Atmosphere And Weather

A look at Climate Change over the last Million Years



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"A look at Climate Change over the last Million Years"
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About 56 million years ago during the Paleocene-Eocene Thermal Maximum, (abbreviated as PETM) Earth was bare of ice.   It was due to a sudden and massive release of carbon into the atmosphere.  Scientists cannot know the exact amount, but they calculate that it would be the same amount released today were people to burn through all the Earth’s fossil fuels (coal, oil and natural gas).

Until the excess carbon was reabsorbed and temperatures gradually fell, the earth endured this heated atmosphere for over 150,000 years.  During that test of time, there were floods, insect plagues, drought and extinctions.  Life on Earth proved to be resilient but in the end it had altered in fundamental nature. Today, the earth is experiencing a similar fate due to the consequences of man’s progress.  Today, man is part of the species that are in the midst of this alteration.  To be more exact, scientists are telling the world bluntly that “we are repeating the experiment.”

Heeding the words of the great philosopher, George Santayana, "Those who cannot remember the past are condemned to repeat it", it would be prudent to examine how the excess carbon was released into the atmosphere in the first place during the PETM period.  

The most popular theory is that most was released from deposits of methane hydrate (methane hydrates are ice-like compounds consisting of water molecules which act as a cage around a single molecule of methane). Deposits of these hydrates are found under the Arctic tundra and under the seafloor, on the slopes where the continental shelves link to the deep abyssal plains. 

It is believed that initially volcano eruptions could have instigated a warming of the atmosphere or even minor fluctuations in the Earth’s orbit exposing areas to more sunlight may have melted hydrates allowing methane molecules to escape from their ‘cages’ and seep into the atmosphere.  Methane in the atmosphere raises the earth’s temperature 20 times more per molecule than carbon dioxide.  It oxidizes to carbon dioxide after ten to twenty years and continues warming the atmosphere severely. 

Scientists fear the worst today as the ice caps decrease in size and become thinner.  Methane could be released from the north and the deep sea. 

The facts today:

Fact - today the temperature is the highest it has been in the past two thousand years.   At this pace, the global temperature will, in all probability, rise more than at any other time in the past two million years. 

Fact – it is a unique phenomenon that the rise in atmospheric temperature is global and cannot be attributed to the natural mechanisms that were responsible for prior warm phases.

Fact – the choices made today will directly affect the climate of the future.

Fact – Greenpeace states in its site, “Fossil fuels also account for more than 80% of US global warming pollution. Global warming, if unchecked, threatens to fundamentally change the planet that has sustained our civilization. In the US, people are already seeing some of the effects—wildfires tearing through western states, devastating floods in the Midwest, and historic droughts in the southeast.”

Fact – scientists have been warning of the same exact problems since the late 60s. Luckily, there are solutions.  Renewable energy sources such as solar energy, wind and geothermal do not pollute the atmosphere and are cheaper than fossil fuels (in fact they are capable of providing 96% of the electricity and 98% of the total heating demand in the US).

Greenpeace also points out that these renewable energies could create millions of jobs that will not be allocated to cheaper labor across borders. 

Knowing that there are choices is encouraging.  The facts speak for themselves; it is up to man to make the right choice.  

Quoting Mr. Robert Kunzig (in his article, World Without Ice):

“The PETM merely puts the choice in long perspective. Tens of millions of years from now, whatever becomes of humanity, the whole pattern of life on Earth may be radically different from what it would otherwise have been—simply because of the way we powered our lives for a few centuries.”

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ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://ngm.nationalgeographic.com/2011/10/hothouse-earth/kunzig-text
  • InfoBoxCallToAction ActionArrowhttp://www.greenpeace.org/usa/en/
  • InfoBoxCallToAction ActionArrowhttp://en.wikipedia.org/wiki/Robert_Kunzig