Caretakers of our planet

Climatologist and professor of Earth system science at University College London in the United Kingdom.



Article | 04:40 min read

Portrait of

Mark Maslin


London, UK

Still photography by

Adam Morris Philp

“Climate change is the greatest threat that humanity faces, but it is also our greatest opportunity. Just imagine if we actually decide to deal with this issue by working together as a global community, producing new ideas, innovative ways of actually dealing with environmental issues and working together as huge teams.”

Mark Maslin

Please introduce yourself.

I’m a scientist and I study the climate and I study the climate of the planet both in the past, the present and the future because I want to understand the mechanisms, what’s actually controlling climate change and how does it affect life on Earth. For me, I’m interested in human evolution. I’m interested in how humans are changing the climate now, and I’m interested in how we’re going to stop changing the climate and make it stable for future generations.

What are the greatest threats to this planet?

One of the greatest threats to our planet is climate change, because we are producing lots of greenhouse gases through burning fossil fuels and also changing the land use. We are increasing the amount of CO2 and the amount of methane. The amount of CO2 is increased by about 50 % since the industrial revolution, and we’ve doubled the amount of methane. And what that is doing is just heating up the planet more than it should be managed, changing our climate systems. It’s producing more extreme weather events and it’s starting to melt the ice sheets around the globe.

One of the side effects of climate change, which we hadn’t expected, is the acidification of our oceans. This is because when we put carbon dioxide into the atmosphere, some of it just a little bit of it dissolves into the surface ocean and makes a weak acid. Now, the oceans have been around for millions and millions of years. It’s actually where we evolved and came from. Life first came from the oceans. So therefore, the oceans have been incredibly stable environment for all that period of time.

Unfortunately, it means that the organisms that live in the oceans are not able to deal with this sort of change. They’re already starting to suffer due to this increased acidity. And this is going to get worse in the future. The shells are actually slightly dissolving. They are reproducing in less efficient ways, and therefore we’re starting to threaten the food webs in the oceans.

So in the future, we’re deeply worried that the oceans would become less productive or produce less fish, and therefore our resource where we rely on fish for food will become a lot less. And that’s a problem because we have a huge population to feed in the world.

But if we can stop our emissions as quickly as possible, then perhaps we can minimize the effects on the ocean and the food webs that we all rely on.

What happens when ice melts at the poles?

We are in a unique geological period of time where we have ice at both poles, both in the Arctic and on Greenland, but also on Antarctica. But because of climate change, these ice sheets are very vulnerable to melting. If you think about Greenland, if we melted the whole of Greenland, that could take hundreds of years, we would increase the sea level by five to seven meters. That’s an issue huge amount and would flood most major coastal cities.

What are your biggest worries about climate change?

My big worry about climate change is our ability to produce enough food to feed the world at the moment, half the food in the world is produced by small farmers on small plots of land that produce enough food for themselves and their family. But they also have enough to export to the local town and to the local cities.

This has been a very efficient way of actually producing food, but the problem is with climate change in the future, if the temperatures start to go up too much and humidity rises, suddenly, there are going to be more or more days when it’s physically impossible to go outside and work.

This is one of the great crises that people don’t talk about, because if they can’t produce enough food, then we are going to look at billions of people not having enough food to live and we will see some major food crises around the world.

What can you do as an individual to reduce climate change?

People feel as individuals, but they’re powerless to do anything about the world around them. But we’ve seen that this is not true. Individuals are so important when it comes to climate change. The first of all, I always say is talk to everyone. The more you talk to people, the more you engage them, the more they understand the challenge of climate change, but also how positive the solutions can be for everyone.

One thing you can do as an individual in a developing country is overnight. You can switch your energy supplier, switch from one that does fossil fuels to one that does renewables. In many countries, you won’t even see an increase in your bill, but automatically you will make a difference if everybody in your country did the same. That would be a huge incentive for energy companies to shift rapidly to renewable energy.

You can also use your car less. It means walking more, using public transport, meeting other human beings. You can also change the way you buy your cars instead of having a petrol or diesel car. Choose a hybrid or an electric car. It makes air so much cleaner in our cities, but it also reduces the amount of greenhouse gases and helps us save the planet.

Another win-win solution is if we move to a more vegetable based diet. Now, of course, the doctors will love this because we give up a lot of our meats, particularly processed meats. Suddenly, we all become much more healthy. We don’t have so many issues. And the interesting thing is, of course, that the carbon emissions of our normal diet can be halved just by going vegetarian. If we go vegan, then we can drop it down to a third.

Many of us have to fly for business. But if we can start to reduce the amount we fly, perhaps for personal reasons and even within business, we have to ask ourselves, is this really important enough to actually fly across the world? Then we can start to make a difference. If you have to fly, then again, one of the most important things you can do is you can offset the carbon emissions for that flight. Now, I would suggest that the best way to do that is entirely within your company have an offset scheme, which allows your company to reduce its footprint so you can actually balance your own travel against your own reduction targets.

One of the most powerful things individuals can do to shape the future is actually divest their pensions from fossil fuels. Pensions invest trillions of dollars of your money every year. If you turn around your pension company and say, I do not want you to invest in fossil fuels or you move your pension to a company that doesn’t, that suddenly sends a huge message to the economic power centers that says fossil fuels are dangerous investments, and therefore people do not want to invest in them.