An effect of global warming?

by Uditha Wijesena

An iguana lies frozen, or possibly just in suspended
animation, on the ground at a Florida Keys
park following a cold snap.

It was only the other day that I saw a news feature on the BBC World Service that USA's Sunshine State, Florida is raining of iguanas. (BBC World Service - News - Raining reptiles why iguanas are falling from Florida's trees). Interested in nature my immediate response was to get the full story. We have heard of raining cats and dogs which is idiomatic English to express the severity of rain and of raining fish which is quite common in the tornado-prone Caribbean Sea and the Gulf of Mexico. Tornados that originate in the sea, suck up seawater and if shoals of small fish are intercepted they too are lifted in the tower to be dropped with the heavy rain that is associated with a tornado.

Raining iguanas was something else. This was said to be the effect of the severe cold that was to be experienced in Florida known as the Sunshine State due to its favorable pleasant weather found year-round.

Inquiries from my kith and kin in Florida confirmed this but they saw no iguanas and it had nothing to do with rain or water at all. In fact, they were the New World Anoles. Anoles are the equivalent of Angamidae (Katussa or garden lizard) in this part of the world. The world is referred to as Old and New in the study of Natural History, and the Americas are termed as the New World.

All Angamidae and Anoles fall into the group of reptiles in the classification of Zoology and are termed cold-blooded animals. This meaning their body temperature is not constant and varies with the surrounding atmospheric temperature. So now the question is interesting. If reptiles are to adjust their body temperature from the surrounding climate, there is no reason for the Anoles to be affected and fall off their tree top abodes. The complication of the matter is as complicated as the discussions of the world leaders trying to intermingle climate change with intended short term economic advantages to their benefit.

Evolution as Charles Darwin said is a slow process of change taking place every day in this world that we live-in and it is so slow that the change taking place within us is very negligible and thereby adaptable. So the reason for adaptability is nothing but slowness.

What if this change was to become instant? Trouble! This is what happened to the Florida Anoles. What most living creatures do with the change in climate to cold weather is to migrate to warmer favorable locations. But there are certain others that cannot migrate for various reasons and they stay back. Evolution has adapted these creatures to hibernate during these periods, which is a very long sleep of around six months with no food or water to which their bodies have got adapted with the regularly occurring weather patterns.

This winter the temperatures in Florida plummeted to around 0c. This is very much below the normal temperature. While cold-blooded Anoles prefer temperatures of around 35c, their blood circulation is affected and become immobile in climates of around 5c. This is not the usual hibernation that we know. In hibernation, the creature is quite aware of it and it finds a nook or an abode safe from predators to hibernate. This was a new experience to which the Anoles were not ready and their bodies simply shut off; thereby they lost their grip on the tree branches and fell to the ground. Many were run over by traffic or were predated by cats etc; most never recovered as the cold temperature prevailed for over 48 hours at times. The lucky ones were collected by the wildlife authorities and were incubated to see another day.

This is just an example of what would happen if the world is to change its climate in a bit of haste to which our bodies could not adapt to in a hurry. The consequences are major, dreadful, and severe. This is only a glimpse of how a group of creatures could vanish from the face of the Earth overnight.

Let's now see the reason behind this unusual drop in the temperatures when there is so much concern on the issue of Global Warming, while temperature monitors report wide scale Global Cooling. Yes, the cooling is no doubt the inverse effect of Global Warming. The planet earth is warming from the North Pole to the South Pole. General temperature is up by 0.8c and even more in the sensitive Polar Regions. The heat is not only melting glaciers and sea ice; it's also shifting precipitation patterns and setting animals on the move.

Ecosystems will change; some species will move farther north or become more successful. Others won't be able to move and could become extinct, like the case with the Anoles.

Only four years ago, it was commonly accepted that the West Antarctic ice sheet was stable, but unexpected melting in the region is causing scientists to re-think this assumption. The entire Antarctic ice sheet holds enough water to raise global sea levels by 62 meters (203 feet).

This melting ice and the increased precipitation in the Amazon discharging large amounts of fresh water into the Caribbean sea has affected the density of seawater to drop, thereby affecting the sea currents also known to act as a conveyor belt, transporting warm surface waters toward the Poles and cold, deep waters toward the Equator. This belt is now said to be broken with the change in the densities of water and the cold water in the Florida Sea penetrated far down to the reef and the effect was devastating this year. The famous Miami Beach was to be strewn with dead reef fish that could not survive the cold currents that sank deeper to the reef.

It would be some time for us in the tropics to realize this change in climate as we do not encounter that much of a temperature variation seasonally. However, the unusually high precipitation and the severe droughts will affect our agriculture which is highly dependent on weather patterns that would change irregularly out of season.

The changes in marine life would be the first to experience the effect of Global Warming; initially with falling temperatures and the change in seawater densities towards the poles which would eventually settle to warmer seas in this water planet of ours, which is named The Earth. 

Published in the Sunday Observer  Spectrum 2010 - 2 - 14

http://www.sundayobserver.lk/2010/02/14/spe21.asp