Ocean’s Role in Climate: Heat and Carbon Uptake in the Anthropocene

Lecture Series: Earth Transformed

Joellen Russell, 1885 Society Distinguished Scholar, Associate Professor, Department of Geosciences, College of Science, University of Arizona
Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat. Yet it is the least observed and understood region of the world ocean because of harsh conditions. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the ocean’s role in climate. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space. The second is that the climate modeling community finally has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean. Together with the observations, this new generation of models provides the tools to vastly improve understanding of the ocean’s ability to absorb anthropogenic carbon and heat both today and into the future.

Climate Change and Global Food Security

Lecture Series: Earth Transformed

David Battisti, Tamaki Endowed Chair, Professor of Atmospheric Science, University of Washington
By the end of the century, the season averaged growing temperature will very likely exceed the highest temperature ever recorded throughout the tropics and subtropics. By 2050, the increase in temperature alone is projected to cause a 20% reduction in the yield of all of the major grains (maize, wheat, rice and soybeans). The breadbasket countries in the midlatitudes will experience marked increases in year-to-year volatility in crop production. Increasing stresses on the major crops due to climate change, coupled with the increasing demand for food due to increasing population and development, present significant challenges to achieving global food security. This seminar explores the likely impact of climate change and volatility on food production and availability in the foreseeable future.

Ecosystem Resilience: Navigating Our Tenuous Connection to Nature

Lecture Series: Earth Transformed

Russell Monson, Louise Foucar Marshall Professor, Department of Ecology and Evolutionary Biology, Laboratory of Tree Ring Research, College of Science, University of Arizona
How can humans thrive within a natural world that holds the ingredients necessary for our survival, but at the same time is threatened by our domination of that world? Sustainability of the goods and services provided by Earth’s ecosystems is dependent on mechanisms of resilience that include maintenance of biotic diversity and avoidance of climatically-controlled ‘tipping points’. This lecture will explore how recent trends in land use and anthropogenic climate warming have exposed vulnerabilities in the mechanisms of ecosystem resilience, and revealed the potential for surprising shifts in the productivity and persistence of ecosystems. Recognition of the interactions between anthropogenic climate forcing and natural climate cycles, and breakthroughs in the fields of genomics and ecosystem modeling, provide opportunities for management of ecosystem resilience. With adequate foresight and focus, humans can learn to navigate toward a more sustainable future.

Climate Change and Human Health: Impacts and Pathways to Resilience

Lecture Series: Earth Transformed

Kacey Ernst, GIDP affiliate Global Change, Entomology and Arid Lands, Associate Professor, Department of Epidemiology and Biostatistics, College of Public Health, University of Arizona
Climate change induced impacts on human health are myriad; they range from direct effects, such as heat related mortality during extreme heat events, to indirect effects on infectious disease transmission systems. Predicting the degree of impact climate change will have on a specific health outcome becomes more difficult as the pathways become more indirect. One such example is determining the potential risk of dengue emergence in the U.S.-Mexico border region whereAe. aegypti mosquito populations that transmit the virus are well-established. A suitable natural environment is necessary but not sufficient for virus transmission. Social, economic, and behavioral factors can all enhance or reduce risk. While these factors make predictions difficult, they also suggest a level of control that we as a society have to reduce our risk of negative health outcomes linked to a changing climate. Both top-down and bottom-up actions must be taken now to mitigate current and future health threats.

Carbon Sequestration: Can We Afford It?

Lecture Series: Earth Transformed

Kimberly Ogden, Professor, Department of Chemical and Environmental Engineering, College of Engineering, University of Arizona
Climate change as a result of carbon dioxide emissions from industry and power plants (especially coal-fired plants) is a world wide concern. Global strategies are required such as those proposed by the International Energy Association, which states that a minimum of 1/6th of  CO2 future emissions must be captured and stored by 2050 to limit rises in average global temperature. Although there are many methods for capturing carbon, the primary barriers are testing them at a large scale, building an infrastructure to support them, and cost. These technologies include everything from injecting CO2 in the ground to recover oil to pumping it deep into the ocean to storing it in deep saline reservoirs to producing soil amendments.  In addition to reviewing these technologies, this lecture will discuss methods for reducing carbon emissions by using more alternative energy as well as CO2 uptake by microalgae to produce food and fuel.

