Extreme conditions of the atmospheric weather and the drastically changing climatic patterns of the globe has seen the human race and the other inhabitants of this planet experience very catastrophic and painful events that are yet to get to their worst if no action is taken. Mass destruction of property and massive loss of precious lives are the results generated by these weather-related extremes, floods, hurricanes, tornadoes and heat waves, just to mention but a few.
For instance, the infamous Hurricane Katrina did claim over 1000 lives bringing with it great economic losses and of course forcing the congress to spend close to $62.5 billion in rebuilding efforts and inform of relief aid to the affected areas. It is for this reason that this government has vastly invested on the research work targeting to predict future climatic changes globally and also put into place effective prevention measures.
Ice core, which is just but samples picked from accumulated snow and ice after along period of time, re-crystallize, trapping air bubbles with it and this is usually accompanied with vast information concerning the climate conditions of the previous world. It’s worth noting that, the earth’s climate is sensitive enough and changes drastically with time, responding to a variety of events within and without its atmosphere.
For instance, volcanic eruptions or even meteorite impacts may send a lot of particles in the air blocking the sun and thus in effect cooling the globe. Green gas emissions also form a increasingly thickening blanket that trap heat and hence the warming globe. Otherwise, changes in the earth’s inclination angle or orientation the sun’s direction also bring cooling or warming effects as suggested by scientists. It is from the ice sheet that ice cores are actually extracted.(David 2005)
From the evidence provided by Antarctica‘s ice cores and also those from Greenland, the rising levels of atmospheric carbon dioxide, precisely began during the period of mass glaciations. Each year, layers of snow pile up with the lower layers being older than the upper ones. These annual layers ultimately form an ice core after relatively long periods in geologic time.The properties of this sample contain accurate data on climatic record of a specified period making it not only powerful but also a very reliable source in paleoclimate research.
Ice cores do prove annual record of precipitation, volcanic activities, temperature and wind patterns and many more. (Alley 2000) The amount of snow accumulated at a specific time within a particular annual layer is critical since it is the thickness of the layers that are significant in the analysis and interpretation stages. The cores extracted from the same area, for instance, may show slight or major differences which could be an indicator of wind patterns as predicted by the direction of snow drifts. Otherwise, scientists use the composition of the snow in the various annual layers of an ice core to precisely predict the past temperatures.
Research also indicates that colder temperatures within snow are due to light oxygen isotope’s deep concentrations in specific zones. This indeed is the theory applied by researchers on the ice sheet. Since the ice age, it is observed that ice sheet has significantly warmed with the top warming as the global temperatures rise while the inner (bottom) layers get warm as a result heat flow that is from within the earth. The fact the middle layer of an ice sheet remains relatively at the temperatures it formed accurately predicts the ice age temperatures. From modern science, the present temperature is used to precisely forecast its temperature in the past through mathematical calculations premised on valid scientific theories.(Alley 2000)
Ultra-precise thermometers dipped into holes made on ice have detected temperature variations that occurred since the ice age. Ice temperatures near the surface are warm, an accurate indication and match to the atmosphere today progressively, these temperatures drop in the preceding layers until the middle where they warm again as the thermometer goes deeper into the layers. These temperatures measured directly represent an approximated trend which is very helpful to the climatologists who compare this trend to the record obtained from the oxygen isotope.
Atmospheric composition in the past has been analyzed using air bubbles that are trapped in ice cores. Such record trends from ice core has proven that greenhouse gases (Methane and carbon dioxide) level of concentration in our atmosphere are currently higher than any known previous level ever in the past 4000,000 years.
During the formation of snow, in the process of crystallization, several tiny particles in the atmosphere including volcanic ash, are trapped, pollen, smoke and dust are trapped within it. It is from this type of data that scientists derive their argument and compile reliable reports on the environmental conditions traced to the time of formation of that snow. Methane levels found trapped in these samples is an indicator of the earth’s wet lands. Ice cores are also used by scientists to correlate concentration of greenhouse gases in the ‘precious atmosphere’ with the current climatic changes. These measurements have clearly verified the role of carbon dioxide in global warming. (Bradley 1999)