A large body of science now documents that if these problems continue to grow as they have over the past half-century, the result will be substantial harm to human wellbeing by 2050 ( Scientific Consensus on Maintaining Humanity’s Life Support Systems in the 21 st Century ), ( Barnosky et al., 2012 , 2014 ; Brown et al., 2011 ; Ehrlich and Ehrlich, 2013 ), even the possible collapse of civilization as we know it.

Increasing encroachment of humans into previously little-touched ecosystems is disrupting non-human communities and leading to more frequent and severe ‘spillovers’ of disease ( Barnosky and Hadly, 2015 ; Quammen, 2012 ). Our limited knowledge of the reservoirs and vectors of these potential killers means that we can only guess from where and when they will emerge. Climatic change is further increasing the odds that novel diseases will crop up in humans and the plants and animals on which we depend: most of the world’s diseases are tropical in origin, and as we build roads and destroy habitats there, we disrupt the native systems leading to an increased probability of exposure risk to us. Spillover from humans to animals is increasing as well—many of our wild, and sometimes migratory, animals are afflicted with antibiotic resistant forms of bacteria such as MRSA.

The grand challenge

The grand challenge for science and society, then, is how to solve the intertwined problems of human population growth and overconsumption, climate change, pollution, ecosystem destruction, disease spillovers, and extinction, in order to avoid environmental tipping points that would make human life infinitely more difficult. Researchers in many disciplines have long recognized this challenge, and discussed it widely, especially in academic circles, for more than four decades, both from the perspective of the natural sciences (Table 2) and the social sciences (Leach et al., 2013; Raworth, 2012). However, understanding the problems stops short of fixing them, if the inter-related facets of seemingly distinct issues are not recognized, and if few outside the scientific community realize or accept that the problems are serious and that solutions are at hand. Therefore, a huge challenge within academia is working across traditional disciplinary boundaries to connect different pieces of the solutions puzzle that are emerging from practitioners spread across many different specialties (Cash et al., 2003; Ramanathan et al., 2015). And, an even bigger challenge is to take the knowledge developed within academia and collaborate closely with stakeholders in ways that elicit significant action (Ehrlich et al., 2012; Gibbons, 1999; Klenk et al., 2015). This is especially important, since guiding the planet for the future will likely require some fundamental changes—not just in human economic and governance systems—but also in societal values. Engagement with religious leaders, local communities and businesses, subnational groups and the military and security sectors of society, recently starting to burgeon, are critically important to further these necessary conversations and impel action (CNA, 2007, 2014; PAS and PASS, 2014; Ramanathan et al., 2015; Under2MOU, 2015; Vatican, 2015; WBSCD, 2013a, 2013b).

Problem Solution Climate Disruption Reduce effects of climate disruption by decreasing greenhouse gas emissions, and by implementing adaptation strategies to deal with the consequences of climate change already underway. Viable approaches include accelerating development and deployment of carbon neutral energy technologies to replace fossil fuels; making buildings, transportation, manufacturing systems, and settlement patterns more energy-efficient; and conserving forests and regulating land conversion to maximize carbon sequestration. Adapting to the inevitable effects of climate change will be crucial for coastal areas threatened by sea level rise; ensuring adequate water supplies to many major population centers; maintaining agricultural productivity and for managing biodiversity and ecosystem reserves. Extinctions Slow the very high extinction rates that are leading to a global loss of biodiversity. Viable approaches include assigning economic valuation to the ways natural ecosystems contribute to human well-being and managing all ecosystems, both in human-dominated regions and in regions far from direct human influence, to sustain and enhance biodiversity and ecosystem services. It will be critical to develop cross-jurisdictional cooperation to recognize and mitigate the interactions of global pressures (for example, climate change, ocean acidification) and local pressures (land transformation, overfishing, poaching endangered species, etc.). Ecosystem Transformation Minimize transformation of Earth’s remaining natural ecosystems into farms, suburbs, and other human constructs. Viable agricultural approaches include increasing efficiency in existing food-producing areas; improving food-distribution systems; and decreasing waste. Viable development approaches include enhancing urban landscapes to accommodate growth rather than encouraging suburban sprawl; siting infrastructure to minimize impacts on natural ecosystems; and investing in vital ‘green infrastructure,’ such as through restoring wetlands, oyster reefs, and forests to secure water quality, flood control, and boost access to recreational benefits. Pollution Curb the manufacture and release of toxic substances into the environment. Viable approaches include using current science about the molecular mechanisms of toxicity and applying the precautionary principle (verification of no harmful effects) to guide regulation of existing chemicals and design of new ones. We have the knowledge and ability to develop a new generation of materials that are inherently far safer than what is available today. Population Growth and Consumption Bring world population growth to an end as early as possible and begin a gradual decline. An achievable target is no more than 8.5 billion people by 2050 and a peak population size of no more than 9 billion, which through natural demographic processes can decrease to less than 7 billion by 2100. Viable approaches include ensuring that everyone has access to education, economic opportunities, and health care, including family planning services, with a special focus on women’s rights. Decrease per-capita resource use, particularly in developed countries. Viable approaches include improving efficiency in production, acquisition, trade, and use of goods and promoting environmentally friendly changes in consumer behavior. Disease Limit road-building and penetration of intact tropical forests. Designate remaining tropical regions for limited dissection and extraction of resources. Better on-the-ground monitoring of the areas under resource extraction will help us ascertain where and when outbreaks are likely to occur. Since most global disease is a subset of tropical diseases, our focus should be on those areas in particular, but even temperate regions require vigilance—chronic wasting disease, for example, threatens wild and farmed animals alike in North America. Anticipate global disease outbreaks and increase collaboration for containment and treatment. Our experience with Ebola taught the world that we are woefully underprepared to coordinate and contain even very infectious diseases. Increased communication and collaboration here is critical.

