There is something uniquely tantalising about the concept of geo-engineering and the climate altering technologies it promises. If the history of civilisation is the story of mankind's steadily increasing dominion over the natural world, then the ability to tinker with the climate is arguably the final chapter. It takes us to the summit of Mount Olympus, rubbing shoulders with the gods.

The idea that we can respond to rising global temperatures by simply re-engineering the climate - which was given fresh impetus last week by the release of a new report from Bjorn Lomborg's Copenhagen Consensus Centre arguing that geo-engineering techniques could prove far more cost effective at lowering temperatures than curbing carbon emissions - plays into an appealingly optimistic understanding of modernity in which humankind has the technical answer to every problem it faces.

It is extremely tempting to sign up to a school of thought that runs, "we screwed the climate, but it's alright because all we have to do is re-engineer it and everything will be fine". It certainly has more immediate appeal than the increasingly depressing predictions from the world's climate scientists that we might just be doomed.

And yet you do not have to be a student of Greek mythology to understand that human beings with God complexes rarely fare too well - just watching a couple of James Bond films ought to be reminder enough.

Those who support geo-engineering may like to characterise its critics as modern day Cassandras who take perverse delight in bleak predictions and are fearful they will be out of job as soon as the climate change crisis is resolved. But this cheap cliché soon founders on the rocks of entirely legitimate concerns about the technical and moral efficacy of geo-engineering.

Take the proposal for "cloud ships" endorsed by Lomborg and the new Copenhagen Consensus Centre's report as the most promising geo-engineering technology. It certainly has a lot going for it. We know from the clouds that form behind shipping lanes that using ships to spray salt water into the air will form high level clouds that would serve to reflect back some of the sun's energy. Moreover, at a cost of around $9bn such a project would be extremely cheap in the grand scheme of things, while unlike proposals to pump particles into the atmosphere we could quickly stop the experiment if it had adverse effects.

But major problems still remain. First up, you barely need a GCSE in geography to understand that the weather and ocean current systems that shape our societies are influenced by both delicate variations in ocean temperatures and the difference between air temperatures over sea and land. Tinkering with these temperatures could have unforeseen and disastrous side effects thousands of miles from where the clouds are created.

Speaking to Lomborg last week, he admitted that more research was required into the likely side effects of cloud ships, but added that the proposed fleet would aim to operate in the Pacific in an attempt to reduce the impact on those rainfall systems that make landfall.

Of even greater concern is the fact that the project would only serve to mask the effect of climate change, not reverse it by addressing concentrations of greenhouse gases in the atmosphere.

This is worrying on a number of fronts. Firstly, it would mean that we would be signing up to maintaining and operating a fleet of cloud creating ships indefinitely, with all the future costs and risks that go with that.

Secondly, the failure to address rising concentrations of CO2 in the atmosphere would mean that the acidification of the oceans would continue to accelerate regardless of the project's success. When this point was put to Lomborg he suggested that the biggest environmental challenge put forward by green groups was rising global temperatures and as such it was "disingenuous" of them to highlight a different issue in response to a potential solution to global warming. Lomborg has a long history of windiong up environmental groups, but quite how raising awareness of the acidification of the world's oceans and the resulting collapse of an ecosystem that supports billions of people globally can be described as "disingenuous" is still not entirely clear.

Finally, the creation of any successful geo-engineering system would simultaneously create an unprecedented political and security challenge as world leaders attempted to negotiate who gets to play God and control the technology. Not that I wish to sound like those Bond villains, but whether it is cloud creating ships or "artificial trees" capable of capturing carbon from the atmosphere we are talking about technologies that could prove as powerful and destructive as a slow motion nuclear arsenal. If the UN's largely failed attempts to check nuclear proliferation have taught us anything it is that mistrust and posturing are the default setting when it comes to world-ending technologies and there is no reason to think geo-engineering will be any different.

Of course, none of these concerns are an argument to immediately end all research into geo-engineering and Lomborg and co may be right in calling for more research into geo-engineering as a last best hope of avoiding climatic disaster. But none of the proposals under discussion are in any way viable in their current form and if there is to be more research it has to be undertaken with no expectation of success lest the work serves to distract from the crucial fight to curb carbon emissions.

The only proposals on the table that could help address both rising temperatures and ocean acidification are sci-fi style "artificial trees" capable of extracting carbon dioxide from the atmosphere and storing it underground. But we already have a tried and tested way of creating larger carbon sinks - it is called afforestation and it has been shown time and again to be the most cost effective means of tackling climate change.

Equally, even the most successful geo-engineering technologies would do nothing to address the increasing level of energy insecurity that characterises our reliance on carbon intensive fuels. Again, we already have the proven technologies for simultaneously cutting carbon emissions and bolstering energy security in the form of everything from solar panels to hydroelectricity, and wind turbines to biomass plants.

The failure to roll these technologies out quickly enough should spur us on to act faster, not serve as a green light for another reckless gamble on technologies that are unlikely to ever work and will only create fresh problems even if they do. If there is one lesson that both Greek Myths and Bond films have in common it is that if something looks too good to be true, it almost invariably is.