Global Warming as a Detectable Thermodynamic Marker of Earth-like Extrasolar Civilizations: The Colossus Telescope

Advanced civilizations must radiate heat while utilizing planetary energy sources. This waste heat can be a thermodynamic marker of Earth-like civilization. Here we model such planetary radiation and propose a strategy for detecting an alien unintentional thermodynamic electromagnetic biomarker. We show that astronomically observable infrared civilization biomarkers can be detected within an interestingly large cosmic volume using a next generation large telescope. The outcome of such a search will be largely independent of alien communication modes and may have quantifiable statistical completeness as in a true census. Even a null result will help answer the question, ―why do we appear to be alone?‖ The detection of an alien heat signature in itself will demonstrate that civilization can achieve a phase of sustainable global-scale power consumption.