2016 Roger Revelle Memorial Lecture

The Roger Revelle Memorial Lecture Series is a traditional element of IOC Executive Councils. It is named in honour of Roger Revelle, whose important contributions to the awareness of global change form the basis of many IOC initiatives today.

This year's lecture was given by Professor Ken Caldeira.

Ocean acidification and other stressors on marine systems: How can we help the oceans help us?

© UNESCO/Line Bourdages -
Prof. Ken Caldeira with the IOC Roger Revelle Medal.

8 June 2016, 14:30, Room II

For all of human history, life in the oceans have greatly helped humans. Marine life not only provides humans with food, but also can build structures such as coral reefs that help protect coastlines. Living things in the ocean also play central roles in the global carbon cycle.

Life in the oceans is confronted with a wide array of direct human challenges: overfishing, farm runoff, coastal development, industrial pollution, and so on. In addition to these challenges, climate change is warming and further stratifying the upper ocean, reducing nutrient supply to the well-lit near-surface ocean. Further, when the ocean absorbs carbon dioxide from the atmosphere, the ocean becomes more acidic, and this increased acidity makes it more difficult for many marine organisms to build their shells or skeletons.

For most of human history, humanity has been a relatively small force on the planet. What we did didn’t matter very much for most natural systems. But since the industrial revolution, humanity has become a geologic force, affecting our planet with an intensity and scale that will be clearly visible to geologists in the distant future.

To keep taking from the ocean, we have to give something back. If the ocean is going to continue helping us, we will need to help the oceans.

The central thing that we need to do to protect the ocean from ocean acidification and climate change is to convert our energy system into one that does not use the sea and sky as repository for our waste carbon dioxide – an energy system that does not depend on smokestacks or tailpipes.  

But there is much we can do to help ocean ecosystems become more resilient to the changes that will occur. There are other things we can do to help the oceans help us. We can get better at managing fishing, including establishing no-fish zones. We can work with farmers to control run-off, work with industry to identify and eliminate dangerous pollutants from the production system. We can develop our coasts sensibly, and recognize the value of building a sustainable relationship with the wild and untamed.


Prof. Ken Caldeira
Climate scientist, Carnegie Institution for Science (USA)

Ken Caldeira is a climate scientist at the Carnegie Institution for Science’s Department of Global Ecology and Professor (by courtesy) in the Stanford University Department of Earth System Science. Professor Caldeira has a wide-spectrum approach to analyzing the world’s climate systems. He studies the global carbon cycle; marine biogeochemistry and chemical oceanography, including ocean acidification and the atmosphere/ocean carbon cycle; land-cover and climate change; the long-term evolution of climate and geochemical cycles; and energy technology. Caldeira received his B.A. from Rutgers College and both his M.S. (1988) and Ph.D. (1991) in atmospheric sciences from New York University.

IOC-UNESCO Roger Revelle Memorial Lecture Series

Roger Revelle

The first IOC-UNESCO Roger Revelle Memorial Lecture took place in 1992. The series has opened each Executive Council of the Commission since.

Roger Revelle (1909-1991) was a pioneer in oceanography and in global ocean science cooperation who spearheaded efforts to investigate the mechanisms and consequences of climate change. He was one of the first scientists to recognize the potential dangers of rising levels of atmospheric carbon dioxide and to highlight the role of the ocean in the climate system and in climate variability.

In his introductory remarks to the first lecture of the series in 1992, then UNESCO Director-General Federico Mayor explained:
"As one of the authors of the Copenhagen Declaration, he stated most clearly in 1960 the importance of the ocean to humanity as a whole and the need to study the ocean from many points of view and through the concerted action of all nations. His foresight of three decades ago was remarkable. At a time when the ocean was viewed by most as basically a source of food and a medium for transportation, Roger inserted into the Declaration the following:
'the oceans exert a profound influence on mankind and indeed upon all forms of life on earth. The oceans are inexhaustible sources of water and heat, and control the climate of many parts of the world.' (...)
This is the essential legacy left by Roger Revelle: not only his work as a pioneer in the field of international co-operation in ocean science and as one of the founding fathers of the IOC of UNESCO, but also his implicit call to all of us to promote to the best of our ability the vision of equity and universality that he embodied."

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