He called out an arborist, and the arborist clearly explained that there wasn't enough rain anymore to support the number of trees on his land, and that the forest was slowly receding as the older/bigger trees took all the water from the other trees.
It finally dawned on him that a place where trees used to happily live to hundreds of years old could no longer support trees.
Still, he thinks CO2 is a con job cooked up by China and that global warming is divine punishment. But it's a good reminder that a lot of denialists are waiting for a personal, practical reason to care.
Four out of five denialists agree!
Something can said to change from a certain standard even if it wasn't perfectly constant to begin with. For example, if I always kept my house at 65-75 degrees for the past year, and now it's 85 degrees inside, I could certainly say that the temperature in my house recently changed and gotten warmer. That might lead me to check whether my AC's working, rather than say "well I guess the temperature has never really been constant, and 85 is within the range of possible non-constant temperatures, so everything's perfectly normal and nothing has changed."
The problem is not that the earth is warming, it is that it is warming at an artificially increased rate.
We (humanity) have gotten comfortable with the way things are, and a change in that is going to mean that things are going to change for us, and we don't like change. Most of our biggest cities are all close to the coast and will be subject to massive flooding in the next 100 years (if not sooner). Much of those same large population centers are also fairly close to being too hot for general survival (without aggressive AC). Our agriculture is all setup for the temperatures we have now, and the rain patterns we are used to. So we are going to have to change both where we live, and how we grow our food (location and probably strains as well).
Global warming is (almost) definitely not going to destroy all life on earth, but many of the forecasts are in extinction-level for most of the large animals. So life in general will continue, and probably humanity (since we are so good at making environment for ourselves), but the (eventual) changes are going to make the world very different, in ways that we are not going to like.
If I pick up your house and drop it two streets over, that could be accurately described as a "location change" of your house. This is still true despite the fact that your house naturally moves some centimeters per year due to tectonic plates shifting around.
Similarly, when global average temperatures saw long term trends of a fraction of a degree of change per millennium, then suddenly started changing at multiple degrees per century, it's pretty reasonable to call that "climate change" despite the fact that it was not completely constant before.