Why climate change is an engineering problem

The United Nations recently described climate change as the “defining crisis of our time” and one that is happening “even more quickly” than it could have possibly predicted. The burning of fossil fuels, deforestation, industry and overpopulation have certainly all played a part in forcing global temperatures to rise. This has ultimately led to more extreme weather events, rising sea levels, and the destruction of natural habitats. Policy-makers have often dragged their feet in a bid to halt these seismic changes. But - as the UN points out - we are not powerless to stop it, and science is increasingly coming up with new ways to tackle it. We’ll be examining some of the more innovative ways that researchers are engineering solutions to the climate crisis over the course of the programme. First though, here’s Mark Maslin, a professor of climate change at UCL and author of How To Save Our Planet…

Mark - Last year, 2023, was the warmest year on record, hitting an average of 1.48 degrees Celsius above pre-industrial levels. But even worse, if we look at the last 12 months, we have gone past the 1.5 degree target, which was set up by the Paris Agreement in 2015 by the leaders of the world. And the problem is that we haven't turned the corner. 2023 was the year when we emitted the most greenhouse gases ever in recorded history.

Chris - People often liken climate change to an oil tanker. Probably quite a difficult analogy to use, isn't it, given what's in the oil tanker. But the point being that this has a lot of momentum and when you want to stop the tanker, you don't turn the engine off at port because you will crash. You turn it off at sea and you aim to coast to a stopping point. So how far do we think the climate juggernaut is going to coast? Even if we do all these things now, how bad are things going to get?

Mark - We know if we stopped putting greenhouse gases into the atmosphere tomorrow, the temperature would stabilise where it is now. Great. The problem is, and I love your analogy of the oil tanker, the societies we live in have a predisposition to actually use fossil fuels because everything's built on it. The oil companies are making huge amounts of money. Countries are making tax dollars from those oil companies and therefore people are very reticent to actually move away from this cash cow. And also what I really like to point out to people is the International Monetary Fund monitors the amount of taxpayers money that is subsidising fossil fuel companies. And last year it came out to be about $1 trillion. That is about half the GDP of the United Kingdom. Every single year is being given straight to the oil and the gas companies to pollute our atmosphere which we, the taxpayer, will then have to pay to fix.

Chris - The problem is that we're going to get a lot of very old people, very cold in winter in countries like the UK, if we don't provide them with fossil fuels because we just haven't invested, and we're not alone in this, every country is guilty to some extent, but we haven't invested in the alternatives quickly enough, have we?

Mark - So we can shift things physically with good engineering and good policies very quickly. And the idea that the only way you can heat homes in cold countries is through gas is ridiculous when you look at Scandinavian countries where they all use heat exchangers.

Chris - Population of a Scandinavian country might be a couple of million. Population of one part of London is a couple of million. The housing stock we have in the UK is a lot of it Victorian. It's very poorly insulated and a heat pump just won't cut it. Not that the grid could cope with the demand either. So we find ourselves actually in a difficult position for multiple reasons. It's not just a question of we have to stop using gas. We've got a big headache with dealing with our ancient building stock, haven't we?

Mark - Well, for me, in the UK this is where climate change and other social issues become a win-win. We have some of the worst housing in the whole of Europe. And so therefore what we need is policies that say how do we improve the housing stock, so we actually move people in the UK from 19th century housing into 21st century housing, so they are healthy and have the environment they should have in one of the richest countries in the world.

Chris - We're going to hear a bit later on about making concrete in a more environmentally kind way. But that's going to be a big headache, isn't it? Because if we have to rehouse a large proportion of the population, if that's what you're saying is the engineering challenge that confronts us, then that's a lot of cement and that's an enormous carbon footprint.

Mark - So if we have a look at cement now. If cement itself was a country, it would be the sixth largest emitter of greenhouse gases in the world. But it's also absolutely essential. So what we need to do is think about ways that we can use technology to make it less polluting. Instead of just damning things and going, 'do you know what? Concrete, awful. We shouldn't use it.' No, but we should make it better.

Chris - What about energy sources and energy transmission? There've got to be some wins there. People keep talking about, for instance, a reevaluation of nuclear power and the concept of small modular reactors, that kind of thing. Do you think that is worth considering?

Mark - So for me, energy is absolutely key to solving the climate crisis. 80% of all the world's greenhouse emissions from energy comes from fossil fuels. Interesting fact, if we stop using fossil fuels completely, 40% of all ships on our high seas would not be required. That gives you the scale of how much fossil fuel we move around and how much we burn every single year. So if you look at the engineering solutions, renewables are simpler technology, cleaner technology, and local technology. I think the key technology will be in the second half of this century - fusion. Now fusion, the scientists have done their jobs. We have the actual scientific understanding, and we've created more energy than we put in. What is now the problem is it's a massive, and I mean a massive engineering problem, how do you take the laboratory and scale it up? Now the UK government has set aside land and money to try and build the first fusion sort of reactor in Nottingham, but it's going to take huge amounts of new engineering to actually produce that.