Haven't you read all those "studies" which proclaim that surrounding a climate station by asphalt and concrete (I guess we should include AC exhausts as well now), does absolutely nothing to the collected data?
You heard right, not a thing.....cutting down trees, draining all the wetlands, and paving the world doesn't do a single thing to the temperature record. Zilch, nada.
And if you don't agree with that.....well some will label you a GW "denier". Myself, on the other hand, would say you're capable of critical thought. To each his own I guess.
In all seriousness, it can't be considered uncontaminated (I don't know if unreliable is the right term). Those stations are not observing a static system (due to the land use changes), therefore they should not be used to look at temperature trends through the period that the system is being altered.
This is fairly basic science.
