Imagine in 1000 years when archaeologists try to understand how our civilization worked. The designs for the chips will be long gone, the encryption keys for DVDs lost, the data will have disintegrated anyway, we will become the "unknown" civilization. At least when you look at ancient history their writing is on jars or stone tablets.
Except for that Mount Rushmore thing, all the huge and obvious less artistic things we have done to the earth to improve it for human use (flattening land for roads, digging canals, port dredgings, etc.) and all the weird equipment on the moon which will still be around.
As for the ice age issue, ice ages are very bad but the ice cap doesn't cover the entire globe. http://en.wikipedia.org/wiki/Last_Glacial_Maximum
Anyway, Algore says we are past that now because of our fossil fuel farts.