“Arctic Changes Derived from Satellites” with Johnny Johannessen (NERSC, Norway)

During the last 3 decades there has been a dramatic decline in Arctic sea ice extent, age and volume. This decline is assumed to be connected to global warming and the corresponding regional Arctic Amplification response triggering multidisciplinary coupled atmosphere, ocean and sea-ice interactive processes and mutual feedback. However, although we have gained good qualitative understanding of these processes and feedback mechanisms we still lack proper quantitative insight. This is predominantly due to the limitation of the existing observing system to routinely collect collocated and multidisciplinary measurements across the broad range of spatial and temporal scales. To advance the knowledge gap it is therefore necessary to design and implement a systematic multi-modal data-driven analysis framework whereby one benefit from the synergy of satellite sensor measurements complemented with improved in-situ measurement capabilities and tools including models, data assimilation and artificial intelligence. This will be highlighted in this webinar whereby new findings on Arctic amplification and evidence of distinct sea ice deformation associated with passage of storm events will be presented. The results are derived from an ESA funded study led by Johannessen with partners from France (Ifremer, OceanDataLab and Novelties).

Johnny A. Johannessen (Prof. Dr.) is affiliated with the Nansen Environmental and Remote Sensing Center and Geophysical Institute at the University of Bergen, Norway. He has 35 years of experience in satellite remote sensing in oceanography and sea ice research and applications. In particular, he has focused on the use of satellite remote sensing to advance the understanding of upper ocean dynamics and air-sea-ice interaction associated with ocean fronts and eddies. He has also been involved in development and implementation of operational oceanography at national and international level and have had a central role in the transition to Copernicus Marine Environmental Monitoring Service (CMEMS). Johannessen has authored/co-authored more than 200 scientific and technical publications, reports and book articles of which 110 papers are published in International Peer Review Journals.

Webinar was recorded on June 2, 2022

“The Earth Energy Imbalance and its Implications” with Karina von Schuckmann (Mercator Ocean International, France)

Human-induced atmospheric composition changes cause a radiative imbalance at the top of the atmosphere which is driving global warming. This simple number, the Earth energy imbalance (EEI) is the most fundamental metric that the scientific community and public must be aware of as the measure of how well the world is doing in the task of bringing climate change under control. Combining multiple measurements and approaches in an optimal way holds considerable promise for estimating EEI and continued quantification and reduced uncertainties can be best achieved through the maintenance of the current global climate observing system, its extension into areas of gaps in the sampling, advance on instrumental limitations, and the establishment of an international framework for concerted multidisciplinary research effort. This talk will provide an overview on the different approaches and their challenges for estimating the EEI. A particular emphasis will be drawn on the heat gain of the Earth system over the past half of a century – and particularly how much and where the heat is distributed – which is fundamental to understanding how this affects warming ocean, atmosphere and land; rising surface temperature; sea level; and loss of grounded and floating ice, which are critical concerns for society.

Karina von Schuckmann (Dr., HDR) is a physical oceanographer specialized in ocean climate monitoring working at Mercator Ocean International, France. Her interest lies in understanding the role of the ocean in the Earth’s climate system, its changes and underlying processes involved, and how they can be best observed (in situ, remote sensing), monitored (reanalyses and operational systems) and estimated (analyses approaches, ocean indicator development) in support of a sustainable future development. She is – amongst others – the Lead of the Copernicus Ocean State Report, lead author of IPCC SROCC and AR6, member of the European Academy of Science and the GCOS/GOOS OOPC panel, and member of the ISSI Science committee.

Webinar was recorded on May 19, 2022


“Changing Northern Lands – Thawing Ground and Expanding Use” with Annett Bartsch (b geos, Austria)

Pronounced impacts of climate change are observed across the entire Arctic – ocean as well as on land – and they are expected to intensify. As permafrost thaws ground destabilizes and microbes are activated with local and global implications respectively. Soil carbon release into the atmosphere is amplified. High latitude permafrost regions are thus considered a tipping element in the Earth’s climate system. Several million people live on permafrost and the exploitation of natural resources has been continuously expanding across the Arctic for many decades. Earth Observation provides the means to monitor both, the relevant essential climate variables and the expanding land use. Specifically recent satellite missions in the framework of Copernicus offer the necessary level of detail. The presentation will provide insight into the potential of Earth Observation to reveal patterns of permafrost thaw as well as expanding direct human impact across the Arctic.

