Climate scientist Reto Knutti: Climate policy is domestic policy

Every month brings new record temperatures, floods, droughts and severe weather events. So, what needs to happen to reverse the trend? Do we have enough time to do that? And how can people who no longer want to hear about an impending climate catastrophe be persuaded to engage and take the necessary measures?

Reto Knutti, Professor at the Institute for Atmospheric and Climate Science at ETH Zurich, has some answers. As one of the world's leading climate scientists, Knutti has contributed to several reports by the Intergovernmental Panel on Climate Change (IPCC), and is one of the most in-demand climate experts in the German-speaking world.

Reto, a lot of people seem to get defensive when global warming and the need to make changes comes up.

Reto Knutti: Over the years, I have come to realise that you can't convince people of something by repeatedly telling them how bad the situation is. Research has shown that humans are not very rational. Our experiences, gut feelings and the people we are closest to hold much more sway in our lives. We're guided by images, stories and messages - much more than by facts. At the same time, there are more and more examples of how something that seemed like a sacrifice yesterday might not be a sacrifice in the future. In fact, in certain areas, the alternatives are already more attractive. The battery electric vehicle will prevail - not because people have to switch over to these cars, but because they are cheaper. They are quieter. They are more comfortable. With the right price incentives, heat pumps will prevail, because at the end of the day, they are cheaper than heating with oil. That's already happening with new builds.

Climate change is a global problem. Does that mean we need a supranational organisation with real powers and authority to address it?

I think we have recognised that the only way to deal with this problem is to tackle it together. But I don't think the answer is tasking a collective body with overseeing that job. Nations are sovereign and they will stay sovereign. Climate policy is first and foremost domestic policy - I've been saying that for years. International conferences are important as a forum for dialogue and political coordination - but every country must find solutions that are appropriate for their specific means, their population and their political and technological context. Sooner or later, countries will find solutions because it makes sense for them to do so - not because they are obliged to do so.

China is a model student when it comes to e-mobility and solar power, but it continues to build new coal-fired power plants. How does that make sense?

It's a sign of China's economic growth. To satisfy that growth, they have to do both at the same time. But there is no doubt that China recognises that the future lies in renewable energies. It has strategically and very skilfully taken over the entire market. It started with photovoltaics and has moved on to battery electric vehicles and the electrification of the economy in general. 

Let's imagine we stopped emitting greenhouse gases into the atmosphere from 2050 onwards. Would that be too late?

It would be better if we reached that point sooner. And what would it take to achieve that? It's a question of feasibility. Technical, economic, social and political feasibility. If we manage to achieve net zero by 2050, then we will probably be able to avoid the worst of it. However, the probability that we will miss the target is high. Not because we aren't able to achieve the transformation - but because we are not acting quickly enough. 

How do you explain this hesitancy?

2050 is the day after tomorrow. Politically and economically. We have to remember that we live in a society that sources over 80 per cent of its primary energy from fossil fuels. That said, we need to act quickly, because we are supposed to halve emissions by 2030. But that is incredibly ambitious when you think of the technical and social transformation required. That's why I say I would be happy if we achieved net zero by 2050.

So, if net zero is an ambitious goal, what will it take to get us there?

Measures have to be introduced everywhere, because all sectors generate emissions - primarily mobility, so cars, lorries, shipping and aviation. But buildings generate emissions too, as do industry, agriculture, services and waste management. In many countries, electricity generation is another major contributor. Most of the reductions, at least in the short term, will come on the back of increased efficiency, renewable energy and the electrification of the economy. We know how to do this - but we have to implement it. We need to promote battery electric vehicles, install more heat pumps, switch to solar, wind and hydropower, and increase efficiency. If we achieve all of that by 2030, we will have accomplished the lion's share. Then come the more difficult things.

What are those?

Agriculture, so the residual emissions from fertilisers, for example. We need alternatives for processes requiring high temperatures such as steel production; hydrogen is one possibility. To make aviation sustainable, we will need to switch to synthetic fuels. Then there's waste incineration, where we have to succeed in capturing and sequestering the emissions produced. So as you can see, we are up against a whole portfolio of challenges. But in the short term, there is no doubt that efficiency, electrification and renewable energy can take us a very big step forward.

How quickly can renewable energies actually replace oil, coal and natural gas?

Solar energy probably has the most potential because electricity from solar energy is extremely cheap. In good locations, solar power can now be produced for one and a half cents per kilowatt hour. But energy systems have to be able to supply electricity at all times and not just when the sun is shining. A resilient energy system uses a combination of numerous technologies. Wind energy is an ideal supplement, especially in winter. Then there is geothermal energy and, in countries like Switzerland, hydropower and reservoirs. Batteries are fine for storing energy for short periods. But we also need a well-developed grid and European electricity agreements. If the member states help each other out, the differences in terms of production and load can be balanced out well.

What is the financial sector's role in the transformation?

Financial investments have the potential to exert considerable leverage. Of course, it's ultimately up to the individual to decide, but your readers can have a positive impact through the way they invest their money. Investors today know that they have a responsibility and can have an impact when they invest in new technologies or exclude certain investments from their portfolio. Take the Science Based Targets initiative, or SBTi for short. Investors could say: "I will only invest in companies that have set SBTi targets." This is an effective approach because the SBTi also takes supply chains into account. On the flipside, however, some products are labelled as being green but are not really sustainable. So it is important to find, for example, a financial institution that properly collects the relevant data, quantifies companies' efforts and conveys those efforts transparently.