Lucky for you, the most impactful work in this environmental show about ‘hope’ doesn’t require a ticket because it’s located on top of the building across from the entrance. The Queen Elizabeth Roof Garden’s summer terrace has reopened, having been transformed by Paul Pulford and Grounded Ecotherapy into a lush, green oasis with a cooling microclimate and more than enough tall green items to make you forget you’re surrounded by the Southbank Centre’s sea of concrete. Proof that wide public impact can be had even when you’re starting off with nothing more than an empty slab and some eager volunteers.

That amazing transformation is perfectly in line with the goals of the exhibition, which isn’t the kind of eco-show that aims to shape your opinion or scare you with facts. That’s already been overdone, and an art gallery is often the wrong place for that anyway, as evidenced by the swiftness with which everyone at the press preview immediately walked right past Imani Jacqueline Brown’s science-fair display filled with too much small print and too few visuals. No, the goal is “to bring audiences closer to this overwhelming subject in ways that can spark active and imaginative responses”. Keeping in mind the art gallery setting, here the most successful artists and works are the ones that hit your senses without requiring you to read the wall text, or sub-titles of angry Brazilians shouting about Bolsonaro.

The opening room features an uprooted tree, dried and dead and so precariously balanced I was too wary to walk beneath it. Ackroyd & Harvey have hung giant, two-tone portraits of environmental activists but look closer, they’ve been grown from grass. Cristina Iglesias has provided a green glass meditation box, with seats so high your feet will dangle as you’re suspended above a swirling stream. There were also some memorable pieces that opted to merely depict Earthly elements, but the ones that incorporated nature directly into the work are the ones that both initially drew my attention and made me continue to think about the environment long after I’d left.

Featuring work from fifteen international artists that span three generations, there’s a wide range of media and some intriguing use of technology. Jenny Kendler “translates” human language into birdsong, and Hito Steyerl has made a giant LED from recycled bottles and vegetation, a sort of backwards-engineered eco-TV that flashes flowery imagery. It wasn’t much more than a screen saver, but it was still more engaging than the other three video installations where far more attention had been given to the way they were hung instead of making the content engaging.

And then there’s environmental art pioneer Agnes Denes’ The Living Pyramid. Already all over Instagram, it’s a somewhat superficial install that looks like a sad reject from the Chelsea Flower Show. Luckily it’s set against archival photos of her groundbreaking ‘Wheatfield – A Confrontation‘ intervention from New York City in the early 80s. It’s telling that a forty year old image still packs such a punch, because we’re long past the point of needing to raise awareness about humanity’s precarious environmental state. Which begs the question as to what an art exhibition could or even should do. It’s a challenge, admits Director Ralph Rugoff, who elaborates that artists “tell stories that cannot be grasped with a single glance… and art can reach us in ways that the news media can’t.”

Which is best evidenced by the extreme emotions you’ll read about Andrea Bowers’ flashing ‘Climate Change is Real’ neon sign. Whether you think it’s the epitome of twee or want a sticker of it for your reusable coffee cup, you can’t deny that polarising art keeps the conversation alive. Something for you to debate up on that lovely roof garden afterwards.