Friday, October 28, 2011

Seasonal Rebirth

A favorite question often asked is, “What is your favorite…?” Many deflect such a query with, “I like them all,” perhaps using the qualifier “for different reasons.” As autumn progresses in northern latitudes there is often trepidation at the approach of winter, sometimes fueled, as in the Midwestern US, by the rumor that a “La Nina” weather pattern is still in effect. Conversely, when late winter moderation clearly signals a weakening of winter’s grip, spirits are lifted.

Cycles are common in our created world. Weather cycles related to temperature and precipitation fluctuations and the consequent sequences of seed time, harvest, and dormancy are topics addressed in scripture. For example, after the Genesis flood, the Lord said, “While the earth remains, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease” (Gen. 8:22 NASB). These contrasting conditions were related in Old Testament times to the annual revolution of the earth around the Sun as it rotates on its tilted axis. These relationships still exist after many thousands of years.

Our revolving earth produces seasonal cycles because of its obliquity: Earth’s axis is tilted 23.5˚ away from the perpendicular to its orbital plane. Without any axial tilt there would be no cyclical seasonal changes anywhere on earth--no annual anticipation of summer’s oncoming warmth or winter’s frigid cold. Seasonal changes result in a refreshing variety of weather in Earth's temperate, middle latitudes. But there is a more important reason to embrace the benefit of these seasonal variations. Grain crops thrive when where warm seed time and harvest contrast with a period of cold dormancy. Humans get about 48% of their calories from grain crops. The Northern hemisphere has 90% of the world’s people and produces most of the world’s grain crops in its temperate zones.

Northern hemisphere winter sun rays must spread over a larger area of land because they arrive at a smaller angle above the horizon. Since they are “shared” by more surface area, any one spot receives less heat. Summer reverses the conditions. The sun takes a shorter path across the heavens in winter. Days are short; heating time is less; cooling time is greater. Again, summer reverses these conditions.

Some people may long for a season-less weather pattern. Without disparaging anyone’s desire for pleasant weather, we must remind ourselves that seasonal changes provide far more interactions between air masses, resulting in distribution and movement of precipitation-producing systems superimposed on the seed-time, harvest, and cold. The Genesis 8 passage seems to affirm the benefits of contrasting conditions--the “ups and downs” of weather. Now and then these ups and downs result in too much or too little rain, or too much or too little wind and humidity for our personal preferences and comfort.

This meteorological variety enables the Earth to support nearly seven billion people. Famines and weather tragedies do occur. But such events are relatively rare and often result from poor human management or deficient stewardship. Heavy media coverage of these tragic events may cause us to see our earth’s weather cycles as cruel rather than as the benevolent gifts of a caring Father.