Would climate change be a good measure for SETI searches for intelligent life.
It seems that long after the pyramids of Giza have crumbled and the last remnants of our civilizations are swallowed up by the galcial movements of plate tectonics, our single legacy will be our affect on the climate.
If another intelligent species evolves over time – then traces of this would be the most obvious clue that they had intelligent ancestors.
The time difference between us and animals that we evolved from which had similar intelligence to many long extinct species is 2 million years. This is out of a time period of higher life forms several hundred times longer.
We can see our impact on the climate on a scale of about a million years. Can we measure the climate on a scale of hundreds of millions of years? If so, would a sudden spike be as exciting evidence of non-human intelligent life as a radio signal from space, or are we really so special as to necessarily be the pinnacle of all of our forebears?
BBC NEWS | Science/Nature | Deep ice tells long climate story