Annett Bartsch works in the fields of remote sensing, cryosphere and hydrology with focus on the Arctic. Her major interests are in observing climate change impacts on Earth from space, specifically understanding of impacts of permafrost thaw on carbon release and people. Her published works provide insight into remote sensing techniques suitable to efficiently monitor the land surface across large regions such as the Arctic, including novel applications and approaches. Annett received her MSc in Geography from FSU Jena, Germany (2000), her PhD from The University of Reading, UK (2004) and her venia docenti for ‚Applied Remote Sensing’ from Technical University Vienna, Austria (2011). She was a visiting professor at University of Salzburg and at LMU Munich. In 2017, she founded the Earth Observation company b.geos GmbH (Korneuburg/Vienna, Austria), which contributes to climate change related basic and applied research funded through ESA and Horizon 2020. It currently hosts Annett’s team of the ERC Synergy Grant project Q-Arctic. b.geos is a member of the Austrian Polar Research Institute which is a research consortium that promotes and coordinates research and education in the area of polar sciences.

Webinar was recorded on May 12, 2022 



“Future Food and Water Security – the Role of Remote Sensing“ with Wolfram Mauser (Ludwig Maximilians University, Germany)

Abstract: Food and water are central resources for human civilizations, yet a growing and more prosperous global population will stress the global resources. A future sustainabble development will have to a secure the supply of affordable food. This is through developing maximum efficiency in managing water, soil and mineral resources for food production. Space based remote sensing will be the indispesable data backbone, which feeds Digital Twins of each agricultural field of the Globe with the necessary information to simulate beforehand individual management decision of farmers for maximum effiency and sustainablility in securing food production. The presentation will give the theoretical background of twinning Earth Observation with advanced farm simulation models and give concrete examples on their application in the real world.

Wolfram Mauser works in the fields of hydrology, food security, remote sensing, and Earth System modeling. His major interests are in observing human impacts on Earth from space, the understanding of human-environment relations through simulation, and the impacts of limited water resources and climate change on global as well as regional food security. His book Water Resources: Efficient, Sustainable, and Equitable Use gives insights into integrative approaches towards sustainable future water use. Wolfram received his MS in Physics, MS in Geography, and his PhD in Hydrology from the University of Freiburg, Germany. He was a visiting scientist at NASA Goddard Space Flight Center and the University of Maryland and conducted extended research visits to Africa, China, India, and South America. Until end of 2021 he held the Chair for Geography and Remote Sensing at Ludwig-Maximilians-University in Munich and now supports the satellite based remote sensing services company, VISTA in Munich Germany.

Webinar was recorded on May 5, 2022

“The Habitability of Galaxies and the Spread of Life” with Raphaël Gobat (Catholic University of Valparaíso, Chile)

The idea of a plurality of worlds, in which the Universe is filled with a vast number of life-harboring planets similar to our own, has long fascinated philosophers and has become a durable part of popular culture. To this day no incontrovertibly habitable planet other than our own has been found, and this idea thus remains a bright hope. However, the rapid pace of exoplanet discoveries, and the large number of extrasolar planets now detected, have finally made possible statistical studies and the determination, albeit tentative, of true planetary distribution functions. Furthermore, our knowledge of the evolution of galaxies and the stars they contain is now mature enough that we can model their formation history from early times to the present day. By combining the two we can estimate the amount of potentially habitable planets in our galaxy and others. More speculative yet is the idea of “panspermia”, the exchange of life-seeding material between solar systems. However, while still entirely unproven, this concept can be explored on large scales through the application of habitability models to numerical simulations, yielding insights about the efficiency of possible seeding processes in different regions of the Milky Way.

Raphaël Gobat is a tenured assistant professor at the Catholic University of Valparaíso, in Chile. After graduating from the Ecole Polytechnique Fédérale de Lausanne (EPFL), he studied at the European Southern Observatory (ESO) and obtained is PhD from the Ludwig Maximilian University (LMU) in Munich, Germany. He then went on to work as a postdoctoral researcher at the Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), in France, and at the Korea Institute for Advanced Studies (KIAS) before moving to his current position in Valaparaíso. Raphaël Gobat is an astrophysicist specializing in very distant galaxies and galaxy clusters. Always fascinated by deep time, he maintains a strong interest in the history of life on Earth, which has led him to branch off into more astrobiological research subjects as well.

Webinar was recorded on April 7, 2022

“Space Weather, Space Climate and Habitability on Earth” with Thierry Dudok de Wit (University of Orléans, France)

Until the 1980s, surprisingly few scientists were interested in the possible impact of the variability in solar activity on the Earth’s climate, until this gradually became a hotly disputed topic. For many years, there was a belief that everything boiled down to the total solar irradiance, i.e. the amount of radiated energy received on top of the atmosphere. This picture has been shattered by the discovery of many other different mechanisms that can operate on a wide range of spatial and temporal scales. More importantly, these mechanisms are coupled, requiring a comprehensive approach.

