Tuesday, July 17, 2018

Heat, Life & Survival

Wandering outside this morning, it was easy to see the toll that our hot, dry summer has taken on the foliage of our Littleton farm.  While heat and water are essential to life, the balance of these factors is crucial and this season has not been kind to the plants.

Life first evolved in warm, shallow seas and near hot smokers along mid oceanic ridges.  Even today, the vast majority of species are found in the Tropics, where moisture is abundant, placing a check on the air temperature.  In desert regions and semiarid landscapes, the low humidity results in dense air which can reach much higher (and often deadly) temperatures; of course, animals and plants that inhabit deserts have adapted to their environment in a variety of anatomic, physiologic and behavioral ways.  While birds and mammals can generate their own internal heat, the low temperatures in polar regions have also required physical and physiologic adaptations for wild residents (fat insulation, thick fur and dense plumage, to name a few).  We humans, having evolved in the Tropics, were able to colonize hot and cold landscapes due to our large brains; the use of clothing, wells, tents and air conditioning come to mind.

Humans and wildlife now face global warming, a product of fossil fuel consumption, which threatens the survival of many species.  Melting polar ice sheets and mountain glaciers are already stressing regional inhabitants and flooding coastal ecosystems (at all latitudes) as sea levels rise.  In concert, warming ocean waters are killing coral reefs, spawning deadly algal blooms and reducing the supply of plankton, vital to marine food chains.  It is imperative that we humans use our large brains once again to mitigate climate change and protect Earth's ecosystems.