The real issue has not been if climate is changing or if man has an impact in climate change, but how much, how unusual and how serious is climate change. From the article, "How definite is the attribution to humans? The carbon dioxide curve gives a better match than anything else we’ve tried. Its magnitude is consistent with the calculated greenhouse effect — extra warming from trapped heat radiation. These facts don’t prove causality and they shouldn’t end skepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does.
Yes, there are still reasons to be skeptical.
The BEST project is land surface temperature average. The world is about 30% land and 70% ocean. The term, "Global Warming" was once used instead of "Climate Change" possibly because the Globe is not Warming as much as the Land is warming. Then the Oceans never have. The plot above is the reconstruction of Lake Tanganyika temperatures of the past 60,000 years by Tierney et al. The Green is the full temperature reconstruction with the mean value line also in green which on the left scale appears to be close to 23.4C degrees. The Blue is what I think is the normal lower range which has a mean of about 22.7C degrees and the Red is the higher normal range with a mean of about 24.6C degrees. So for the past 60,000 years the temperature range as determined
So you can see the Tasmania part better, here is just the past 12,000 years. It is hard to see but I have the average of the Tasmania lined up with the higher normal of the Lake Tanganyika. The Yellow is a 150 year moving average of the Tasmania reconstruction. The longer the period I average the less variation there is in the data. Notice how the red plot has large spikes that settle down to around average. While it is not as obvious in the Tasmania plots, you can see that it is also coasting into the same average. Both are strangely attracted to that average for some odd reason.
This plot has a number of reconstructions available on the NCDC NOAA Paleo site. In this one the light blue is the Tasmania, the yellow is the Southern South America temperature reconstruction by Neukon Et al, the green is the Taymir Peninsular by Jacoby, the red this time is Greenland by Kobashi et al and the little burgundy series at the far right is the Sea surface temperature from the Hadley Center in the UK. According to this plot, right now we are a little above average.
Looking at those reconstruction, the global climate changes, it changes more on land and it appears to change the most near the poles if the Kobashi Greenland temperature reconstruction is to be believed. Without a doubt, climate does change, but is the "Globe Warming"?
If you live in the higher northern latitudes, damn right it is warming. You have industry and agriculture to thank or blame for that. If there is a fix to that "Global Warming" that fix would be less warmth in the Northern high latitudes where the majority of the "Climate Change" has taken place.
The title of this post is "Strangely Attractive". That is because the Earth's climate system is strangely attracted to two "normal" climate "averages". The high normal where we are now and the low normal where the glaciers grew on land. There is a much larger range of "Global" temperature near the areas that the glaciers like to grow than there is near the liquid oceans. Man, being the industrious devils we are, tend to take advantage of the retreating glaciers to expand territory. That expansion is a part of what is called land use change. That is one of the main causes of "Global Warming". We are strangely attracted to expanding our territory and the Earth is strangely attracted to a range of temperatures. There is a lot more to Greenhouse Gas Theory than CO2, though it is a strangely attractive theory.