The belief that 'fixing' global heating through the application of technology is possible, even desirable, is not new, and the idea of using so-called geoengineering to solve the climate crisis has yet to register with the public. Nonetheless, under the radar, the approach is continuing to gain ground and – in some circles at least - a degree of respectability.

To those of us opposed to the whole notion of deliberately messing with the climate to sort out the unwitting mess we have already made of it, this is the thin end of a very dangerous wedge.

Technology

It is a truth much acknowledged, that when you find yourself in a hole, the best course of action is to stop digging. This applies as much to screwing with the climate as anything else – except even more so. The problem is, while global temperatures continue to ramp up, sea-level rise accelerates and extreme weather becomes the norm, we are still wielding the spade with as much relish as ever.

Consequently - and setting aside the small reduction arising from Covid-19 lockdown – we continue, year-on-year, to load the atmosphere with every increasing quantities of carbon dioxide and other greenhouse gases.

At the same time, our failure to reel in a runaway global carbon budget is adding ever more weight to the argument, that the only way we can knock that pesky global heating on the head is via some form of technological tweak.

The dawning idea that we have the ways and means to interfere intentionally and on a massive scale with the global environment goes back at least to the 1950s, when Edward Teller - ill-famed 'father of the H-bomb' - advocated weather modification for military purposes.

In later years, this putative inspiration for Dr. Strangelove went on to propose giant reflective mirrors in orbit, or the scattering of billions of tiny reflective spheres throughout the stratosphere, as possible ways of tackling rising global temperatures.

Backstop

Today, the techie schemes touted as having the best potential to check global heating and the climate collapse that marches in step with it, are less wild and wacky, but no less risky for that. Whether they involve blocking some of the sun's input (solar radiation management), easing the path of heat escaping from the Earth's surface (Earth radiation management) or sucking carbon dioxide directly or indirectly from the air – which does what it says on the tin – all the potential fixes are untried and untested.

As such, they are no more than planetary-scale experiments that carry no guarantee of success, nor a warranty against unforeseen consequences that – at worst – could be catastrophic.

In essence then, the concept of geoengineering – in whatever form – is an insurance policy; a backstop. As such, it's very existence turns hearts and minds away from the cause of the climate crisis and inevitably dilutes the urgency with which it must be addressed.

As we learned from the interminable Brexit negotiations, backstops are rarely a good idea. Inevitably, they sow mistrust, are invariably contrived and tailored to support vested interest. By their very nature, they are untried and untested and there is no evidence they will work.

Furthermore, the geoengineering backstop suffers from a major conceptual problem, in that it is aimed explicitly at tackling the symptoms of the climate emergency, rather than the cause.

Emissions

Geoengineering, then, is no panacea, nor does it constitute an either or choice vis a vis simply cutting back on emissions. On its own, in fact, it cannot work, and its adoption can only be considered in tandem with deep cuts in emissions.

In the absence of such cuts, schemes to suck carbon out of the atmosphere would have little, if any, useful impact. Even worse, any go it alone plan to artificially reduce global temperatures would inevitably become locked-in for the long term.

If, for some reason, such measures were curtailed suddenly at some future time, the result would be a precipitous and almost certainly catastrophic global temperature hike. In other words, geoengineering is not a silver bullet, rather – at best – it is a sticking plaster that might buy some time for the climate to heal; a backstop that – on its own – solves nothing.

So, let's get real. There is only one solution to the climate emergency - only one way to keep the global average temperature rise (since pre-industrial times) to below the 1.5°C guardrail – and that is by slashing greenhouse gas emissions now, at the rate the science demands.

Instead of inflicting reckless experiments upon an already damaged world, we need to be tooling up for meeting a global net zero carbon target as soon as we can. This can only be accomplished if we make emissions reductions - rather than economic growth - the priority, although there is plenty of evidence that the two can go hand-in-hand.

Action

This is eminently doable and there is plenty of historical precedent for such rapid transitions. After the Pearl Harbour attack by the Japanese in December 1941, for example, the US transformed its economy almost overnight. During the next twelve months, production of cars, merchant ships and sewing machines was replaced by tanks, aircraft carriers and guns, on a prodigious scale, as the country's war machine ousted consumer-based manufacturing.

We need the same thing to happen now. The signs of change are already here. In the UK, it looks increasingly likely that petrol and diesel cars will be outlawed by 2030. Just this week, Airbus Industries announced three designs for hydrogen-powered passenger planes that they expect to be in service within 15 years.

Oil company BP made it known recently that – in its view – demand for oil may already have peaked. In the US, a new report from the America's Pledge on Climate Change initiative showed how aggressive federal action could slash the country's emissions in half within just 10 years.

The bottom line, then, is that we don't need and don't want any more tinkering with our already fragile climate. It's not nice and it's not necessary.

Let's instead throw our weight behind emissions cuts that really bite, beginning with the UK-hosted COP26 Climate Conference in Glasgow later this year. Let no-one be in any doubt, provided we want it badly enough we can do this!

Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at University College London, a Co-Director of the New Weather Institute, a Patron of Scientists for Global Responsibility, Special Scientific Advisor to WordForest.org, and on the Scientific Advisory Board of ScientistsWarning. His new novel, Skyseed – an eco-thriller about geoengineering gone wrong – is published by The Book Guild.