re: #503 Honorary Yooper

Bzzzt. Solar variation has changed quite significantly over the past 150 years (since serious data collection began). Here’s a graph of solar variation with a lot of other information about solar cycles. Take note of the low spots on the graph of solar activity, Number of Sunspots vs. Year closer to the bottom of the page. Take note of the two major minimums, the Maunder and Dalton Minimums. Also note temperature-wise how we came out of the Little Ice Age around 1850 or so. It does correspond with the Industrial Revolution, but it also corresponds with a major increase in solar activity.

So, Avanti, I have some homework for you. Find out the CO₂ levels in the Medieval Climatic Optimum, and find the cause for the warming. Obviously, it was not SUVs, unless they took those to the Crusades as well.

I’ll do the homework for you:

The earth did not warm during the Medieval Climatic Optimum, but Europe and other area’s did. Core samples and the rest show no world wide `warming during that period.

The National Oceanic and Atmospheric Administration (NOAA) states that the “idea of a global or hemispheric “Medieval Warm Period” that was warmer than today however, has turned out to be incorrect” and that what those “records that do exist show is that there was no multi-century periods when global or hemispheric temperatures were the same or warmer than in the 20th century”.
Indeed, global temperature records taken from ice cores, tree rings, and lake deposits, have shown that, taken globally, the Earth actually averaged slightly cooler (by 0.03 degrees Celsius) during the ‘Medieval Warm Period’ than in the early- and mid-20th century.