Throughout this tale, the Green Knight represents nature, and when Gawain crosses the Green Knight, he is in fact contending against the environment. The interactions of Gawain and the other knights with the Green Knight exhibit the Arthurian society's mutual fear and respect for the forces of nature.

When Bertilak de Hautdesert takes on the form of the Green Knight, he displays his supernatural power with nature as his medium. When the Green Knight makes his appearance in King Arthur's court, the knights are in awe to see the “verdant green” (161) man with “butterflies and birds embroidered” (166) on his clothes, and a head of hair that “to his horse suited” (180). Although the Green Knight is a human, his appearance is at once vegetative and animalistic, as if he had just emerged from the bushes into the human realm.

He is a mélange of all facets of the natural world, representing many types of flora and fauna all coexisting on a human body. The knights of the Round Table do not know what to make of him, so they both fear and admire him in their confusion. When Gawain hits the Green Knight's neck with the ax, the Green Knight “fell not… nor faltered a whit” (430), then picked up his head and left so easily in a way that was “a wonder past compare” (466). Much like a tree, he is able to lose parts of his body without enduring substantive harm.

This regenerative power is fantastical and even frightening to the human world, but a very unexceptional ability for plant-life. The Green Knight could well be described as an evergreen embodied in human form, and represents the intersection between humanity and the natural world. His ambiguity makes him a dubious visitor to King Arthur's court, causing the knights to be uncertain whether he is friend or foe.

The Green Knight further perturbs the knights by challenging their belief that humans are superior to the rest of the natural world. When he appears in Camelot, he does not arrive unarmed: “In his one hand he had a holly barb… and an ax in his other” (206-208). Traditional pagan belief holds the former as a symbol of life and rebirth, and the latter as a symbol of death. By bringing these he is, in a sense, offering the knights a choice between life and death.

He shows them their mortality, reminding them that it is a natural concept that humans can never gain control over. This is further aggravated by the fact that the symbol for life is a plant, whereas the symbol for death is a man-made weapon, implicating humanity in its own death. Whereas the knights display their power by adorning themselves with “fastenings of the finest gold” (577) and diadems “with diamonds richly set” (617), the Green Knight does so with his bold disposition that causes “a swooning silence in the stately hall” (243) of Camelot.

The Green Knight garners his strength from his natural body and mind instead of depending on material luxuries. When he appears, the knights sense that he is more powerful than they are, so they allow him to take control. They are afraid that, even with their steel weapons and all their man-made accessories, they cannot overcome him. The knights are forced to see that the power of nature is ultimately stronger than their own.

However, Gawain's conflict with the Green Knight shows more than just the negative sentiments toward nature; it shows the society's respect for the intrigue and mystery of nature. By introducing an adversary that derives his power from nature, the poet of Gawain can give this character mystical, superhuman powers that cannot exist in the man made world. The Green Knight is “as lightning quick and light” (199) and has plant-like rejuvenating powers.

The society recognizes that this is something impossible for humans, but it is not outside the capacity of other parts of nature. They respect that nature can so easily achieve something that is completely magical for them. The Green Knight also has “a beard big as a bush” (182) to represent his age, whereas the knights of the Round Table are “but beardless children” (280) and “young bloods” (284).

The Green Knight, as the representation of nature, is old as the earth, and brings with him the wisdom of many epochs of life. Although he mocks the other knights for their youthful nature, it does less to insult them than it does to make them revere his age. In the Arthurian society, it is customary to honor elders, and the age of the earth is just about as old as anyone can be. After Gawain meets the Green Knight to complete their deal, he confesses, “Your cut taught me cowardice, care for my life” (2379).

Gawain's final encounter with the Green Knight is much like an alteration in his state of mind. It allows him to transcend his society's values, and understand his purpose in the world in a different light. The dynamic of the society with the Green Knight shows that they accept, albeit reluctantly, nature's superiority over them in its ability to achieve what they can only imagine.

When it is revealed in the end that the Green Knight is in fact just the mortal Bertilak de Hautdesert, this does not diminish the significance of nature in the story, but in fact enhances its importance. The Green Knight finally admits to his real identity as Bertilak and explains that Morgan le Fay “put this shape upon” (2459) him in order to seek revenge on the queen of the Round Table. His initial intentions with this disguise are certainly far from innocent; however, as the Green Knight, Bertilak no longer attempts to frighten the queen, but instead succeeds in teaching Gawain a valuable lesson.

When Bertilak takes on the powers of the Green Knight, he also takes on his wisdom, and does good deeds where he originally planned on doing harm. After Bertilak is yet again settled as himself and offers for Gawain to “make merry in [his] house” (2468), the spirit of “the knight all green in hue, wheresoever he wished, he went” (2477-2478). This suggests that the Green Knight may in fact be a separate entity that took over Bertilak's body.

If this is the case, this indicates that the embodiment of the Green Knight-or rather, the return to nature-purified Bertilak's initial purpose and caused a moral transformation in him as well. The spirit of the Green Knight leaves Bertilak once his deed there is done. The poet of Gawain corrects sinister intentions by bringing the characters back to the simplicity of nature. This illustrates a broader admiration of the powers of nature even in the part of the poem that seems to diverge from this ideal.

The use of fantastical characters in literature allows authors to present morals and lessons in idealized terms. The character of the Green Knight is an excellent facet for what the poet wishes to demonstrate about the ever-present power of nature in a society that is progressing away from the earth. Their sentiments toward the Green Knight reflect on their sentiments toward nature. The people of the Arthurian society undergo many transformations in which they vacillate between fear and admiration of the natural world. Clearly, this state of indecision has continued long past the time of Gawain.