Evolution and humans: the last ice age (Evolution)

by David Turell @, Saturday, July 01, 2017, 15:21 (871 days ago) @ David Turell

More on the subject:

https://wattsupwiththat.com/2017/06/30/life-on-earth-was-nearly-doomed-by-too-little-co2/


"The last ice age had intense cold, permanent drought and CO2 starvation – killed most of the plants on Earth. Only a few trees survived, in the mildest climates. Much of the planet’s grass turned to tundra, which is much less nourishing to the herbivores prehistoric humans depended on for food and fur. Recent Cambridge University studies conclude that only about 100,000 humans were left alive worldwide when the current interglacial warming mercifully began.

"The few surviving prey animals had to keep migrating to get enough food. That forced our ancestors to migrate with them, in temperatures that routinely fell to 40 degrees below zero (both Fahrenheit and Celsius). The Neanderthals had been living in relatively warm caves protected from predators by fires at the cave mouths. They had hunted their prey by sneaking through the trees – which no longer existed. They apparently couldn’t adapt, and starved. Cambridge found no evidence of genocidal warfare.

"The most successful human survivors – who provided most of the DNA for modern Europeans – were nomads from the Black Sea region. The Gravettians had never had trees, so they invented mammoth-skin tents, held up by salvaged mammoth ribs. They also developed spear-throwers, to kill the huge beasts from a safe distance.

"Equally important, Gravettians domesticated and bred wolves, to protect their tents from marauders, locate game animals on the broad tundra, and harry the prey into defensive clusters for easier killing. The scarcity of food in that Glacial Maximum intensified the dogs’ appreciation for the bones and bone marrow at the human camps.

"When that Ice Age ended, moreover, CO2 changes didn’t lead the warming. The atmospheric CO2 only began to recover about 800 years after the warming started.

***

"Our crop plants evolved about 400 million years ago, when CO2 in the atmosphere was about 5000 parts per million! Our evergreen trees and shrubs evolved about 360 million years ago, with CO2 levels at about 4,000 ppm. When our deciduous trees evolved about 160 million years ago, the CO2 level was about 2,200 ppm – still five times the current level.

***

"Human numbers, moreover, expanded strongly during the Holocene Optimum, with temperatures 4 degrees C higher than today! Even now, residents of the tropics keep demonstrating that humans can tolerate much higher temperatures than most of us experience. (As we utilize the new malaria vaccine, the tropics will prosper even more.) And far more people die from “too cold” than from “too warm.'”

Comment: Global warming worries are shown to be scientifically stupid:

"Statistician Bjorn Lomborg had already pointed out that the Paris CO2 emission promises would cost $100 trillion dollars that no one has, and make only a 0.05 degree difference in Earth’s 2100 AD temperature. Others say perhaps a 0.2 degree C (0.3 degrees F) difference, and even that would hold only in the highly unlikely event that all parties actually kept their voluntary pledges."


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