Global Warming and Climate Change – Part 2


Throughout the geologic record, there are plenty of events with high levels of carbon dioxide. However, the precipitous rise in greenhouse gasses,primarily caused by the unbridled use of petroleum, has created something not seen before: a change so sudden that it threatens to unhinge the very mechanisms by which weather and climate have unfolded for millions of years.

Geologic past

It is known for a fact that the atmosphere of prehistoric earth had very little,if any oxygen. Rocks as old as 3.5 billion years are sliced and analyzed to measure the amount of the gasses found within. It seems that the early atmosphere that brought about life was the result of an atmosphere that was largely carbon dioxide, resulting in a fully water-logged world with oceans that boiled.

Carbon from that distant past was locked away in massive subduction events that literally swallowed sections of the carbon-laden crust. It wasn't until just over 2.6 billion years ago that life evolved on Earth as simple anaerobic organisms, akin to modern cyanobacteria like those seen at Yellowstone's “Paint Pots.” It is thought that the atmosphere of the Saturnian moon, Titan, is at roughly the same stage of development where life evolved here.

Then the atmosphere cooled significantly, some researchers think, from changes in the ratio of methane to carbon dioxide to methane, casting it into the still warm atmosphere as methane dust that “shut down” the early greenhouse atmosphere gone wild. It's thought that after a period of glacial epochs, the Earth then settled down into temperatures generally more hospitable to life with the occasional ice age.

Throughout recorded history since people have been paying attention to the weather, there have been stories about how the climate may or may not be changing.  There is, for instance, evidence to suggest that the biblical flood was based upon a true event that occurred after the last ice age when a massive ice dam burst in Western Asia. More recently, there has been a relatively mild period about 8,600 years ago that is thought to have been caused when an ice dam broke in North America, draining massive Lake Agissiz.

Potential climate change models have been based on the so- called “8.6k year event” that raised sea levels by as much as 4 feet/1.3m while temperatures dropped worldwide by as much as 11C. In this case, gradual increases in carbon dioxide levels resulted in a sudden and dramatic result with global ramifications.

As a result, the Earth stayed cool for hundreds of years before rising carbon dioxide levels caused the temperature to go back up again and restore North Atlantic ocean circulation. It is entirely possible that this event made the first cities on Earth possible.

Since the Industrial Revolution the discovery of how to use the properties of coal to assist with manufacturing was very quickly associated with pollution and ill health. Soot caused crop losses because of reduced solar incidence and interfering with plant growth. As early as the 18th century scientists speculated that hundreds of years of burning coal at the “current” levels might result in a warming of the atmosphere and flooding.

Since about 1750, the concentration of carbon dioxide in that atmosphere has risen from about 270 parts per million (ppm) to nearly 400. This makes concentrations in the late 'aughts higher than they were for over 650,000 years. To make matters worse, the pace at which the concentration of carbon dioxide is accumulating has increased, with an alarming rise in the pace since the late 1990s. It is worth noting that coal usage in the US has continued to rise steadily for electric production into the 'aughts.

Large increases in the use of petroleum came with the advent of the personal automobile, as well as the war usage. Events such as the carbon from burning the oil fields in Kuwait and volcanic activity such as the massive eruption of Mount Pinatubo have also contributed. In normal years, volcanic activity that was once responsible for a very hot primordial Earth, accounts for less than a single percent of the carbon emitted from burning fossil fuels.

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