cojef, volcanoes, cattle, the "burning of fossil fuel" etc., do contribute to the greenhouse effect, however, an asteroid (big S rock on steroids), our moon moving further away from earth, sun going nova and other "stuff" can end planet earth. our planet is over 4 and 1/2B yrs. old and have a life expectancy of another 4 and 1/2B left (about). yes, global warming will continue without us but why escalate our demise? we don't live in a cave anymore, we can think.