Arctic Ice Melts, Climate Change And Algae Blooms In Lake Erie

There seems to be little doubt that the Earth is in a warming trend. Glaciers are disappearing and the Arctic ice is melting. Few can deny that the climate is also changing, that more intense storms occur with greater frequency. Few can really understand why this is so, but it is so.

With the slow warming of the Earth over the last century (for whatever reason) the glaciers have been disappearing and most remarkably Arctic ice has been disappearing. The absence of more and more of the Arctic ice field for significant parts of the year is accompanied with significant solar heating. Ice reflects solar energy whereas open sea water absorbs the radient energy of the sun. As the ice diappears the Earth’s warming begins to accelerate. Minimally this warms the northern hemisphere significantly, more and more each year.

As winter approaches in the northern hemisphere, high pressure systems may build over the increasingly open waters of the Arctic and these may act as steering currents for storms that may appear in Russia, Europe, Scandanavia or in North America. Where the storms go may depend also on changes in the Arctic upper atmospheric jet streams. We neither understand where high pressures will occur or nor how they guide the storms which may be more intense than what we are used to.

Secondly, with the Arctic warming heat from the equator may become more troublesome. The Earth is warmed considerably by the sun and tries to even it heat out by allowing escape to cooler regions, but as the Arctic warms the cooling of the equator becomes more difficult — at least it becomes different. What we can see at least is that the regions nearer the equator stay warmer for longer. In some regions the weather is hotter and drier in others cooler and wetter. High and low pressure systems change as the Earth, in effect, experiments with new cooling mechanisms because of new conditions. Science has created models to try to understand what is happening and how it is happening, but if anyone tries to say that they understand these mechanisms and can predict what is happening, they would have to prove that, and they cannot.

What is certainly true is that we can observe what is happening after the fact. In the northern midwestern region of the country around the Great Lakes we have seen alternating years of more intense storms with much rainfall, which have become more intense in the last 15 years. Intervening years have seen drought in these areas. Since 1960 the numbers of days of heavy precipitation in these areas have increased by about 30 percent.The seasons are changing noticably in later winter or early spring often causing intense rain or snow events. Rain events of 1.2 inches or more are now about twice as frequent as they were 40-50 years ago in the area known as the Lake Erie basin.

Increased rain in these areas can have significant consequences. With a 30-40 percent increase in spring rains increased nutrients from farmlands and animal excrement will wash into rivers and streams that feed Lake Erie. Even best farming practices have been unable to reduce nutrient flow into the Lake Erie, in particular to reduce the flow of phosphorus into the production of significant algae blooms in late spring. These blooms can foul harbors, clog motor on boats, and produce areas with lower oxygen concentrations (dead zones) in which the fish populations may be significantly reduced.

Prior to these more recent climate changes the region had controlled or at least reduced the algae blooms by reducing so-called point sources of phosphorus run off from sewage, dredging and open lake disposal. However, with the increased run off of phorphorus due to climate change the former days of alage bloom control now seem to be at an end. Without a significant and costly effort it is hard to forsee the survival of Lake Erie as a significant economic resource.


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