We humans don’t always like the winter snow for its inconvenience and sometimes safety threat. For many animals, the snow-cover makes winter the best time of year. Scientists who study life in this seasonal microenvironment under the snow call it the subnivium ecosystem. It allows many species of plants and animals to exist that could not survive without snow.
The first scientific writings about the subnivium world were circulated by a lepidopterist (a scientist who studies butterflies) named Vladimir Nabokov. Nabokov was investigating butterflies whose caterpillars eat plants known as blue lupines. These butterflies lay their eggs on the stems of the lupines a few inches above the ground. When snow covers the area, the eggs are protected from the very low temperatures of the mountains where the butterflies live. Scientists conducted a study of those same butterflies in 2019 when there was a significant decrease in the snow cover. They found a 43% decrease in the number of butterflies produced.
This is just one example of life in the subnivium ecosystem. Ruffed grouse burrow into the snow at night and stay in an igloo-like area that can be 50 degrees warmer than the outside air. In wintertime, a surprising number of animals live in the warmer subnivium ecosystem. Wolverines, martens, voles, mice, shrews, red squirrels, and even bears take advantage of heavy snow cover. The protection of snow allows abundant life at high elevations and in polar areas.
Every part of Earth is home to living things because of the design of the animals and plants and the design of water that gives snow thermodynamic properties. It is easy to overlook the statement God made to Job about “the treasures of the snow” (Job 38:22). The simplicity of those words describes a whole world of life in the subnivium ecosystem and the treasure of water stored on snow-covered mountains. The treasure house of snow speaks of the intelligence built into every corner of creation.
In a recent discussion about global warming, a man said to me that we would be better of if we could get rid of all the ice on Earth. I’m sure some of that sentiment came because we were in the midst of an ice storm. We get lots of snow in Michigan, but when the temperature is zero degrees outside, we don’t see freezing rain, just snow. Another member of the discussion pointed out the need for ice so he could do his favorite sport of ice fishing. In truth, the importance of ice is more than just ice-fishing or winter sports.
The design of the water molecule allows us to have ice, and without it, planet Earth would be in serious trouble. The water molecule is polar, meaning that it has a positive end and a negative end. When water freezes, the positive end of one molecule attaches to the negative end of another molecule. If the temperature is low enough, we have a rigid form of water we call ice.
Many people don’t realize the importance of ice. It is a major design feature of Earth and its ecosystems. Ice has a lower density than liquid water, which allows lakes to freeze from the top. That provides winter protection for all the life that lives in water environments. Marine and freshwater life-forms of both animals and plants could not exist if it were not for the design of the water molecule and the formation of ice.
Ice is also a significant controller of the water cycle on Earth. Job 37:6 indicates that snow is a conscious creation of God. Job 38:22 speaks of the “treasures of the snow” which God says He has “reserved against a time of trouble.” People living in the western United States can tell you of the importance of snow and ice, which locks up water in the winter so that it is available during the heat of the summer. If all the ice on planet Earth melted, what would happen to the sea level? There are debates about how much the oceans would rise, but there is no question but that the state of Florida would be submerged.
Ice in the form of snow cleans our air. It provides insulation in very cold places allowing mammals to survive underground during the winter months. We should not underestimate the importance of ice because it is truly a treasure in whatever form it comes. We must do what we can to maintain the water cycle and the balance that God built into the design of planet Earth.
After today, Sunday, December 22, 2019, the hours of daylight will begin to be longer in the Northern Hemisphere where we live. Last night at 11:19 p.m. local time (Eastern Standard), the December solstice occurred as the Sun reached its lowest point in the dome of the sky, even though we couldn’t see it. It happened at the same moment all over the Earth, but, of course, local times varied. (It was at 04:19 Universal Time, and you can figure your local time from that.)
The December solstice ushers in winter in the Northern Hemisphere and summer in the Southern Hemisphere. So for those of us in the north, the days will now start to slowly get longer as the weather gets colder. South of the equator, the situation is just the opposite. At the North Pole, there are 24 hours of darkness when the Sun never appears. At the South Pole, the Sun is up for 24 hours.
