In the beginning of the essay lifeboat ethics what do environmentalist compare to a spaceship

Earth

In the beginning of a formal essay entitled "Lifeboat Ethics", the environmentalist compare the earth to a spaceship. He uses a metaphor calling the earth as the spaceship in his efforts to convince the people to stop destroying instead start taking care of mother earth. 

Claim for social media: social media is a growing issue in our society but, is it really an issue. social media can allow children and young adults to see different aspects of culture, communicate, and share experiences with peers.counterclaim: although social media can be distracting to children and young adults, limiting usuals in social media can ensure social media is an addition and not a control factor to your day to day life.