Coming of Age in the Holocene -A Galaxy Insight

Many of us are blissfully unaware that almost the whole of human history -from the hunters and gatherers to the rise of towns and cities, the development of science and medicine -the whole of our great human pageant- has taken place within an atypical period of fair weather.

For most of our 4.5-billion year history, the typical pattern was for the earth to be hot, sans ice anywhere. The current ice epoch started about 40 million years ago, with at least 17 serious glacial episodes in the last 2.5 million years, which coincides with the rise of homo sapiens, the rise of the Himalayas and the formation of the Isthmus of Panama, disrupting the flows of warming currents between the Atlantic and Pacific.

Before 50 million years ago the planet had no cyclical ice ages. What it did have was a pair of glacial whoppers: one about two billion years ago, followed by a billion years of warmth and another mega ice age called the Cryogenian (you get the picture!) when temperatures plunged 80 degrees Fahrenheit, creating a global Antarctica, dubbed by pundits as "Snowball Earth."

Recent analysis of ice cores from Greenland show that climate change occurs abruptly with temperature swings of up to 15 degrees over a 10-year period dramatically altering the climate rather than gradual change over hundreds of thousands of years. One thing is certain, change is on the way.

At last year's American Association for the Advancement of Science Conference in San Francisco, climatologists described an "intensification of droughts, heatwaves, floods, wildfires and severe storms" as "early warning signs of yet more devastating damage to come". In Great Britain, Stephen Hawking and the Government's chief scientist, Professor Sir David King, said that climate change that it posed a greater threat than , in tune with other experts who describe global warming as a "weapon of mass destruction." 

Our period of unusual tranquility known as the Holocene is on the wane. If all our ice sheets melted (and melting they are-in the past 50 years the waters around the West Antarctic ice sheet have warmed 2.5 degrees centigrade) sea levels would rise two hundred feet, drowning the world's coastal cities. Yet another certainty is the complexity of climate change and all its variables from orbit fluctuations known as Milankovitch cycles, to rising carbon dioxide levels, to shifts in tectonic plates, to solar flare cycles. Some believe that global warming might actually trigger the next major ice age.

One thing is certain: it certainly has been nice to come of age in the Holocene. Original posting by Casey Kazan.

See The Andes Vanishing Glaciers

Cosmic Rays may Affect Global Warming

Link

Comments

[Nigel]

The statement "Before 50 million years ago the planet had no cyclical ice ages" is incorrect.

http://andvari.vedur.is/~halldor/HB/205Bol/Lecture7.html

http://www.gsajournals.org/archive/1052-5173/13/7/pdf/i1052-5173-13-7-4.pdf [see figure 1 especially]

[Alice Finkel]

Unfortunately, the Earth's climate appears to be moving into colder territory. Warmer climates such as humans enjoyed in the middle ages and in the Roman times, would be easier to take.

Cold climates bring drought and freezing destruction of crops. Humans starve and freeze in the cold. Most of Russia, China, Canada, the northern US, the Ukraine, and western Europe lose the ability to produce crops.

The US croplands that remain in production will feed the US, Canada, and Europe. Who will feed the helpless third world?

[claudio]

I tend to agree with those that predict in a short while a new litle ice age.
However these little glaciations are generally induced by low or absent SSN of the sun and concurrent tectonic plates movements and will conflict with the heat trapped in the ATM and induced by excess of carbon dioxide we pump up daily on our ATM.

We will see the results of such conflict...presumably soon.

Who of the 2 will prevails ....we do not know.....

Thenafter this little battle we do not have minimum idea of the future climate.

Presumably this is not a problem of us but of the men in the future.

We should be more conscious and prudent about our continuous and heavy pollution of our ATM....

Good luck to all of us including the 'polluters' and regards

[cfmceroz]

The lack of ice age in the past 10K years or so is completely unusual in 50M+ years of earth's history, and is the primary factor in the success of human civilization/overpopulation. This situation is the result of the Geminga supernova event which bombarded earth with radiation and debris. The Stone Age extinction is still going on: we are now in the final phase, whereby one species (humans) overpopulates in a debilitating way

http://cfmceroz.com/blog/2009/05/12/coherent-catastrophism/