claim: "There are other possible causes for climate change which could be associated with solar activity or related to variations in the temperature of the liquid core of the Earth, which is about 5,400 degrees Celsius.
evidence: Increasing sea temperatures in tropical regions (~1 degree C) the last century have caused major coral bleaching, death, and therefore shrinking coral populations since although they are able to adapt and acclimate, it is uncertain if this evolutionary process will happen quickly enough to prevent major reduction of their numbers.