/sci/ - Science & Math

>>11802101
Because we know there was a much steeper increase in temperature in the 1100-1300 then what shows by reading historical records of agricultural areas:

"From the ninth through the thirteenth centuries, farming spread into northern portions of Russia. In the Far East, Chinese and Japanese farmers migrated north into Manchuria, the Amur Valley and northern Japan."

There is even major population growth associated with the medieval warming period.

"The Vikings took advantage of the climatic amelioration to colonize Greenland, and wine grapes were grown as far north as England, where growing grapes is now not feasible, and about 500 km north of present vineyards in France and Germany. Grapes are presently grown in Germany up to elevations of about 560 m, but from about 1100 AD to 1300 AD., vineyards extended up to 780 m, implying temperatures warmer by about 1.0–1.4°C. Wheat and oats were grown around Trondheim, Norway, suggesting climates about 1°C warmer than present"

Meanwhile climate scientists who spam this crap assume that CO2 levels on ice cores necessarily correlate with temperature. Another method they use to estimate past temperature is through dendroclimatology, which is measuring tree rings, and carries a shitload of limitation like confounding factors, hard collection of medieval trees measurements, diverging problems with actual trees today and so on.

>>11656501
>We haven't really seen any global warming for the past decade
This is is just cherrypicking time intervals.

>Medieval warming period
He uses a graph based on the temperature in one location as if it shows global temperature. Globally, the medieval warm period is barely noticeable compared to current warming. Pic related.

>The last 10000 years
Again he presents a graph showing temperature in one place as if it shows global temperature.

>CO2 is not driving climate, CO2 is not acting as a greenhouse gas
The evidence he presents doesn't support these claims. Showing that interglacial warming was caused by something other than a CO2 increase doesn't show that CO2 can't be a driver of climate at other times. It's also idiotic to say that CO2 was not acting as a greenhouse gas. CO2 always has to act as a greenhouse gas, it doesn't stop being transparent to sunlight and it doesn't stop absorbing and emitting heat just because something else started the warming during an interglacial. And you can't explain interglacial warming without including CO2's contribution.

https://projects.iq.harvard.edu/files/climate/files/shakunetal2012.pdf

>water vapor feedback has never been documented, it's never been seen in the geological record
LOL, since Clark already admits that water vapor is a strong greenhouse gas, all that needs to be documented is that warming increases the amount of water vapor in the atmosphere. This is documented literally every day and nothing in the geological record of the climate can be explained without taking into account this feedback.

Clark's claims get more and more ridiculous and counterfactual throughout the video. I don't see how anyone who fails at basic logic and gets such basic facts wrong can be called a scientist.

>there is no hotspot
There is: https://iopscience.iop.org/article/10.1088/1748-9326/10/5/054007