pitbull ninja:ecoin,you've been given numerous eyewitness accounts,pictures and websites to keep you reading for months.
But over and over again, it's been shown that what you claim is "chemical spraying" is nothing more than water vapor that happens to condense under certain atmospheric conditions, especially when it is saturated with moisture. You know, with very little cost you can set up a "cloud chamber" to simulate this very phenomenon. It's high school science -- maybe your high school didn't have the funding or the better teachers to teach you this stuff?
I've sent and posted links to sites that definitively, calmly and reasonably take every one of the common "eyewitness observations" and goes about explaining how they occur in plain English, plus you have the testimony of dozens of experienced pilots, atmospheric scientists and the like. Now either they're ALL in on it, or, more likely, what you're claiming is occurring simply isn't happening, and you are misinterpreting what it is you are seeing.
For me, proof is this -- you take a direct sample from the "spray" coming out of the back of one of these planes and have it analyzed. You do an epidemiological analysis of the local population to see if everyone is suddenly coming down with an illness that cannot be explained by any other factor. If you discover something in the spray, and it can be proved to be causing some sort of illness which is ACTUALLY occurring in the local population -- and this is fully documented and your materials / methods are accessible to other researchers so they can duplicate your results, THEN I'll believe you.
If you really want to know what is likely causing it to be colder and cloudier this year? I'll put my bets on climate change. A climate system that has more energy in it from trapped heat causes moisture to evaporate out of the soil, which makes it cloudier but not necessarily wetter. What has been predicted, if runaway climate change occurs (and worst-case scenario, the ocean conveyor currents which "pump" heat around the world stop), is that large parts of the world would become both dry AND cold, in essence like an arctic desert.
The EPA website offers this information: "An increase in average temperature can 1) lengthen the growing season in regions with a relatively cool spring and fall; 2) adversely affect crops in regions where summer heat already limits production; 3) increase soil evaporation rates, and 4) increase the chances of severe droughts." Now haven't we seen a combination of droughts and then sudden, violent storm activity, and uncontrollable wildfires due to extremely dry conditions? It doesn't take a rocket surgeon to see that these are all likely related.
http://www.epa.gov/climatechange/effects/agriculture.html