There is now strong scientific evidence for a climatic impact of solar variability that is measurable but tiny compared to the enormous impact of human activities. But the challenge of understanding the role of solar variability is far from over. One open question is what happened during the Maunder Minimum (1645-1715) when there were episodes of colder and wetter weather in some parts of the world. This puzzle can only be solved by bringing together multiple clues (so-called proxies of past solar activity) and physical models.

In this quick overview of the main mechanisms, the speaker will highlight some of the challenges posed by this fascinating interaction between our habitable planet and our nearest star.

Thierry Dudok de Wit is a professor in solar-terrestrial physics at the University of Orléans, France. He graduated and obtained his PhD at the Polytechnic Federal School in Lausanne. He has many interests as he held different positions and gradually migrated from the fields of fusion plasmas to fluid turbulence, followed by dynamical systems and now solar terrestrial-physics. The common thread is a strong interest in methodological approaches to characterise physical processes. Today he’s deeply involved in the Parker Solar Probe mission as instrument lead CoI.

Webinar was recorded on March 31, 2022

“Life as an Agent of Sustaining Habitability” with Aditya Chopra (Visiting Fellow, Australian National University, AU) 

The pre-requisites and ingredients for life seem to be abundantly available in the universe. However, we have yet to find any evidence for extraterrestrial life. Our search for life beyond the solar system is steadfastly focused on searching for habitable planets. But what do we mean by ‘habitable’? Habitable for whom, and for how long? It is not clear that the conditions for the emergence of life (the Abiogenesis Habitable Zone) are the same as the conditions for sustaining life on a planet. Conventional models of habitability that consider mostly the physics and chemistry of habitability may not be sufficient to truly appreciate the ‘evolution of habitability’.

As a planet evolves, it may lose the potential for life to emerge but may still support a biosphere. Indeed, it may lose habitability altogether, as has been speculated has happened with Venus and Mars. In this talk, Adi will argue that biospheres could play a crucial role in maintaining habitable conditions on their host planets by interacting with the planetary environment.

If it is the case that only inhabited planets are habitable, then we have so far ignored what may be the dominant parameter controlling the habitability of a planet: the life on it.

Aditya Chopra is a visiting fellow at the Research School of Astronomy and Astrophysics at the Australian National University. Aditya is using our current knowledge about the origin and evolution of life on Earth over the last ~4 billion years to better understand the potential for, and the nature of, life elsewhere in the universe. One of his research themes is the investigation of the role that life plays in keeping its planet habitable, and to identify processes which might have been co-opted by life to regulate Earth’s habitability at different epochs. Such biotic processes might also offer detectable biosignatures of alien life beyond Earth! Aditya has spent time as a Marie Skłodowska-Curie Postdoctoral Fellow at the University of Groningen in the oLife Fellowship Programme. He has degrees in Chemistry and Astronomy and completed his PhD at the Research School of Earth Sciences and Mt Stromlo Observatory at The Australian National University.

Webinar was recorded on March 17, 2022


“Is Water and Rock all that is Needed? Geology, Life and Habitability” with Frances Westall (CNRS Orléans, France)

The classical definition of the habitable zone around a host star is the zone of orbits that allows liquid water on a planet’s surface, which recognizes the importance of water for life as we know it. Add rock with its nutrients, the CHNOPS elements (carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur) to the recipe and you have all you need to make life flourish. Or have you?  How about the supply of energy and the thermodynamic disequilibrium that is needed? What does this mean for the environments in which life emerged on Earth? Hypotheses range from deep sea vents, to beaches, to rivers and lakes or subaerial hot springs on land, and even deep faults! If life emerged on land and not in the sea, this precludes the appearance of life on the icy satellites in our Solar System or on ocean worlds.

Whatever the environment (and hydrothermal systems, whether subaqueous or subaerial, are the most popular), life emerged on Earth probably during the Hadean era (4.5-4.0 Ga) and appeared to have evolved very rapidly because, by 3.5 Ga, the more primitive chemotrophs (microbes obtaining their energy from oxidation of inorganic or organic substances) were joined by the more efficient phototrophs (that obtain energy from sunlight). These organisms were anaerobic, i.e. required environments without oxygen.

However, further evolution required substantial changes, not only the evolution of the oxygenic phototrophs that excreted oxygen, thereby oxidizing the surface of the Earth as well as the atmosphere, but also geological and tectonic changes to the Earth. Plate tectonics contributed to burying carbon, exporting it from the sediments and atmosphere and allowing oxygen levels to rise. Plate tectonics also recycles essential nutrients. A planet without plate tectonics would not remain habitable after all nutrients at the surface had been utilized. 

All of these factors need to be taken into consideration when looking for life elsewhere, in our Solar System or on exoplanets.


