Does Global Warming exist?

If so, how has it been measured, observed, and proven?

As odd as it may sound I no longer see butterfly's where I live. Ive researched the species that come here and they dont have any long-term migrationroutes and lifecycles. 1 Degree might seem small, and so might the fact I nolonger see a butterfly in the midst of spring or summer, in fact it may seem stupid, but it still makes me sad.