What a difference four degrees makes.
That's the difference in latitude between my office in Palo Alto, Calif. (37.4 degrees, just south of San Francisco) and my current vacation spot in Carlsbad, Calif. (33.1 degrees, just north of San Diego).
Up north, we can't grow Jacaranda mimosifolia very successfully due to our typically frosty and occasionally freezing winters. Down here, the tree's vibrant lavender blooms are pretty much ubiquitous this time of year.
Up north, our soil is heavily influenced by at least four local ancient volcanoes — mounts Diablo, Hamilton, Tamalpais and Sonoma — with a resultant fertility that made today's Silicon Valley the original "Valley of Heart's Delight." Down here, with the nearest volcanoes some 4–5 hours away, the local soils are much more estuarine, sandy and lacking the minerals and clays that nourish "exotic" plants.
Up north, Palo Alto averages about 15" of rain annually, contributing to a mostly foothill woodland native plant habitat bordering on evergreen forest. Down here, Carlsbad averages about 7" of rain annually, creating a predominantly coastal sage scrub community.
Up north, our average summertime high temperature is above 78° Fahrenheit. Down here, the average summertime high temp is just under 74°F. However, thanks to the famous San Francisco fog, at night we can drop 22°F — while closer to the equator, Carlsbad drops only 10°F.
Obviously there are pros and cons to each latitude, but you can see how just a few degrees of separation can significantly affect environments and lifestyles. Where would you rather live? And if prognostications of global warming expanding the equatorial zones are correct, and Palo Alto comes to resemble Carlsbad and Carlsbad comes to resemble Puerto Lobos, how would your lifestyle change?