A new technique to alter DNA is offering humans the ability to take control of food, disease and our own reproduction as never before. The workhorse of this technology is Crispr-Cas9, often described as a pair of “molecular scissors”, which can be directed to a specific part of a genome and used to make changes ranging from deactivating a gene to correcting a genetic typo or even inserting new genetic material.

In her new book, Hacking the Code of Life, biologist Nessa Carey delves into the practicalities, ethics and controversies of the approach, including the recent claim that a Chinese researcher has applied the tool to human embryos, resulting in gene-edited babies who will pass their altered DNA on to following generations.

Many have reacted with alarm at the news that a scientist in China has produced gene-edited baby girls and say there was no health justification for the move. However, you seem more exasperated than horrified…

[I remember] just reading it and thinking, “Oh you have got to be kidding me that this guy had done this.” Exasperation is a brilliant description of it because we know that the use of this technology, gene editing generally, is something where we have to build societal acceptance. Both girls will probably be fine, [but] it has put a bomb under all the attempts to build international consensus, which is not helpful at the moment. That is exactly what happened with the controversy over GM crops – there was a lack of public engagement.

He Jiankui claimed last year that he helped to create world’s first genetically edited babies. Photograph: Mark Schiefelbein/AP

It seems whenever gene editing comes up, the worry about designer babies isn’t far behind…

It is a rational issue to consider because it ties into the issue of how we value other human beings. It means that we have to think more closely about disability. Gene editing is giving us tools that make all these questions much more urgent than they ever were before. For some conditions that are so devastating for the individuals involved, gene editing has now flipped the ethical question not from: “Is it ethical to intervene?” to: “Would it be ethical not to?”

How far back do you think the news from China has set the field?

They’ve jumped the gun by a good 10 or 15 years and in a field like human reproduction that’s actually really risky. This technology should be safe if used well, but there are an awful lot of things that need to be checked because science chucks out unexpected things. It really does highlight the thing that is most fantastic and the thing that is most worrying about gene editing, which is that it’s really easy.

It’s an incredibly democratised technology and it’s impossible to see how it can be controlled except through consensus. We have never had anything quite this accessible and easy to use, with such powerful consequences.

If you look at the lives saved by big pharmaceutical company drugs, it's extraordinary we cast big pharma as the villain

Rogue scientists can crop up anywhere, but having worked there for many years do you think China has a particular issue around ethics when it comes to research?

It’s not particular to China. When you think how fast China has changed, you get examples of bad behaviour happening very quickly, but they can be corrected very quickly as well. Everything happens on a bigger scale and at a faster rate in China. So we’re still seeing it maturing as a scientific community, but China will be a world leader.

Will it overtake the US and Europe?

Almost inevitably, because it’s so big. And there is so much money to spend on science there, they fund at an incredible rate. So China will be an absolute powerhouse of research, there’s no debate about that.

Many would argue that gene editing – and Crispr – have been a triumph for academia. While you are currently a visiting professor at Imperial College London, you previously left academia to work for pharmaceutical companies. Why?

I always knew I’d be a good academic, but I also always knew I’d never be a great one. But the main reason was that the whole rationale for me to get involved in biomedical research in the first place was to make a difference to patients. The kind of research I was doing – it was interesting to other scientists, but it was extremely unlikely it would ever really have patient benefit. So working in drug discovery in biotech and pharmaceutical companies seemed like a much better route into that.

Big pharma companies are often cast as villains…

There has been bad practice in big pharma, as there has been in every industry. But if you look at the millions of lives that have been saved by big pharmaceutical company drugs and vaccines, and when you look at the millions of lives that have been improved, it is quite extraordinary that we cast big pharma as the villain.

But they have been criticised for ignoring certain diseases, including rare conditions…

Big pharmaceutical companies are publicly listed, so they have to respond to shareholders, they have to generate profit. Pharmaceutical development carries a level of risk we don’t see in other sectors. I suspect my next book is going to be exactly about this: how the pharmaceutical industry has ended up so reviled and why is it in this mess. The pharmaceutical industry is far too important to leave to simple free-market economics.

When it comes to health, is the role of genetics misunderstood by the public?

Because we have so much more information now about what the genome does and why DNA is important, it can be really easy for that message to get miscommunicated – that everything becomes about “it is all genetics”. It is very rare that things we see in humans are absolutely completely driven by genetics. It’s not that we’re badly educated about DNA – we’re badly educated about risk and how to interpret messages about risk.

Some big initiatives are collecting and sharing huge numbers of genomes for research. Has this research delivered on its promise to improve health?

It hasn’t quite delivered yet, but it almost inevitably will in terms of giving us information about populations and risk levels within populations. But that’s the easy bit. The difficult bit is how you translate that into effective healthcare practice. With the UK’s 100,000 Genomes Project, the UK is fantastically positioned to be one of the best countries with an understanding of what genomic data means. Whether it becomes one of the best countries in the world for acting on that, doing reasonable healthcare interventions and using that data well, that’s the much harder bit.

• Hacking the Code of Life: How Gene Editing Will Rewrite Our Futures by Nessa Carey is published by Icon (£12.99). To order a copy go to guardianbookshop.com. Free UK p&p on all online orders over £15