James Hansen, et al have issued a study titled “Young people’s burden: requirement of negative CO2 emissions. The authors say that unless CO2 reduction begins right away and aggressively the next generation and the one after that will have to spend a $535 trillion to make Earth habitable. This $535 trillion is not the $trillions that the warmers want to spend to bring CO2 emissions to a net zero by 2050 or 2100 (depending on which warmer group is talking). The $535 trillion is for removing atmospheric CO2.
The Hansen et al study says the global temperature will melt glaciers and consequently sea level will rise 6 to 9 meters (approximately 20 to 30 feet). Using models, the study determined a temperature rise due to a rise in atmospheric CO2 and then determined that the glaciers will melt which is the big threat. The authors conclude that the current interglacial period would match the Eemian interglacial period which occurred about 125,000 years ago. That period is believed to have experienced a 6 to 9-meter sea level rise. The chart below, from Wikipedia shows the current interglacial period, the Holocene and the Eemian and other interglacial periods. Note that the scale is more or less logarithmic and not linear.
A tangential observation—this chart shows that the Globe’s temperature has been much hotter than at present. Also, the Pleistocene running from about 1 million years ago to about 20 thousand years ago shows glacial and interglacial periods. The peak temperatures are the time of the interglacial and the rest are the times when some part of Earth was covered by advancing glaciers. Were there SUVs and fossil fuel powered plants putting out CO2 that caused the glaciers to melt?
The problem, according to the study, is even when, or if, human CO2 emissions are no longer happening, the CO2 remains in the atmosphere for a long time and would continue to keep the Globe hot. The CO2 atmospheric lifetime (residence time) according to the warmers is between 35 and 95 years. (There are skeptical studies that show CO2 residence time is about 5 to 6 years.) The study then finds that if the Paris Agreement were actually to happen (!!!), the amount of excessive CO2 in the atmosphere probably could be handled with conventional technologies. If it doesn’t happen, the excess would be much greater and other methods, some not yet known, would have to be employed and the study estimates the cost to be $535 trillion.
To pay for the clean up the Developed Nations would be expected to foot the bill. I wonder if the $535 trillion is in constant dollars? The Study does suggest that another source would be legal settlements against fossil fuel companies such as were used against the tobacco companies.
For me, the most troubling part of the study is that it is based on climate models using climate sensitivity of 3C per doubling of atmospheric CO2. The authors seem to be saying that the climate models are correct. The problem is lag time in the climate system Perhaps I mischaracterize the reason, but hey, I am not a climate scientist.
The predictions just get scarier and scarier. This seems to be the pattern. I suspect that credibility will be strained by this one
I do not think the science of climate change is known well enough to make policy decisions. $535 trillion indeed. Who can possibly say with any certainty, that we can predict how advanced science will be in 100 years.
You can read the entire study by clicking here.