"As bad as what humans are doing to the planet is, that really is nothing compared to Earth's natural major extinction events. And yet life still managed to hang on." @rockets4kids
yes what you are claiming is interesting. First I was told that there is no way that humans could affect Earth as a whole - it's too big.
So if you read Professor Andrew Glikson he points out we have already achieved 500 ppm "global gas emissions" (that includes methane and nitrous oxide) - and 500 ppm was when the Miocene era had a 18 C global average - meaning 3 degrees Celsius global average warmer than now. That means we're ALREADY locked into a 3 degree celsius temp increase.
Now the Miocene was about 4 million years ago. OK but we're just going started. The rate of acceleration is what is so bad. OK so after the asteroid hit Earth 65 million years ago then most life went extinct in a few years.
"By analyzing the fish fossils inside, researchers determined that global temperatures were stable for a long time before the asteroid impact, but then, afterwards, temperatures quickly rose and stayed about 5 degrees Celsius warmer for about 100,000 years. MacLeod says it's notable that the impact pumped up carbon dioxide over a short time span that, geologically speaking, is comparable to what humans have been doing in burning fossil fuels since the start of the Industrial Revolution.
"The atmosphere was loaded for a very brief interval of time, and the consequences of that change in atmospheric composition lasted for 100,000 years," MacLeod says. "So it illustrates, I think, really strongly, even if we went back to 1850 levels of carbon dioxide emission, it's going to take a 100,000 years for the carbon dioxide that we've already put in the atmosphere to cycle through the Earth's systems."
So yes modern Western civilization from Platonic math - is very much like the asteroid impact.
"The worst came a little over 250 million years ago — before dinosaurs walked the earth — in an episode called the Permian-Triassic Mass Extinction, or the Great Dying, when 90% of life in the oceans and 70% of life on land vanished. "
"Recently, two groundbreaking studies on the Great Dying reveal that the causes of that mass extinction bear some striking similarities to what's happening today. In fact, in some ways the pace of change, such as the rate of release of greenhouse gases, is much faster today than it was 250 million years ago."
So MORE life as a percentage of total life - was wiped out by the P-T Mass Extinction - and today the rate of destruction is much faster.
"Carbon dioxide in the atmosphere is increasing at a pace 100 times faster than it naturally should. Our planet is warming 10 times faster than it has in 65 million years. Our oceans are acidifying 100 times faster than they have in at least 20 million years, and oxygen dead zones in our oceans have increased tenfold since 1950."
and so 252 million years ago - what happened?
" Over the course of a million years, extensive volcanic activity in what is now Siberia flowed through cracks and crevices of sedimentary rocks, searing oil and gas deposits as it moved along, producing the coronene scientists recently discovered."
"This process gradually released gigantic amounts of heat-trapping carbon gases at levels much higher than today. For comparison, carbon dioxide (CO2) concentrations during that time period are estimated to be a few thousand parts per million (ppm), whereas today, our CO2 level, while higher than it's been in the last 3 million years, is still significantly less, at 415 ppm (but rising fast)."
the key is the RATE of greenhouse gas emissions today.
"And astonishingly, Brand says that the rate of release of heat-trapping greenhouse gases now is much more radical than it was back then. "Right now our emissions are 10 to 20 times higher than what happened at the end of the Permian mass extinction, which was the largest and biggest mass extinction," he said.
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