He has a very close relationship with the sea and there are two aspects to his love of it, leisure and business, or, to be more exact in the latter case, science. Professionally, Carlos Duarte's achievements are as varied as they are impressive. He has been awarded the National Research Prize and has 25 years' experience at the CSIC. He has travelled round the world by boat to study the effects of climate change on the seas, and took the time to discuss the subject with us.
Tides come in, tides go out. Is that how we should imagine your life?
-It could be one definition.
Is the sea always the same?
It always looks different. The colour changes. The texture changes. The wind changes. The sea isn't the same at night as it is during the day. It is a landscape which is always in motion. The sunrises and sunsets are incredible out at sea.
-How and when did you fall in love with oceans?
-I believe it must have been from birth. I was born in Lisbon, although my mother is from Malaga, and I am a Spanish citizen. With that mixture in my blood, it was impossible not to love the sea from the start.
-About 70 per cent of the Earth's surface consists of seas and oceans. Are people generally aware of the dimensions?
-No. The sea is a habitat with three dimensions, but we only see the surface, the flat area. If we were able to go deep down into it we would discover a much greater diversity of species. It is a habitat completely different to the one we are accustomed to when we walk around on land.
-Is there anything left to explore?
-There is everything left to explore. If we laid all the underwater exploration which has been carried out so far in a straight line, it wouldn't cover 50 kilometres of those that Jules Vernes' Captain Nemo did. Trump says he is going to take Americans to Mars, but we don't even have suitable ships to explore the oceans.
-Does Man need the sea more, or does the sea need Man?
-Man needs the sea. The sea can do without Man altogether, and it did for millions of years. On the other hand, we depend on it, from breathing to eating. The sea is beneficial for our health and even for our psychological wellbeing. We depend on our oceans being healthy.
-Are we causing damage to ourselves, do you think?
-Every degradation of the oceans is a degradation of our quality of life and our potential for the future. The good news is that it is not irreversible. We have already made some progress and that should cheer us up. The sea hasn't been lost yet. Absolutely not.
-Did the deterioration begin with the industrial revolution?
-That is a good point of reference. When the industrial revolution occurred a great deal of damage had already been caused by hunting and some marine species had already been extinguished, but the development of steam power for ships turned fishing into a type of war against fish. We reached rock bottom in that sense around the year 2000.
-Is the sea like a gigantic sponge?
-Yes, especially with regard to heat and carbon dioxide. Because we have altered the composition of the atmosphere we have trapped the heat which used to escape into space. The sea absorbs 95 per cent of the excess heat we produce. So it acts like a sponge, absorbing the heat and also a third of the carbon dioxide we produce, but this capacity for absorption has limits. The rise in temperatures is making species suffer.
-One might be tempted to think that is a price that has to be paid for the development of societies.
-No. That would be like taking a risk on our own survival. We would be placing our economic and human development in danger. The ocean is all we have, to absorb the growth of humanity. There is no other way of obtaining food in a sustainable manner. We cannot accept that deterioration is a price which has to be paid. We have to change the narrative about sustainability to the one about recovery.
-People at bus stops talk about the weather, not about climate change.
-There are figures about climate change which are evident. We need to put those at the bus stops. Every month the amount of carbon dioxide we emit into the atmosphere increases, and that is the element that causes the change. However, the effect this has on temperature is measured in the longer term.
-How much talk about climate change reflects reality and how much is alarmist?
-There is confusion in society. A cold winter makes some people think climate change doesn't exist, but that isn't the way to measure it. We can check climate change by comparing the summers and winters of our childhood with those of now. It is a scientifically demonstrated reality. Yes, the way it is communicated can sound a bit alarmist at times.
-It seems difficult to fight against something which is invisible.
-People are accustomed to making decisions about risks and events in the long term. They buy life assurance and pension plans.
-What effect does the rising temperature have on the seas?
-The response of marine life to a rise in temperatures is that the animals and plants start to move towards areas in higher latitudes in search of colder waters. If the sardines move away, there won't be many of the famous 'espetos' that we eat in Malaga any more.
-How could global warming affect us in Malaga?
-As a result of the warming, the sea is producing less. When there is less plankton, the sardines will no longer have the quality, fat or size that they do now.
-Describe the Alborán sea in just a few words.
-It is a very important strip of ocean. In geography we learn that the boundary between the Mediterranean and the Atlantic is in Gibraltar, but in fact it isn't. The sea doesn't understand borders.
-What marine currents do we find in Malaga?
-The Atlantic water near Gibraltar is like a type of whirlwind, it creates swirls which change with the winds. That makes the sea very dynamic. That movement of the sea provides a great wealth of food in the form of plankton. And, at the same time, a wealth and flavour of fish you only find here.
-Jellyfish are also very common in the summer nowadays. Is it too soon to talk about a plague?
-There have always been jellyfish. Sometimes our memories fail us. The arrivals of jellyfish are in long cycles, normally 18 to 20 years. Now we are in a low period. There are other types of animal, like the Portuguese man of war, which cause alarm because their sting is very dangerous, but they are not really jellyfish. It isn't true that the numbers of jellyfish are increasing, locally or globally. What happens is that we are more exposed to them these days. There are more people on the beaches, and a lot of mobile phones to film them.
-There is no end to the contamination of the seas. Are we swapping fish for rubbish?
-Put like that, it seems a bit excessive. People always say that by 2050 there will be more plastic than fish, but in fact that is not the case. The state of the seas isn't as bad as people say. During our explorations, we came across a stock of fish which have never been fished. They are mesopelagic fish, at a depth of between 400 and 700 metres. The stock of those fishes is about 30 times greater than all the known species put together. The health of the oceans is better than we used to think. We have problems but we know how to solve them if there is enough willingness to do so. I insist, there will never be more plastic than fishes in the oceans. People shouldn't try to create fear.
-What's the most surprising thing you have ever found below the sea?
-I couldn't choose just one. I have dived more than 2,000 times, in many places in the world. I have seen a lot of things which have been special for some reason. I have also seen a lot of negative things, which are hard from an emotional point of view. Seeing how we ill-treat the ocean, for example. But even in the worst places there has always been something lovely as well.