Thomas Sutcliffe: Does my waste look big in this?

It might seem a little perverse to write about an art exhibition the day before it closes, but I'd like you to think of this as an exercise in waste reduction. Because, while the odd Royal Academy blockbuster or Tate Modern crowd-pleaser might reach their projected capacities, most shows – particularly those in commercial galleries of contemporary art – never get close to pulling in all the visitors they could physically accommodate and an even smaller proportion of those they might intellectually satisfy.

And while an art exhibition is, in one sense, an ecologically righteous kind of commodity, in which virtually every component is preserved for further use, it's hard not to feel that something goes missing when a well-curated show is dismantled – a one-off constellation of ideas and images that has often taken months to assemble. It's like chucking away a jar of jam that is still half-full. As Says the Junk in the Yard at Flowers East is a well-curated show, and as it is very much concerned with waste itself, it seems reasonable to give one last prod to potential viewers, who have today and tomorrow to make use of the show before it goes for recycling.

This is an exhibition that is simultaneously very good and full of rubbish. Sam Chatterton Dickson's subject as curator is the extravagant profligacy of modern consumer society, examined by a range of artists in sculpture, video works and paintings. As you might expect, quite a lot of the work is about repudiating the notion of rubbish itself by discovering aesthetic qualities in objects or scenes that would conventionally be considered repulsive or useless. An installation by Graham Hudson, for instance, uses black bin-liners and office fans to create a cartoonish dance of desire, while the photographs of Keith Arnatt give decomposing waste the close attention of a Julia Margaret Cameron portrait, refiguring squalor as a gloomy kind of abstract expressionism.

Other pieces are more cerebrally concerned with exactly when objects pass from utility to uselessness, such as a video work by an artist called Savage, who rescued discarded garments, cleaned and repaired them, and replaced them (carefully folded) where he'd found them; they sit poised between ownership and abandonment.

But it isn't really individual works that give this show its impact. It's the accumulated effect – and for once the inherent bittiness of a theme show (its tendency to bring together very different kinds of artist and work) contributes to that effect rather than diminishes it. What really animates the exhibition is the unsettling effect of categories so broken down and intermingled that you despair of getting them straight again.

Curiously, you could see the same kind of existential unease in Channel 4's show Dumped, which tricked a selection of reality television participants into living on a landfill site for three weeks. It wasn't just the rats and the smell and the dust that they found depressing, I think, but the kind of vertigo that is induced by a landscape in which apparently irreversible disorder is the only observable principle. A rubbish dump affronts that part of us which is hard-wired to sort things out – and it's an effect that is also at work in some of the more powerful pieces in Says the Junk in the Yard, such as Robert Polidori's photographs of abandoned buildings in Chernobyl, or Sophie Gerrard's pictures of an Indian recycling company, its yard piled high with half-dismembered computer components.

They induce a kind of itch in the mind, these pictures – a feeling of helplessness in the face of so many broken objects. You understand why the biblical Gehenna, a rubbish dump outside Jerusalem, proved such a fitting model for Hell. And when the dismay fades, you feel a kind of fury at the fiction of disposability that fuels any advanced economy. One of the best installations is by an artist called Andy Hsu, a kind of catafalque inside which rest the corpses of several badly made utensils. On the front, a video shows them at the point of failure, making the point that, far from being cheap, such objects are far more expensive than tools that actually work.

If all this makes Chatterton Dickson's show sound merely finger-wagging and preachy, then I've failed to convey its distinctive texture, which mixes appreciation and disgust in a genuinely unsettling way. It is – unlike most art shows – about what we don't much care to look at, but it doesn't simply rub your nose in unwanted sights so much as make you think about why we turn a blind eye so often. If you're not going to have to burn too much carbon to get there, I'd recommend catching it before it closes. Scrape the last bit of jam from the jar.