In this Special Feature, we offer six examples of how researchers are addressing these challenges through the process of discovering new knowledge and relevant tools within academia, and sharing knowledge and learning from stakeholders outside the Ivory Tower. The examples take the form of three articles and three web sites. The Special Feature arose from the symposium “Avoiding Collapse: Human Impacts on the Biosphere,” at the 2015 American Association for the Advancement of Science Annual Meeting in San Jose, California, and the three articles are extensions of presentations that were conveyed there. To illustrate the key role of science and industry in developing new information technology that will be critical in identifying and responding to global change, Dawn Wright shares insights on digital resilience, and what that means for policy-making and conservation. Tyrone Hayes and Martin Hansen highlight the intersections between food production, environmental contamination, and some social and economic obstacles that stand in the way of sustainable agriculture. And Vice Admiral Lee Gun (Ret.) bridges the divide between science and society by assessing the national security implications of climate change—and expresses a view increasingly echoed at the highest levels of the national security community.

The three websites were constructed specifically to bridge the science-society divide. The Millennium Alliance for Humanity and the Biosphere was founded to connect scientists, humanists, activists and civil society in order to foster positive global change. The Consensus For Action website is an outgrowth of the Scientific Consensus on Maintaining Humanity’s Life Support Systems in the 21st Century: Information for Policy Makers (Barnosky et al., 2014) a document which has been circulated to political leaders worldwide and used in discussions leading to international climate agreements. The website provides a venue for policy makers to quickly digest why it is essential to immediately address the issues of climate change, extinctions, ecosystem loss, pollution, and population overgrowth; for scientists to indicate to policy makers throughout the world the importance of dealing with those key environmental issues; and for the general public to voice their support to policy makers for taking action. The third website (Figure 1), “Mapping the Impacts of Global Change: Stories of Our Changing Environment as Told By U.S. Citizens,” was developed to provide rapid and locally relevant information to everyone, from the general public to political leaders, about how these threats to humanity’s life support systems play out, and resulted from dialogues between university students and faculty, policy makers at the state through national levels, and everyday citizens (Mychajliw et al., 2015).

These six examples illustrate that there is no one-size-fits all approach for researchers to address today’s grand environmental challenges, but two common themes emerge. The first is that it is no longer enough to simply do the science and publish an academic paper; that is a necessary first step, but moves only halfway towards the goal of guiding the planet towards a future that is sustainable for both human civilization and the biosphere. To implement knowledge that arises from basic research, it is necessary to establish dialogues and collaborations that transcend narrow academic specialties, and bridge between academia, industry, the policy community and society in general. The second theme is that now is the time to rise to these scientific and communication challenges. The trajectories of population overgrowth, climate change, ecosystem loss, extinctions, disease, and environmental contamination have been rapidly accelerating over the past half-century. If not arrested within the next decade, their momentum may prevent us from stopping them short of disaster.