An urgent need for COP27: confronting converging crises.

The last 12 months have provided further evidence of the potential for cascading ecological and socio-political crises that were warned of 12 months ago. Then a consensus statement from the Regional Action on Climate Change Symposium warned: "the Earth's climatic, ecological, and human systems are converging towards a crisis that threatens to engulf global civilization within the lifetimes of children now living." Since then, the consequences of a broad set of extreme climate events (notably droughts, floods, and fires) have been compounded by interaction with impacts from multiple pandemics (including COVID-19 and cholera) and the Russia-Ukraine war.

Beyond 2020: converging crises demand integrated responses: Statement by the RACC International Advisory Committee following the RACC-12 International Forum.

The COVID-19 pandemic illustrates how the impacts of climate change are beginning to converge with other developing challenges with a likely peak with global population, requiring more integrated responses locally, regionally and globally.

Transitions to freshwater sustainability.

Fundamental transitions in natural resources technologies, institutions, and management approaches are often difficult to see in advance, or even in the midst, of actual changes. Such a transformation now appears to be underway for freshwater resources, driven by increasingly severe water-related crises around the world. These include mismatches between supply and demand; the continued failure to meet basic human needs for water and sanitation; expanding ecological degradation due to extraction of water from natural systems and human-caused climate changes; the development of new technologies for using, treating, monitoring, and reporting on water use; new conceptual work; and growing attention given to water issues by the public and scientific communities.

Reframing climate change assessments around risk: recommendations for the US National Climate Assessment.

Climate change is a risk management challenge for society, with uncertain but potentially severe outcomes affecting natural and human systems, across generations. Managing climate-related risks will be more difficult without a base of knowledge and practice aimed at identifying and evaluating specific risks, and their likelihood and consequences, as well as potential actions to promote resilience in the face of these risks. We suggest three improvements to the process of conducting climate change assessments to better characterize risk and inform risk management actions.

Sustainability. Systems integration for global sustainability.

Global sustainability challenges, from maintaining biodiversity to providing clean air and water, are closely interconnected yet often separately studied and managed. Systems integration—holistic approaches to integrating various components of coupled human and natural systems—is critical to understand socioeconomic and environmental interconnections and to create sustainability solutions. Recent advances include the development and quantification of integrated frameworks that incorporate ecosystem services, environmental footprints, planetary boundaries, human-nature nexuses, and telecoupling.

Roadmap for sustainable water resources in southwestern North America.

The management of water resources in arid and semiarid areas has long been a challenge, from ancient Mesopotamia to the modern southwestern United States. As our understanding of the hydrological and climatological cycles has improved, and our ability to manipulate the hydrologic cycle has increased, so too have the challenges associated with managing a limited natural resource for a growing population. Modern civilization has made remarkable progress in water management in the past few centuries.

Peak water limits to freshwater withdrawal and use.

Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new.

Global freshwater resources: soft-path solutions for the 21st century.

Twentieth-century water policies relied on the construction of massive infrastructure in the form of dams, aqueducts, pipelines, and complex centralized treatment plants to meet human demands. These facilities brought tremendous benefits to billions of people, but they also had serious and often unanticipated social, economical, and ecological costs. Many unsolved water problems remain, and past approaches no longer seem sufficient.