Scarcity is the motivating force behind action.
Fatigue is the inevitable end-process of any motivated action.
The Sun cannot sustain itself indefinitely...

If Abundance and Energy were the aspects of reality, then no action would occur, because nothing would need anything. — darthbarracuda

This is all true, though we need not concern ourselves with the very far distant demise of the solar system as a life-friendly environment. The planets and sun won't disappear, but they won't be the same. The earth will be a dead planet, the sun will no longer sustain life. We, as a species, will almost certainly have extinguished long before then, along with most of the other extant species. Life began 3.5 billion years ago, life has been continuous since it began, but almost all species have extinguished along the way. We will too--long before life becomes impossible.

You and I think scarcity is reality, but there are some people (oddly enough, certain marxists and certain Trumpences`, who deny that scarcity is a factor in human life. "We can always overcome scarcity one way or another." True hogwash. Theoretically, the earth contains within its mass more than we will ever need, but the second element, Fatigue, has to be taken into consideration. We do not have enough energy to extract everything useful from the mass of the earth, and still live here.

Animals do get weary--I'm getting tired out, for sure--and our human systems fatigue as well. Society fatigues, wears out, get's tired, dull, stupid, and extinguishes. So do ecologies.

Fatigue is the inevitable end-process of any motivated action. — darthbarracuda

Prior to my dying (fatiguing), I have a child. That child is a new bundle of energy. He then fatigues and dies. This cycle does not lead to an eventual end process. It goes on forever if you accept that no energy is every created or destroyed. It just keeps forming and re-forming. It's a fixed cycle. It's not like the sun burns out and that energy is lost forever. The energy just went somewhere else.

What about the 5 Great Extinctions--Ordovician-Silurian extinction occurred about 439 million years ago, then the Late Devonian extinction, the Permian-Triassic extinction, the Triassic extinction, and finally the Cretaceous-Tertiary extinction? Life doesn't always just keep going on, and on and on...

Interestingly, fatigue, as a physiological condition, is a kind of regulative emotion that sets in to protect the body from overexertion: it is a kind of check on corporeal excess that is not a result but a mechanism that aims to sustain oneself (see: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323922/). So to the OP one ought to oppose a Nietzschian vision in which being is not defined by lack, but by excess, abundance and gratuitousness:

"A living organism is not an abyss; it is a dynamo. In being healthy, in being alive, our organisms generate energies in excess of what we need to satisfy our hungers and thirsts. In so much of what we do, awakening because our body is recharged overnight, dancing in the morning sunlight, going for a mountain hike on the weekend, we give without expectation of return. ... To feel healthy is not to have the essentially negative notion of no debility, no sickness that we shape from the doctor’s (or our own, amateur doctor’s) examination but to feel exultant energies to burn. The exclamation “How happy I am!” catches up a surge of exhilaration within, intensifies it, and makes it flare outward.

....The vision in us—I am a dancer! I am an adventurer! I am a revolutionary!—calls forth, intensifies, and consecrates the productive and sacrificial powers in us. The forces mobilized by a vision are not oriented toward pleasure nor the excessive and monstrous excesses of pleasure in pain; they aim at a work or an artwork, a revolution or a transfiguration. We know inwardly that we have kisses and caresses to squander on someone, have a tenderness and an excitement to give someone such as no lover has ever yet given anyone. We have the conviction felt in exhilaration of having the strength and the spirit to train and to inspire our body to dance as no one has ever before danced; we feel inwardly we have the heart and the nerves to endure all the risks, disasters, failures, and savageries of the revolution. The forces mobilized by a vision in an individual may well intensify the Promethean and reptilian strengths to endure the unintelligible and absurd destiny of a body born for or imprisoned in pain. Trapped, caged, straitjacketed, we know a will that shall not bend and the terrible force of our curses." (Alphonso Lingis, "My Own Voice").

ugh, there's a certain type of person who needs others to understand how brimming they are with joie de vivre. The most vibrant prof at the seminar! "Dancing in the morning sunlight" "kisses and caresses to squander on someone." This is Walt Whitman Kitsch with a dash of narcissistic faux-paganism. It's as irritating, in its way, as the jeremiads of a Cioran.

Anyway, how in the dickens does fatigue-as-defense-against-overexertion mean we ought to be exuberant Nietzscheans? What?

Ha, I see where you're coming from but there's a darker side to abundance than 'joie de vivre' which the Lingis quote doesn't quite get across - think here of obsession, wastefulness, libidinal pathology (of the Kantian stripe), envy, jealously, neuroticism, eroticism of the Sadeian kind and so on (all the things Bataille liked to go on about) - the Freudian death drive, properly speaking. It's these features more than anything that the primacy of scarcity can't even begin to capture. To be able to squander kisses is equally to be able to squander time, to be unproductive, to be consumed and haunted by our infatuations. Scarcity simply comes off as paper thin as a motivation when we consider the full range of human behaviour.

The point about fatigue is more that it's simply a weird extrapolation to say something like 'the Sun fatigues'. The Sun has no emotion, it is far more uncaring than that. If we're going to talk about the sun, far better to do so in terms of Bataille's solar excess: "The origin and essence of our wealth are given in the radiation of the sun, which dispenses energy - wealth - without return. The sun gives without ever receiving. Men were conscious of this long before astrophysics measured that ceaseless prodigality; they saw it ripen the harvests and they associated its splendor with the act of someone who gives without receiving. In former times value was given to unpro­ductive glory, whereas in our day it is measured in terms of production: Precedence is given to energy acquisition over energy expenditure. Glory itself is justified by the consequences of a glo­rious deed in the sphere of utility. But, dominated though it is by practical judgment and Christian morality, the archaic sensi­bility is still alive: In particular it reappears in the romantic pro­test against the bourgeois world; only in the classical conceptions of the economy does it lose its rights entirely." (The Accursed Share, Vol. 1).

In human terms scarcity is a valuation. We normatively value what is scarce.
Diamonds are scarce and they are considered (generally) more valuable than water, air, food which are all intrinsically necessary for life, but not nearly as scarce and therefore considered much less valuable.

Of course if a huge hoard of diamonds is found, then the value of diamonds falls economically and if there is a drought or a famine then water or food or both may become much more valuable. The value we place on what is scarce versus what exists in profundity is based on utility. The law of diminishing returns suggests that things have a certain utility and the more availability something is the lower its marginal utility.

Money provides the means of valuation of items that have no real connection (water vs diamonds), one of the great benefits of capital. It provides a medium of exchange by which we can measure the utility of what is exchanged.

As far as feelings, they're a kind of motion and all motions wear themselves out, or else they'd just be standing still. But they don't just wear themselves out in one direction -- you could say being tired 'fatigues itself' when the energy comes back. So nothing lasts forever and any particular good thing is going to end and not be good anymore, but that doesn't mean there's any guarantee of the eventual disintegration of everything.

things change

It's more like, what you feel is the change.