Ecology is the study of the relationships among living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism.
Human ecology is an interdisciplinary and transdisciplinary study of the relationship between humans and their natural, social, and built environments. The philosophy and study of human ecology has a diffuse history with advancements in ecology, geography, sociology, psychology, anthropology, zoology, epidemiology, public health, and home economics, among others.
In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities such as deforestation, fracking of the ground for oil extraction, pesticide sprayed in soil, and the introduction of exotic plant or animal species. Disturbances of sufficient magnitude or duration can profoundly affect an ecosystem and may force an ecosystem to reach a threshold beyond which a different regime of processes and structures predominates. When such thresholds are associated with a critical or bifurcation point, these regime shifts may also be referred to as critical transitions.
Brian Harrison Walker is a scientist specialized in ecological sustainability and resilience in socio-ecological systems.
In ecology, the theory of alternative stable states predicts that ecosystems can exist under multiple "states". These alternative states are non-transitory and therefore considered stable over ecologically-relevant timescales. Ecosystems may transition from one stable state to another, in what is known as a state shift, when perturbed. Due to ecological feedbacks, ecosystems display resistance to state shifts and therefore tend to remain in one state unless perturbations are large enough. Multiple states may persist under equal environmental conditions, a phenomenon known as hysteresis. Alternative stable state theory suggests that discrete states are separated by ecological thresholds, in contrast to ecosystems which change smoothly and continuously along an environmental gradient.
Planetary boundaries are a framework to describe limits to the impacts of human activities on the Earth system. Beyond these limits, the environment may not be able to self-regulate anymore. This would mean the Earth system would leave the period of stability of the Holocene, in which human society developed. The framework is based on scientific evidence that human actions, especially those of industrialized societies since the Industrial Revolution, have become the main driver of global environmental change. According to the framework, "transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental-scale to planetary-scale systems."
Stephen Russell Carpenter is an American lake ecologist who focuses on lake eutrophication which is the over-enrichment of lake ecosystems leading to toxic blooms of micro-organisms and fish kills.
A social-ecological system consists of 'a bio-geo-physical' unit and its associated social actors and institutions. Social-ecological systems are complex and adaptive and delimited by spatial or functional boundaries surrounding particular ecosystems and their context problems.
William Lee Steffen was an American-born Australian chemist. He was the executive director of the Australian National University (ANU) Climate Change Institute and a member of the Australian Climate Commission until its dissolution in September 2013. From 1998 to 2004, he was the executive director of the International Geosphere-Biosphere Programme, a coordinating body of national environmental change organisations based in Stockholm. Steffen was one of the founding climate councillors of the Climate Council, with whom he frequently co-authored reports, and spoke in the media on issues relating to climate change and renewable energy.
Johan Rockström is a Swedish scientist, internationally recognized for his work on global sustainability issues. He is joint director of the Potsdam Institute for Climate Impact Research (PIK) in Germany, together with economist Ottmar Edenhofer. He is also Professor in Earth System Science at the University of Potsdam and Professor in Water Systems and Global Sustainability, Stockholm University.
Diana Liverman is a retired Regents Professor of Geography and Development and past Director of the University of Arizona School of Geography, Development and Environment in the College of Social and Behavioral Sciences in Tucson, Arizona.
Carl Folke, is a trans-disciplinary environmental scientist and a member of the Royal Swedish Academy of Sciences. He is a specialist in economics, resilience, and social-ecological systems, viewing such systems as intertwined and potentially unexpected in their interactions. As a framework for resource management, this perspective brings important insights to environmental management, urban planning, and climate adaptation. He suggests ways to improve our ability to understand complex social-ecological interactions, deal with change, and build resilience, often working at smaller scales as a step towards addressing larger scales.
Caroline King-Okumu is an international development opportunities manager for the UK Centre for Ecology and Hydrology. She was formerly a senior researcher for the International Institute for Environment and Development (IIED). Her major areas of research are dryland ecosystems, economic and environmental assessment, and climate change. She is considered an international expert on land and water management, particularly drylands agriculture. King-Okumu is based in Kenya but is involved in research and projects throughout the world.
The Stockholm Resilience Centre (SRC), is a research centre on resilience and sustainability science at Stockholm University. It is a joint initiative between Stockholm University and the Beijer Institute of Ecological Economics at the Royal Swedish Academy of Sciences.
Malin Fredrika Sofia Sundberg-Falkenmark, born 21 November 1925) is a Swedish hydrologist. Falkenmark is best known for her long-standing work and expertise on the sustainable use of water resources to meet human and ecosystem needs. Her work is characterized by an integration of both natural- and social-science approaches. She is particularly known for developing what is now known as the Falkenmark Water Stress Indicator, an indicator used to measure and describe the water available for human use. She is the daughter of Halvar Sundberg.
Rosamond (Roz) Lee Naylor is an American economist focused on global food security and sustainable agriculture. She is the William Wrigley Professor of the Stanford University School of Earth System Science, and the founding Director of the Center on Food Security and the Environment at Stanford University. Her academic career has centered on environmental science and policy related to global food systems and food security. She is the President of the Board of Directors of the Aspen Global Change Institute, a Fellow of the Ecological Society of America, and a member of the Forest Protection Advisory Panel for Cargill.
Liette Vasseur is a Canadian biologist who has held the UNESCO Chair in Community Sustainability: From Local to Global in the Department of Biological Sciences since 2014 at Brock University in St. Catharines, Ontario, Canada. She is also a member of the Women and Gender Studies program and the Environmental Sustainability Research Centre. She is the President of the Canadian Commission for UNESCO.
Elena M. Bennett is an American ecosystem ecologist specializing in studying the interactions of ecosystem services on landscape. She is currently a Professor and the Canada Research Chair in Sustainability Science at McGill University. She was inducted to the Royal Society of Canada’s College of New Scholars, Artists, and Scientists in 2017. She was elected a member of the National Academy of Sciences in 2022 and became a Guggenheim Fellow in the same year.
Professor Reinette "Oonsie" Biggs is a South African sustainability scientist whose research focuses on food, water, and the benefits people receive from nature. Biggs is the co-director of the Centre for Complex Systems in Transition at Stellenbosch University, South Africa and a researcher at Stockholm Resilience Centre, Stockholm University in Sweden.
Beatrice Crona is an ecologist, a professor at Stockholm University, and the Executive Director of the Program on Global Economic Dynamics and the Biosphere at the Royal Swedish Academy of Sciences. In 2023 she became a Science Director of the Stockholm Resilience Centre.
