The always effervescent one and I just returned from a memorable trip to Alaska via British Columbia and the Inside Passage. We traveled by plane, train, and automobile, but also by cruise ship, over a period of 19 days seeing many amazing and overwhelming sights. It will require some considerable time and certain discipline to absorb and appreciate all that we experienced, and to recover completely.  Shedding the extra pounds from cruise ship gluttony represents, perhaps, the greatest challenge.

We enjoyed this journey of a lifetime for sure, and we met fascinating naturalists and guides with obvious expertise in so many fields. They told us of human history, they explained changes in the natural environment, and they described the flora and fauna with obvious delight and fascination. These were dedicated professionals and it was a pleasure to hear their stories.

We also enjoyed meeting fellow travelers, although I must admit that Nana is more the gregarious one.  I tend toward more solitary introversion, preferring to indulge in hyper-analysis of experiential minutiae. To illustrate this point, I spent much of my time thinking about what I was hearing and seeing.  I especially tried to comprehend the journey of our planet through time and space. I listened carefully to the explanations of the many experts we encountered, but I also tried to understand their perspectives, as well as their motivations. They were good people, every one of them. I only wished that I could engage with them in more depth, but usually surrounded by dozens of fellow travelers, that was not possible.

As those of you who read my offerings on this website know, I believe that our planet is dynamic, always changing as a result of natural forces and as a result of our civilizing activities. You also realize that I am humbled by what I don’t know, and by what science cannot yet discern. I completely reject the idea that humans are the primary cause of changes in our climate that have occurred in my lifetime. In fact, I believe that we render a potentially dangerous natural world much safer as a result of our efforts.

Without exception, the guides who shared their expertise with us on this journey, assume that humans are the primary and only important cause of dangerous changes on our planet. The important word here is “assume” for they don’t appear to know this from extensive study. I would argue that most have not given it much consideration. They read and absorb the common notions, perpetuated by the media and many political leaders, of a “consensus” that does not truly exist, and even if it did, would be meaningless. History is full of consensus-thinking that was wholly ignorant and unencumbered by the facts. They also suffer from confirmation bias, choosing to focus on observations that seem to confirm their assumptions while ignoring other possibilities, turning a blind-eye to contrary observations.

It is obvious that a majority of the glaciers in Northwest Canada and Alaska are receding while a relative few are advancing. This is not something new. We were handed a brochure illustrating the positions of the glaciers going back to the first records from the Eighteenth Century. We could see the positions of these glaciers in 1750, 1845, 1907, and many other years between and on to the present. It is obvious that the glaciers in this part of the world have been moving back since before the industrial age and before significant contemporary human impact. The present glacial retreat is not accelerating at an unusual rate, and not all glaciers demonstrate the same rates of change. The indigenous peoples who settled in Glacier Bay many hundreds of years ago, for example, experienced both advancing and receding glaciers at rates even greater than seen in modern times.

For context, we must realize that we live in an ice age, named by scientists as the Pleistocene, which is characterized by periods of extensive and perpetual glaciation over the continents. In all of Earth’s history, there have been probably four or five such great ice ages, and each one is unique. The Pleistocene ice age goes back about 2.5 million years. The accepted age of the planet is 4.6 billion years, so the Pleistocene is but a small fraction of the age of the Earth. To understand the expanse of time involved, imagine that the age of the Earth could be described as one year, then the Pleistocene would represent about four hours of that year.

During the Pleistocene there have been numerous periods in which the glaciers advanced, interspersed with time periods known as interglacials during which the Earth’s glaciers generally receded and covered less of the continents. All of these time periods, the ice ages as well as the glacial and interglacial periods, have been shown to relate to changes in the position and motions of the Earth in the solar system and relative to the galactic plane.  Many other factors act on longer time scales such as plate tectonics, changes affecting the positions and extent of continental land masses and oceanic basins.

Human flourishing and the resulting migrations out of Africa track back several hundred thousand years, during interglacials as well as in times of a glacial maxima when mile-thick ice sheets covered most of the continents in the Northern Hemisphere. All of human civilization has come into existence during the current interglacial, known as the Holocene, which scientists mark as beginning about 12,000 years ago.

All through the Holocene, glaciers have generally receded, ice sheets have melted, and sea level has risen by several hundred feet. At the same time, land that had been covered by massive ice sheets continues to undergo isostatic rebound at measurable rates, measured in inches per year in some places like around the Great Lakes in North America. The Holocene has also brought changes in the atmosphere including a steady rise in carbon dioxide.  The rate of change has not accelerated in recent times. Much of this carbon dioxide seems to come from the oceans which have been generally warming for at least 12 thousand years. Remember that the oceans cover more than seventy percent of the surface of our planet. There are active rift zones, 40 thousand miles of them, and hot spots on the ocean floor releasing enormous quantities of carbon dioxide, other gases, and heat into the oceans.

During the Holocene, the Earth has been warmer than present, and other times when it has been relatively cooler. The warmer times include the Minoan, Roman, and Medieval Warm Periods, all of which were warmer than the so-called Modern Warm Period. Since around 1750 to 1800 the Earth has been warming, coming out of the coolest episode of the Holocene, commonly known as the “Little Ice Age”.

All over the Earth, there are hundreds of thousands of glaciers, some advancing, some retreating, but most do both over time. There are many reasons why this happens, and temperature is only one of many causes. Changes in precipitation, amount and type, make a huge difference, and these changes more likely result when prevailing wind patterns shift coupled with quasi-cyclic ocean currents. This is definitely the case in Alaska and this part of the world.

Glacier Bay, College Fiord, and Portage Lake are beautiful places in Alaska filled with ice and water that shaped and will continue to shape the landscape over the coming centuries and millennia. The magnitude of the landscape is incomprehensible. We could see and hear the thunderous calving of the oddly blue glaciers. I separate “see” and “hear” because they reach our eyes and ears at different times. We observed these enormous rivers of ice from a safe distance. I was so in awe of this whole experience, that I snapped over 2,500 digital images trying to capture the incomprehensible.

Toward the end of our journey, on our last excursion, our naturalist guide announced to our group of travelers, as he probably announced to hundreds or even thousands of other similar groups during his career, that Alaska has experienced a seven-degree Fahrenheit increase in temperature over the past 30 years as a result of global warming.  He joked, somewhat seriously, that this was caused by our driving of SUV’s and other vehicles. Ironically, this was on a bus trip to Denali, one of the wildest and least impacted places in the world. At the next scenic stop, I took him aside and showed him the official Alaska temperature record from NOAA which I had saved on my iPhone. He looked somewhat bewildered and muttered something to himself that sounded like, “I’ll have to look into that.”

Yes, he should. You see, over the past century, there is no measurable increase in the average temperature of Alaska as recorded and documented by scientists. There is tremendous variation in temperature and precipitation from year to year.  Surprisingly, the coldest year on record in Alaska was 2012.

Temperature change is not the reason the glaciers are receding in this beautiful place, it is snowing and raining less at this time in history, but this too shall pass. This well-meaning naturalist was just repeating the talking points he had learned from his teachers, who had learned it from others. This is how ignorance is spread, and this is how nations and their leaders go blindly forward like lemmings over a cliff.

Just as my life partner of 40 years and I enjoyed this unique journey, so it is also true that the Earth, our home in this universe, is on a journey of discovery, an ever-changing trip through time and space. It is a wild journey difficult if not impossible for us to understand or even appreciate.

My message is simple, be humble in all that you know. Nothing is more dangerous and threatening to our future than the marriage of ignorance and arrogance.