Frances Westall is director of research at the Centre de Biophysique Moleculaire Equipe exobiology of the French National Research Laboratory CNRS in Orléans.  The CNRS laboratory is associated with the Université d’Orléans.  Frances was born in Johannesburg, South Africa but grew up in the UK and studied geology at the University of Edimburgh. Her research focuses on the earliest life on Earth and its geological context. She does field studies of the earliest supracrustal terrains – including the Kapvaal Craton in South Africa and the Pilbara in Australia – and of fossil bacteria from the early Archaean. She is a leading member of the ESA ExoMars mission science team to search for life on planet Mars.

Webinar was recorded on March 10, 2022

“The Habitable Zone Hypothesis: A Critical Look” with David C. Catling (University of Washington, USA)

In the absence of observable biosignatures, the search for life beyond the solar system currently focuses on the search for habitable planets. In particular, the concept of the habitable zone (HZ) around a host star is an important assumption in exoplanet research. The HZ is the zone of orbits that allows liquid water on a planet’s surface, which recognizes the importance of water for life as we know it. The HZ concept was first alluded to in Newton’s Principia, but its current incarnation is tied to modern models of planetary climate. The boundaries of a HZ depend on the luminosity of a parent star and the concentration of greenhouse gases in a planet’s atmosphere. But what does “in the habitable zone” imply in terms of the likelihood of finding life? And would life necessarily be restricted to the HZ?

In this talk, David C. Catling will argue that the habitable zone can be thought of as a heightened probability of possible life on a planet within a restricted range of star-planet distances, which we use as a Bayesian prior to inform our search for life. The HZ is also a hypothesis that needs testing by observation. The conventional limits of the HZ are calculated with an Earth-like climate assumed to arise from a CO2–H2O-rich atmosphere on a rocky world, which, in principle, predicts trends of CO2 levels with star-planet distance. But such trends will be subject to considerable scatter caused by variable geophysical and physicochemical parameters of rocky planets and each world’s trajectory of atmospheric evolution. In fact, a planet in the HZ may not be habitable. Thus, there is more to the apparently simple concept of the HZ than meets the eye (or telescopic mirror).

David C. Catling is a professor in Earth and Space Sciences at the University of Washington, Seattle (USA). David is well known as a planetary scientist and as a geo- and astrobiologist whose research deals with planetary habitability, including how the environment and life on Earth co-evolved over billions of years. He has also been involved in NASA’s Mars and astrobiology research, for example, being on Science Teams for NASA’s Phoenix Lander and Mars Perseverance Rover. In addition to many scholarly papers, he’s also written two books in the past decade: for the lay person, Astrobiology: A Very Short Introduction (2013, Oxford University Press) and for researchers, with Jim Kasting, Atmospheric Evolution on Inhabited and Lifeless Worlds (2017, Cambridge University Press).

Webinar was recorded on March 3, 2022

“Life in Extreme Environments” with Ricardo Amils (Universidad Autónoma de Madrid, Spain)

Following the interest in the concept of habitability which will be conveniently discussed in the present series of talks, we need to introduce the importance of extremophiles to know the limits of life and in the search of life elsewhere in the universe. The official interest in extremophiles can be dated in the mid of the seventies after C. Woese introduced the notion of Archaea as the third Domain of life, based on his evolutionary studies on ribosomal RNA. To do that he selected many microorganisms growing in extreme conditions and concluded using the catalogs of oligonucleotide sequence from the ribosomal RNAs that in addition to true bacteria and eukaryotes existed a collection of extremophiles that although having a prokaryotic life style they had molecular properties close to the eukaryotic cells. Although the interest in extremophiles started many years before around the role of halophiles in the spoiling of cold fish preserved in salt and the discovery that the oxidation of the mining metallic components was due to acidophilic bacteria and not to the atmospheric oxygen. At the same time that the concept of Archaea was gaining new adepts T. Brock was describing the existence of hyperthermophiles associated to the volcanic areas of Yellowstone. Since then a race started to discover the most extremophilic organism. Due to their characteristics extremophiles are considered of interest in many biotechnological processes.

Ricardo Amils is an emeritus professor of microbiology at the Department of Molecular Biology of the Universidad Autónoma de Madrid (Spain). He did his PhD at the Faculty of Medicine of the Universidad de Buenos Aires (Argentina) and held two associate research positions at Dartmouth Medical School and the Chemistry Department of Columbia University (USA). He is an expert in molecular ecology of extreme environments having published more than 350 research papers. He served as Dean of the Faculty of Science of the Universidad Autónoma de Madrid, director of the Astrobiology and Planetology and Habitability departments at the Centro de Astrobiología, member of the Solar Exploration Group of ESA and interdisciplinary scientist of the ESA Mars Express mission. He received the NASA Achievement Award for its participation in the Mars Analog Research and Technology Experiment project. He is a member of the Academia Europeae since 2016.

Webinar was recorded on February 24, 2022