Local Climate Change

I went to high school in upstate New York. We lived in a house in the midst of what would be considered to be suburban sprawl. The developers cut the forest down and then built roads, infrastructure, and houses. Some small trees were planted here and there, but, for the most part, as we looked at the hill that our house was on we would see the rows of houses and the roads and not really even notice those little trees.

It was seven years between when I graduated from high school and when I went back for a visit. I was astounded that when looking at our hill this time, all I could see were trees. Big trees. The trees' canopy completely obscured all signs of houses and roads.

Orange County, California has an interesting history. In the 1800s, it was primarily scrub brush and grassland and was used for cattle ranching. In the first half of the 1900s, agriculture such as oranges (thus the county's name) became dominant which meant that huge tracts of land were covered with trees. In the second half of last century, the trees were leveled and replaced with suburban sprawl and Disneyland. Of course, some small trees were planted as part of the associated landscaping effort, but it was a superb example of a concrete jungle.

I used to go up to Orange County weekly in the 1980s for some work my company was doing at the time. I hadn't been back (except driving through) since then until we went to Disneyland this week. Once again I was very surprised at how big the trees got. Looking out of our 14th floor hotel room, it looked like a forest in every direction. Sure, there was an occasional big building (or group of buildings) sticking up out of the trees, but it looked remarkably lush and natural. Except, of course, for the minor detail that Orange County is very arid and would not naturally be a forest.

These local makeovers have a major impact on the local climate which will probably dwarf the effects from global climate change for a long time to come. Trees can make the temperature several degrees cooler in the afternoon (6-8°F) and perhaps a tad warmer in the middle of the night. Though I can't confirm it, my experience is that trees make it a bit more humid (which is quite nice in a dry place like San Diego). The air definitely smells different (Orange County was far less smoggy than last time I'd been there). Trees also reduce the wind at the ground level.

The most important thing I've noticed about local environments and climates, is that no matter what happens, the ecosystem always manages to adapt. That's true for volcanic eruptions like Mt St. Helens in 1980 ("[t]he single greatest surprise to scientists entering the blast zone shortly after the eruption was the realization that many organisms survived in, what initially appeared to be, a lifeless landscape"), the area around Chernobyl after the escape of radioactive material ("[s]cientists studying the site from the International Radioecology Laboratory just outside the zone have reported a startling return of many rare species to the area and a general increase in the diversity of many wild plants and animals"), concrete jungles like Orange County and Los Angeles where my brother-in-law now routinely encounters bears in his back yard, upstate New York suburbia where deer are everywhere you look and are a serious driving hazard, and my own backyard in the middle of San Diego where we have possums, skunks, rabbits, foxes, coyotes, and birds, birds, and more birds.

The one thing I've learned during my decades on this planet: life always comes back, no matter what. Climate change, whether local or global, won't stop it.