with increasing road surface (as we continue to subdivide, put in more roads, etc), and with, if these models are correct, with dryspells between rainfall events increasing in length, the problem is only going to get worse (The levels of Zinc on most roads are already comparable to Landfill leachate). Then there will be, for example, increased pressure on landfills (the swales on the sides, of in the middle of the roads, designed to help treat stormwater runoff from roads will have to be replaced more often, and currently 'treatment' involves removing them to the 'special contaminated waste' areas of landfills).
IN a similar vein - I notice nobody's discussed this yet.
15th March 2008 - 09:12 PM
Oh, and for the record, if you're going to worry about a star going supernova, η Carinae is the least of your worries (we see it at a significant angle, so most of the energy should in fact miss us). Might I direct your intention instead to Wolf Rayet 104: http://www.usyd.edu.au/news/84.html?newsstoryid=2181