Although the December solstice is the time when the Sun is at its farthest point south, it hasn’t moved. We have. Earth’s axis is tilted 23.5 degrees from the path of its orbit path around the Sun. Each year that tilt causes us Earthlings to perceive that the Sun is moving north or south. Earth’s orbit is somewhat elliptical rather than a perfect circle. The point when Earth is closest to the Sun occurs in January during the Northern Hemisphere’s mid-winter. It’s mid-summer in the Southern Hemisphere, so you might think that their summers would be extra hot. Whatever increased heat would occur because of the proximity of the Sun is counteracted by the fact that the Southern Hemisphere is mostly covered by oceans which absorb the heat. That is just another part of our amazingly well-engineered planet.
In Genesis 1:14, we read that God said, “Let there be lights in the expanse of the sky to separate the day from the night, and let them serve as signs to mark seasons and days and years.” Ever since Adam and Eve, people have recognized the Sun’s regular path across the sky and the changes in daylight, sunrise, and sunset times throughout the year. In ancient times, they didn’t understand why. We know why and we marvel at the design.
Every creature on Earth is affected in some way by the length of daylight. Historically, people in the Northern Hemisphere have celebrated the December solstice because it means the days will start getting longer, and spring will return. In ancient Rome, the people called their celebration Saturnalia and honored their pagan god Saturn with immoral behavior. With the coming of Christianity, the Christians re-purposed the holiday to honor the coming of Christ into the world. While the pagans celebrated with debauchery, the Christians made it a time of praising God and the gift of His Son. Jesus was almost certainly not born at this time of year, but more likely in the spring. However, we should take time to honor God for the beautiful design of our planet that makes life possible, and the wonderful gift of Jesus that makes eternal life possible.
Today is the day of the summer solstice in the Northern Hemisphere. It’s the longest day and the beginning of summer north of the Equator and the shortest day and beginning of winter in the southern hemisphere. Today everywhere in the Northern Hemisphere, daylight will be more than 12 hours. In the Southern Hemisphere, daylight will be less than 12 hours.
The reason we have changing seasons of the year is that the Earth is tilted 23.5 degrees in relation to the Sun. As Earth orbits the Sun, the North Pole tilts directly toward the Sun today. At the same time, the South Pole is tilted away from the Sun. In exactly six months, the opposite will be true.
Why is the tilt of the Earth a good thing? If we didn’t have a tilted Earth, less of the planet would be hospitable for life. The area of the Equator would be extremely hot, and the northern and southern regions of the planet would be extremely cold all year. Without the changing seasons, the annual cycle of life would not happen. Life on Earth would not only be much more difficult, but it would also be much less interesting. If the tilt were much greater than 23.5 degrees, the extremes of the seasons would be much more dramatic. All animals and humans would have to migrate to survive.
The tilt of planet Earth is one of many “just right” factors that make our world not just a suitable place for life to exist, but an excellent place for advanced life to thrive. We think that is not an accident but by design. Will we ever find life on any other planet? The chances seem to be slim for any life. The prospect of finding another planet able to support advanced life is next to impossible. If God wanted to, He could create life anywhere. At present, in spite of the best efforts of astronomers to find a comparable planet, there seems to be no place like home.
We have just passed the autumn equinox and what we call “the first day of fall.” It will be late December before fall officially ends at the winter solstice. On the first day of fall here in Michigan, it was unseasonably hot, and people were griping about “where is the cool fall weather we are supposed to have?” Long before the first day of winter on December 20-21, we will have snow. Is there something wrong with the seasons, or is the trouble with our understanding?
“Equinox” suggests that the length of the day is equal to the length of the night. The Sun is overhead at the equator, and from now until December 20 it will be directly overhead at progressively greater southern latitudes until it reaches just past 23 degrees south latitude. Here in the north, the Sun’s elevation above the horizon will get progressively lower, meaning that less and less of the Sun’s energy will strike the Earth’s surface so the weather will get cooler.
The problem with this simple picture is that there is a lag in the seasons. During the summer months in the Northern Hemisphere the lakes and oceans warm from the sunshine. Water has a high specific heat, so that heat is stored and is released slowly. That means we stay warm longer than expected in the fall. In the Southern Hemisphere the picture is complicated by the fact that the Earth is closer to the Sun during their summertime, so the radiation is more intense. That might be a problem except that the Southern Hemisphere has more water than the Northern Hemisphere because oceans cover more of the southern Earth’s surface. With that greater storage and absorption capacity moderates the temperatures in the Southern Hemisphere.