THE LAST CAST
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JOHN NICKUM
What if There is No Cold water?
The Planet Earth has experienced changes in average temperatures many times in its past history, such as the Little Ice Age, a five century episode starting around 1300; and the Medieval Warming period in the four to five centuries prior to those cold centuries. Is the degradation caused by our present climate change different from these previous events? What can we learn from past history that can help us deal with current problems?
Q
I like this question. We have to learn from history, or we are doomed to repeat the mistakes of the past. I must emphasize that we cannot assume that the future will follow exactly the patterns of the past. There are lessons from the past that may be applicable, but there are also critical differences. The “Industrial Revolution” and the enormous increase in human population are major differences that must be considered as we deal with 21st century climate issues. Maintaining productive and stable fish populations are but one of the challenges facing us as we move into 2022 and beyond. If we are to enjoy angling based on clean waters and healthy trout populations in the coming decades, we must learn from the past and adapt to the future. I have just finished reading a book, The Great Warming, written by Brian Fagan in 2008. The author discusses the effects of substantially warmer climate on ecological, social, cultural, and economic conditions in locations around
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High Country Angler • Winter 2022
our entire planet. The period of time that is the basis for Fagan’s discussions is approximately AD 950 to 1250; although some climatologists expand the warming time to four centuries, AD 900 to 1300. Although most summaries of the Medieval Warming Period focus on the northern hemisphere, especially examining effects in Europe and North America, historical records and evidence derived from such sources as changes in tree growth rings and the mineral composition of coral reefs show that Africa, Asia, Australia, and Oceana were subject to unusual patterns during the Warming Period. Fagan’s studies cover the entire planet except Antarctica and the Arctic. Although temperature increases and their direct effects on human activities are the primary focus of most studies dealing with the medieval warming period, there were other changes that may have had even greater effects on ecosystems, human activities, and human cultures. Severe droughts occurred throughout the world as changes in ocean temperatures produced changes in currents and caused phenomena, such as El Ninos and La Ninas. Century after century, droughts persisted and productive lands were turned into wastelands. Crops failed and starvation caused millions of deaths, both humans and their domesticated animals. Wildlife was also affected, especially “residential” species which lacked the ability to relocate themselves to more favorable conditions. As we evaluate our present warming situation, can we expect the same changes and patterns that developed and persisted in the past? The most probable answer is, “yes, but…” There will be widespread warming, ice caps will melt, sea levels will rise, weather will be more erratic
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