In an interview on Science and Climate Change

Let’s start with your first book, Fixing Climate: The Story of Climate Science – and How to Stop Global Warming by Robert Kunzig and Wallace S Broecker.

One of the reasons for picking this book is that Wally Broecker is my guru. He has been a friend for nearly 40 years and is a big influence on my life. This book is partly the story of his scientific development through the years, starting from a geochemist working in a lab to being one of the most influential people working in the world on oceanography and climate change. I think Robert Kunzig did most of the actual writing based on talking to and following Wally while he was doing his work.

And what kind of hope does he offer for the climate crisis?

What he is saying is that we could and should remove carbon dioxide from the atmosphere, having put it there without realising what the consequences would be. He suggests (credibly in my view) that it is possible to remove it and that we need to find ways of doing that in order to restore the climate to something closer to a natural state.

In the context of climate change there are two main things that science can help us to do which are reflected in the books I have chosen. One is what you might call Plan A, which is how to find low carbon sources of energy and reduce our energy consumption, and the other is Plan B, the geoengineering idea to intervene directly to modify climate if we can’t achieve enough with Plan A.

But does he have any ideas about how he thinks it can be done?

Yes, because a colleague of his is someone called Klaus Lackner who is developing a rather clever method for removing CO2 from the air without using too much energy. There are lots of different ways of removing CO2, but the trick is finding a way to do it in a closed cycle, without using more energy than you generated in the first place, and so doing more harm than good in the process.

In an interview on Climate Change

It’s an anti-national solution really, isn’t it? We’d have to belong to a global state.

Probably, which is why my last book, Fixing Climate by Robert Kunzig and Wally Broecker, suggests an alternative solution – addressing the carbon that’s already in the atmosphere, sucking that carbon out and storing it away somewhere. It’s not to do with making energy from cleaner sources, it’s a sub category of geoengineering. But the authors of this book have been very keen to point out that it shouldn’t be classified as such because it has no side effects.

Whereas other fixes do?

Yes, most of them do, like filling the air with sulphates to stop so much sunlight reaching the surface of the Earth. That solution doesn’t deal with the fact that there’s still carbon in the atmosphere, acidifying the ocean, and if we ever stopped the sulphates it would get very hot very quickly. Sucking carbon out of the air is a fix the authors compare to the problem of sewage in the 19th century. There were people then who said there’s no point in trying to clean up the sewage because there’s too much of it. We’re always going to produce all this human mess. Well, the quantities are actually quite similar.

So how does the fix work?

It works through a clever sort of plastic polymer that attaches to the CO2 in the air. Then you put the plastic in a vacuum, flush it with steam which displaces the CO2, and then you put the CO2 somewhere safe, such as basalt rocks in Iceland.

Which lock in carbon?

That’s right. The gas fuses with the rock and becomes solid. Of course the advantage of that is that you get CO2 from all sources, and in addition you can put your capture funnel by the basalt rocks and capture carbon emitted all around the world, with no need for pipelines.

Why don’t we just turn it all into diamonds?

Like in Superman, you mean, when he makes Lois Lane a nice diamond out of a lump of coal?

Exactly.

The thing is it would take quite a lot of energy, and create quite a lot of CO2. But seriously, this is a book to read. It’s not just that Wally Broecker, one of the authors, is the scientist who originally coined the phrase “global warming”, it’s that the other, Rob Kunzig, is one of the finest science writers in the business. It’s a book with authority, but you could also read it just for the lovely prose.