Trees give so much to the world . They create oxygen and shade . They provide shelter to animals and insects . Trees are also a valuable resource . The wood they provide is used for buildings and other products we humans use and need . Trees are so important that some people have made it their goal to protect them . We (can ) call these people “tree huggers .” Word experts say this term first appeared in the 1900s . It describes people who support the protection of forests and oppose logging – the act of cutting down trees in an area for their wood . Today , the term “tree hugger ” describes a person who is an environmentalist . They want to protect nature and the environment – but not just the trees . Someone who wants to save a rare butterfly species or cut greenhouse gases could also be described as a tree hugger . In earlier times , in fact , it was used as an insult . “Tree hugger ” described someone who was seen as extreme , someone who was overly concerned about protecting trees , animals and other parts of the natural world . Some tree huggers do go to extremes to protect trees . Take , for example , a woman name Julia Lorraine Hill . She is also known as Julia "Butterfly " Hill . She is an American environmental activist . For 738 days from December 10 , 1997 and December 18 , 1999 , Hill lived in tree . But not just any tree . She lived in Luna , a Redwood tree in northern California's Humboldt County . Luna is huge , measuring nearly 61 meters tall and about 12 meters across . The ancient redwood has stood in Humboldt County for more than 1,000 years . But that did not stop the Pacific Lumber Company from wanting to cut it down . So , Hill did what any extreme tree hugger would – she moved in ! Hill lived in the tree for just over two years . As the website explains , Hill's main goal was “to bring international attention to the importance of protecting and restoring natural resources .” So , we can safely call Hill a tree hugger . And I'm sure that she would consider that the highest of compliments .