The Changing Earth: It’s Not Just A New Normal

Lecture Series: Earth Transformed

Jonathan Overpeck, Thomas R. Brown Distinguished Professor,Regents Professor, Departments of Geosciences and Atmospheric Sciences, College of Science, Co-Director, Institute of the Environment, University of Arizona
It has been reported that climate change has generated a ‘new normal’ for our weather and our climate. True, but the new reality is less a single new climate than an ever-changing climate driven by the burning of fossil fuels and other human activities. The change is most noticeable at the global scale, but even in the Southwest the change is now firmly upon us in the form of unusually hot and severe drought, looming water shortage, widespread death of trees, unprecedented severe fire risk, dust storms, hotter heat waves and more. Climate change is likely driving the most pervasive and challenging transformations humans have yet faced. People from all walks of life will need to learn early and learn often how to adjust their plans and actions to the ever-changing new normal. Climate adaptation applied in concert with climate mitigation is the challenge of the century.

What is Life?

Lecture Series: Life In The Universe

Guy J. Consolmagno, SJ, Planetary Scientist, Vatican Observatory Research Group

Throughout history, our definition of 'life' reflects our assumptions about how the Universe works – and why we ask the question. The ways different human cultures, ancient and current, have talked about life provide some sense of how we have defined life, and illustrate the aspects of life that fascinate us. Many cultures used life as an analog to explain the movement of winds and currents, or the motions of the planets. Today we use those mechanical systems as analogs for life. Ultimately, we may not really know what life is until we have discovered more than one independent example of it on places other than Earth – we need many diverse examples before we can generalize. But without a definition of what we're looking for, and why we're looking, we may have a hard time recognizing life when we find it.

Planet Formation and the Origin of Life

Lecture Series: Life In The Universe

Dante S. Lauretta, Professor, Planetary Sciences/Lunar and Planetary Laboratory

It is generally accepted that planets or their satellites are required for life to originate and evolve. Thus, in order to understand the possible distribution of life in the Universe it is important to study planet formation and evolution. These processes are recorded in the chemistry and mineralogy of asteroids and comets, and the geology of ancient planetary surfaces in our Solar System. Evidence can also be seen in the many examples of ongoing planet formation in nearby regions of our galaxy. Finally, the variety of observable extra-solar planetary systems also provides insight into their origins and potential for life. These records will be discussed and compared to summarize our current understanding of planet formation and the accompanying processes that may lead to the origin of life throughout the Universe.


Life on Earth: By Chance or By Law?

Lecture Series: Life In The Universe

Brian J. Enquist, Professor, Ecology and Evolutionary Biology
Life on Earth is amazing and multifaceted. Ultimately all of life has descended from one common ancestor and has been guided by evolution by natural selection. On the one hand, the evolution of modern-day diversity and ecosystems may have been contingent on the initial chemical building blocks of life and the historical events that have characterized our planet over geologic time. On the other hand, there are numerous aspects of life pointing to regular and deterministic processes that shape the complexity and diversity of life. This talk will touch on those examples where the laws of chemistry and physics, in addition to evolutionary rules, have resulted in general properties of life. These properties ultimately determine how long we live, the diversity of life, the function and regulation of ecosystems and the biosphere, and how life will respond to climate change.

Complexity and Evolvability: What Makes Life So Interesting?

Lecture Series: Life In The Universe

Anna R. Dornhaus, Associate Professor, Ecology and Evolutionary Biology

Life is particularly fascinating in its ability to create complex and ever-changing forms out of simple building blocks. How does such complexity arise, and what are the conditions that allow never-ending evolution of new and more intricate forms of life? We now know that one of the main processes that allows this is that life consists of modules that interact with and feed back on one another. In the history of life on Earth, new levels of complexity have often arisen out of new types of such interactions, and continued evolution has been driven by life interacting with other life. We even find that man-made systems can develop a 'life' of their own when such feedback interactions among many modules occur. Life, it seems, is more about rules of interaction than special materials. We have only begun to understand the power of this algorithmic nature of life.