(Continued from last week)
The Arctic Tern, a unique long distance traveler, undertakes a Trans- world journey from Antarctica to the Arctic to breed in summer.
A much warmer Arctic can pose an ecological threat to this pattern of unnatural journey of long distance travelers.
The cold Labrador Current flowing south from the Arctic bringing lot of planktons, embedded in the floating ice may not be available for the shoals of fish, simply because of the fact that the Labrador Current might cease to flow in near future.
The consequent result may be the loss of a very productive fishing ground, the Grand Banks, of the coast of Newfoundland in North America.
The glaciers retain record of the past climate may serve as a record keeper for glacial activity and climatic changes. Geomorphological studies conducted in the inner Himalayas revealed that the snout of the Gongotri glacier was 50 kilometer downstream from where it is located today at Goumukh.
Without any doubt one of the causes of degeneration of the Himalayan glaciers, except for the winter of 2000-01, were due to phenomenal reduction of winter precipitation, which could be attributed to global warming along with a combination of various meteorological events.
With an abrupt change in the mean global temperature of the earth, the dynamics of the ocean water shall undergo a sea –change. Temperature and salinity status of the ocean shall be altered. All these shall profoundly influence the maritime and coastal weather conditions of many countries. Abrupt warming of the earth’s atmosphere mean a gradual shift of the sub-tropical pressure belts further north, which might disrupt the entire rhythm of winter precipitation pattern of the western margin of the continents.
In the early 1990’s Africa witnessed the worst drought of the century. Nearly one hundred million people suffered from an acute food shortage. This was brought about by extreme weather changes associated with a rise of sea-surface temperature off the coast of north western part of South America.
The phenomenon that had such drastic consequences in Africa is called El Nino, otherwise known as EL Nino Southern Oscillation or ENSO. A recent ENSO event was blamed for an unusual warm weather condition in Alaska, causing an unusual warm winter in western USA, a phenomenal rise in the level of the sea along the coast of California and the death of coral reefs in the Pacific Ocean. Though not new, ENSO events have become more frequent now.
A human induced climate change might throw a number of natural phenomena out of gear, resulting in the disappearance of a number of plant and animal species. A number of gene centers might shift their positions that can have a profound influence in the pattern of production of food grains all over the world. As a result of climates change the tropical forests might be located anywhere between 20-200 kilometers far north. And in the process of spreading over the settlements, mountains, water- bodies etc. the species that will not be able to adjust themselves to the changed environment, shall disappear. Species once become extinct cannot be evolved like a mythical Phoenix. Loss of biotic resources could lead us to a Midsummer nightmare instead of a ‘Midsummer Night’s Dream’.
Remember the Biblical story of Noah’s Ark in the Old Testament, where Noah escaped the flood with his family and animals? If there is any moral to be learnt from that story, it is about conservation against torrid times. (Few years back a group of people claimed to have found the wreckage of Noah’s Ark near Mount Ararat, Turkey).
(Concluded)
(Parag Dutta is former Head of the Department of
Environmental Science, St
Edmund’s College)