It is quite possible to change microclimates[0], even in a small area, and guess what, you change enough microclimates you change the climate in the whole area.

A great example of transforming large tracts of land is the UVM Jericho research forest in Vermont. It was farmed for nearly 150 years, its soil degraded to the point where it was sandy and barren. I've heard it described as a moonscape. After planting 70,000 trees [1] and letting nature do its thing, it now resembles an old growth forest. It's a prime example of nature's capacity to heal itself and is a source of hope for me in the context of climate change.

0: https://en.wikipedia.org/wiki/Microclimate

1: https://www.uvm.edu/rsenr/jericho_research_forest_and_conser...