Oceans Rising-Polar Bears Starving

Usually when experts (in this case climatologists) make models of possible catastrophes as time passes we end up with a reality that is a little less dire than the predictions of the model. With the environment there are so many interlocking pieces in the jigsaw that it is really difficult to sort out the end result of the various tweaks we do to the planet every day. It is now becoming evident that our model of global warming is inadequate and reality is turning out to be far worse than the predictions.

Polar Bear Swimming

In the early days of coal mining the miners would take a little cage containing a canary down into the mine with them. If the canary keeled over that signaled there was too much methane and too little oxygen and it was time for humans to get out. We now have a canary and it is the polar bear. With the ocean making up about 70% of the earths surface its temperature and currents are a major factor of our climate and weather patterns. Two important current engines that come to mind are the Gulf Stream in the Atlantic and El Niño in the Pacific. If enough Greenland ice melts and creates too much fresh water then this could shut down the Gulf Stream’s flow.  Without the Gulf Stream New York and London would be very cold cities and small changes in El Niño have major influences on wind and rain for the west coast of North and South America.

With the ocean current engines so vast it’s hard to predict what does what especially when they are influenced by ocean temperature changes measured in fractions of a degree. But there are two very visible features that we can study and measure-sea level and ice. Now glacier ice around the world is important (and it is rapidly disappearing) but the primary ice that concerns ocean levels and temperature are the ice caps of Greenland and Antarctica. Since Arctic ice doesn’t come close to the quantity in the Antarctic it is here that we can see the effects of changes to the oceans much more rapidly. Ice forms much later and disappears far earlier in Arctic regions so that the ice floes that are the playground of ring seals, the primary diet of polar bears, is too far from land for too long a period. Polar bears are either starving or drowning while trying to swim out to the ice. For thousands of years the polar bears’ metabolism has adapted to the extra fat obtained from the ring seals so even if they do find food on land it doesn’t have the quantity of fat that they require. Couple this with the relocation of many native Eskimo tribes because the sea is encroaching on their villages and it doesn’t take a rocket scientist to deduce that the sea is both warming and rising at an alarming rate in the last 20 years. Maybe we should be concerned?

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So how much have the seas raised and what are the causes? The best estimate seems to be a sea level rise of .6 inches per year in the last 60 years. And in the last 10 years it has accelerated to .8 inches per year (and this may still be an underestimate). As water warms it expands and this is known as thermal expansion. Thermal expansion is greater at higher temperatures. So a rise of 1ºC at 5ºC will cause an expansion of one part in 10,000. However, a 1ºC rise at 25ºC (typical water temperature across the tropics) would cause an expansion of three parts in 10,000. It is thought that about one-third of sea level rise in the last 100 years is due to thermal expansion.

Now prepare yourself for the next exciting chapter of global warming and sea level rise-ICE. If all the ice covering Greenland were to melt it would raise the seas by 20-24 feet. If all the ice at Antarctica would melt you’re looking at a rise in sea level of over 250 feet. While it could take 50 to 100 or even 1,000 years for this to happen there are some alarming trends taking place. In addition to Greenland’s rapidly melting southern ice, measurements show that the ice cap in northern Greenland has now started to melt faster which we now have to add into the equation. The next Joker in the Deck is meltwater. As glaciers slowly grind their way to the sea, if they are melting fast enough it appears that this meltwater can seep down through the glacier and act as lubricant. This may triple the glaciers speed into the sea. In the case of the West Antarctic ice shelf which sits on bedrock below sea level, there is concern that the sea could eventually “float” it off.

There are no easy choices but we need to start concentrating on alternative “green energy” and in particular, solar energy. Now I love planes and airports and I don’t see a substitute for jet fuel but we can at least convert land transportation to “green energy” then we could use fossil fuel exclusively for jet fuel and lubricants which would at least slow down this global warming cycle that we have put in motion.