I see already many have answered on this. Just wanted to give my 2 cent. I did a scool project on this topic in 2013 and found correlation with mass animal deaths world wide. since then ive kept an eye on articles on the subject in Msm.
like this
https://geopolitics.co/2016/10/15/weather-weapons-are-real-they-have-a-treaty-to-regulate-them/
or
China is launching the world's largest weather-control machine, with the ability to modify the weather in an area similar to the size of Alaska.
www.forbes.com
there is also a official nawmc.org
then you have very good documentaries that Nomex referred to. What in the/ why in the world are they spraying
i live very near a Haarp facility and i have noticed and documented with photos the planes laying stripe patterns that stays in the sky for hours since at least 2011-2012. another funny part (imho this is connected) to this is the «Strange sounds from the sky» phenomenon wich i have friends who experienced first hand.
Peace