Earth’s climate has been edging towards a scene usually reserved for a post-apocalyptic movie. Some posit geoengineering as a radical fix to climate change. Others say the risks are too high and its proponents mad. Welcome to the debate where science fiction meets climate science.

If you visit a block of land near the West Australian dairy town of Harvey in a few years’ time, you will see a few pipes sticking out of the ground, a solar panel and an aerial for communications devices. There may be a hut and some room for parking.

These will be the only visible signs of the South West Hub project, designed to test the feasibility of pumping megatonnes of carbon dioxide into the vast Wonnerup sandstone layer, a kilometre-and-a-half deep beneath the Jarrah-Marri trees on the surface.

The gas will be liquefied in a nearby compressor building – an anonymous farm shed – and transported to the injection site via underground pipes.

Wonnerup is an example of carbon capture and storage, one of a suite of technologies known as geoengineering, or climate engineering.

Geoengineering is a mixed bag, but the idea involves large-scale interventions at the level of the whole planet, with the goal of fixing the climate. It’s tricky, dangerous, and largely considered “fringe science”.

The proposals come in two main flavours. One is carbon dioxide removal, which strips the gas from the atmosphere and slowly restores atmospheric balance. A mix of techniques would be needed: hundreds of factories like Wonnerup, billions of new trees and plants, plus contentious technologies such as artificially encouraging the growth of plankton.

The second is solar radiation management, intended to cool the Earth by stopping the sun's heat from reaching the planet’s surface. That can be achieved by pumping minute particles into the atmosphere, but carries the risk of killing billions of people.

Right now, we don’t have the tools or the knowledge to deploy these fixes. But some prominent climate scientists argue that as carbon emissions continue to rise, geoengineering will have to be employed to avoid catastrophic climate change.