Not exactly. The effects can sometimes be witnessed, but we must be careful in applying climate to what we find in archaeology. Archaeologists have done that in the past, and have found their theories severely questioned since then. For example, a drought that affected Thera at one point in I think the 6th century was taken as one theory as to why the material evidence of Krete was so sparse. Indeed, this climate condition is one that history tells us of (it is mentioned in Herodotos.) But on closer examination, the material conditions on Krete last a century... in no way could the drought have been solely, or even mostly, responsible. Likewise it's been said that climactic conditions were responsible for the fall of the Minoan civilization. This, too, does not exactly fit together. In fact, it is often that climactic conditions having an effect upon the material evidence is perceived when it simply does not exist. We should be careful in applying it as such, because it is a very hard thing to extrapolate from archaeological evidence.
Yes, archaeologists can see the effects. Bones of animals in one layer that don't exist in more recent times, extinctions, food pattern changes, behavioral changes, all can relate to climate change. As for more direct means, a thorough excavation and research process will sometimes have a geologist present, who can make even better determinations of changes via soil layers, etc.
Indeed as you might say, Archaeology is a subfield of Archaeology, but what then differentiates it? Generally it is limted to what I have said, where there is recoreded history, OR a great deal of material history. Thus we don't often speak of an archaeologist digging up things from before 3000BC... that's more the realm of anthropologists, I'd think. Archaeologists deal with the periods in which there is seen to be a bit more in the way of material evidence (and occassionally a period showing a lack thereof.)
To answer, I guess all subfields need to be mentioned, these definitions are in my own words:
Archaeology - The study and recovery of material remains, and the interpretation of those remains.
Cultural Anthropology - Studing culture from around the world, writing ethnographic accounts. Dealing with cultural and methodological theory.
Biological Anthropology - The process of human evolution, looking at changes in bone remains to show evolutionary changes. (A new subfield within this: Forensic anthropology - who deal with skeletal remains of crime scenes, make a profile from bones, looking at bone trauma)
Linguistics - Language (not learning languages, but sounds, meanings, etc)
Applied Anthropology - Applying anthropological concepts to real world situations.
So, on the contrary, I would say that anthropologists are most likely to deal with contemporary cultures (or from historic period lets say) than archaeologists are. I'm not saying archaeologists don't do stuff from 3000BC+, there's actually an excavation in the town I'm at involving a 1690's dutch settlement. But to say they dont deal with earlier is incorrect. If you look at Africa, all these skulls that are being found and placed into the human evolutionary track are being found by archaeologists, and then examined by physical anthropologists, some of these skulls date to a million years ago, maybe more. Paleo-Indian and other prehistoric phases have been found in decent abundance, and are often recovered. Anthropologists deal with theory regarding human culture change over time (hunter to agriculture to industry for example), which involves at looking very far back, but a lot of data they base things like this on are from archaeological finds as well.
However, not only should you say 'the complex part' but also 'the dangerous part' in regards to where there is no historical evidence. Where there isn't any (and even where there is, but it's worse where there isn't) we can get some pretty wild theories which end up being neither provable or disprovable, and end up with no clear picture.
To me that's the good thing about archaeology, I guess you disagree. Reconstructing something from nothing (nothing = historic context), and a pile of old artifacts. Is it difficult? Yes. Do they do a pretty good job regardless? Usually. If you think it is dangerous, then why try examining anything at all?
Just my point, there really wasn't a hole. Basically, the only thing that we didn't know was the extent of the land-mass at the time, thus the extent of that hunter-gatherer culture, Its boundaries have been moved somewhat now, but it tells us nothing more about neolithic human culture, or has not yet, nor do I think it will.
There was/is a hole, because it was recently discovered. Now we know that there was something there. At this point, it might be nothing more than all the other finds in the area. But whether it is or not, it is still worthy of attention.
