There are some observers of climate change who see the whole process as life-and-death. But they do not watch TV, or read blogs, or even listen to lobbyists for one viewpoint or another. They don't do CO2 concentrations, they don't even look at thermometers. These millions of first-hand observers go with what they see and feel and know based on everyday experience. For these observers it's a matter of life and death.
The Brant in the Pacific Ocean no longer find it necessary to migrate south to Mexico.
Many small songbirds now winter much further north than they did forty years ago. The Purple Finch has moved its range over 400 miles northward. Wild Turkeys, Mockingbirds, Cardinals, Pine Siskin--the list of northward moving American birds is a long one.
Whole ecosystems are changing as grass takes advantage of warmer and earlier springs.
Many wildflowers bloom earlier now, insects are on the wing earlier.
In Europe tits are being affected by climate change.
Caribou, Arctic fox, monarch butterflies, alpine animals--all affected by climate change. Marmots find the new weather patterns misleading. Robins migrate north earlier in North America.
Here where I live in southern Oregon a number of birds that were once considered "Californian" are now regular all winter: Black Phoebe, California Towhee, White-tailed Kite, Red-shouldered Hawk, Anna's Hummingbird. I compare what I see now with what oberservers saw here forty years ago. Don't need a computer model for that.