A degree by degree explanation of what will happen when the earth warms

[StevieM]

~snip~

Even if greenhouse emissions stopped overnight the concentrations already in the atmosphere would still mean a global rise of between 0.5 and 1C. A shift of a single degree is barely perceptible to human skin, but it’s not human skin we’re talking about. It’s the planet; and an average increase of one degree across its entire surface means huge changes in climatic extremes.

Six thousand years ago, when the world was one degree warmer than it is now, the American agricultural heartland around Nebraska was desert. It suffered a short reprise during the dust- bowl years of the 1930s, when the topsoil blew away and hundreds of thousands of refugees trailed through the dust to an uncertain welcome further west. The effect of one-degree warming, therefore, requires no great feat of imagination.

“The western United States once again could suffer perennial droughts, far worse than the 1930s. Deserts will reappear particularly in Nebraska, but also in eastern Montana, Wyoming and Arizona, northern Texas and Oklahoma. As dust and sandstorms turn day into night across thousands of miles of former prairie, farmsteads, roads and even entire towns will be engulfed by sand.”

What’s bad for America will be worse for poorer countries closer to the equator. It has beencalculated that a one-degree increase would eliminate fresh water from a third of the world’s land surface by 2100. Again we have seen what this means. There was an incident in the summer of 2005: One tributary fell so low that miles of exposed riverbank dried out into sand dunes, with winds whipping up thick sandstorms. As desperate villagers looked out onto baking mud instead of flowing water, the army was drafted in to ferry precious drinking water up the river – by helicopter, since most of the river was too low to be navigable by boat. The river in question was not some small, insignificant trickle in Sussex. It was the Amazon.

http://globalwarming.berrens.nl/globalwarming.htm

[dixiegrrrrl]

1. Wow..I had missed hearing about that.

We are used to, by now, the western rivers going dry in places, which is what the re-newed water wars of California are all about.
I am familiar with those problems, having grown up on the West Coast.

What happens when this countries' famed "salad Bowl" region can't produce enough?

[GliderGuider]

2. Aridity has probably been the single greatest natural threat to civilizations.

About 3900 BC there was a dramatic drying shift in an area that stretched from North Africa through the Middle East and into Asia. the region was named "Saharasia" in a book by the same name by anthropologist James DeMeo. According to DeMeo, that event probably marked the origin of patriarchy, hierarchy and social violence aka organized warfare in today's world. It marked the dividing line between our pastoralist past and what we know as civilization. In a real sense this continent-spanning desert was cradle of civilization, which erupted our of the region in a series of violent migrations throughout Europe and Asia. Columbus and cortez subsequently carried it to a North america that had been largely untouched by the catastrophe, and as a result had not developed the same cultural malignancy.

We should look at the possibility of spreading aridity in the modern world as a loud alarm bell.

http://wrongplanet.net/forums/viewtopic.php?t=146695