Friday, September 22, 2017

Global Warming: Pliocene Climate at 400ppm CO2

"...imagine the Earth where the sea level is about 16 to 131 feet higher than now. Imagine a planet that is hotter and wetter. Imagine, worldwide, it’s roughly 5.4 to 7.2 degrees Fahrenheit warmer than today. And the North and South poles are even warmer still – as much as 18 degrees Fahrenheit hotter than today.
Welcome to the Pliocene. That was the Earth about three to five million years ago, very different to the Earth we inhabit now. But in at least one respect it was rather similar. This is the last time that carbon dioxide (CO2) levels were as high as they are today.... 400 parts per million (ppm). This is the first time in human history that this milestone has been passed. 
CO2 is the most important man-made greenhouse gas, which means (in a simple sense) that it acts like a blanket trapping heat near the surface of the Earth. It comes from the burning of fossil fuels such as coal, oil and natural gas, as well as deforestation. The level of CO2 in the atmosphere has risen from around 317 ppm in 1958 to 400 ppm today. It’s projected to reach 450 ppm by the year 2040.
To some, crossing the threshold of 400 ppm is a signal that we are now firmly seated in the “Anthropocene,” a human epoch where people are having major and lasting impacts on the planet. Because of the long lifetime of CO2, to others it means we are marching inexorably towards a “point of no return,” into territory that is unknown for the human race."

Understand that, normally, the Milankovitch Cycles of Earth's orbital variations drives Earth's temperature fluctuations with CO2 levels lagging along behind. Currently, however, high  CO2 levels are artificially induced and amplifying the greenhouse effect. Since we are already in an interglacial period, the Pliocene gives us an approximation of what lagging temperatures will likely be, if and when they catch up to CO2 levels.

Note: The CO2 that was released to heat my home when I was a kid during the time of the Korean War is still mostly 'on the loose'. It has helped in the overall build up of CO2 levels. CO2 doesn't get resequestered easily.

Greenland Ice On The Move

"A new NASA study finds that during Greenland's hottest summers on record, 2010 and 2012, the ice in Rink Glacier on the island's west coast didn't just melt faster than usual, it slid through the glacier's interior in a gigantic wave, like a warmed freezer pop sliding out of its plastic casing. The wave persisted for four months, with ice from upstream continuing to move down to replace the missing mass for at least four more months."

"This long pulse of mass loss, called a solitary wave, is a new discovery that may increase the potential for sustained ice loss in Greenland as the climate continues to warm, with implications for the future rate of sea level rise."

New Mode of Ice Loss in Greenland: