In my lifetime I have watched glaciers in Alaska retreat by miles. Check out the video we shot of Mendenhall Glacier in Juneau, Alaska.
I've seen dramatic changes in the breeding of Allen's hummingbirds in my California yard and changes in the migration patterns of native birds that visit. Many of the animals are responding to impacts on native vegetation.
Rainfall in California has declined creating our current drought, but the truth is we haven't had a wet season since 2005. Flood years mixed with low rainfall years are normal for us, but the flood years are disappearing.
Small changes can sneak up on you as you ease into them. But if you are documenting daily events in the natural world, either in data, journal, or photos, the dramatic accumulation of change is undeniable.
I remember when the Mendenhall Glacier covered most of the rocky outcroppings that are now completely exposed. I remember a 300 foot thickness of ice that nearly hid the top of the waterfall that is now completely free to tumble down a barren rock slope. Watch the video and see the beach beside the churning waterfall. I sat on that beach and cried, because when I was a child that beach was completely covered by a wall of glacial ice.