Search

Nature-based climate solutions have the potential to contribute to climate mitigation, but the vulnerability of land carbon to disturbances means that any efforts to slow or reverse land carbon losses will likely result in only temporary storage. Tonne-year accounting, which integrates the amount of carbon over the time that it remains stored, has been proposed as a method to measure the value of temporary relative to permanent carbon storage. Here we show that using tonne-year accounting to establish an equivalency of temporary with permanent storage is not grounded in climate science. However, a reimagined approach to tonne-year accounting could be effectively used as a metric to track the contribution of temporary carbon storage towards climate mitigation goals. We show that in a scenario where the total number of tonne-years accumulates at a constant or increasing rate, this results in a sustained or increasing climate benefit. However, as the rate of accumulation of tonne-years slows, this temperature benefit is eroded, and is lost completely when tonne-years stop increasing. This implies that if the world is able to sustain an increasing number of tonne-years alongside achieving net-zero fossil fuel CO2 emissions, then the resulting carbon storage (even if only temporary) would contribute to lowering peak temperature. Tonne-years of temporary carbon storage therefore have considerable climate value, not if treated interchangeably with permanent storage or fossil fuel emissions, but rather if quantified as an independent contribution to lowering the global temperature peak.

Strengthen markets, measures and definitions for removing carbon dioxide from the atmosphere to fight climate change. Strengthen markets, measures and definitions for removing carbon dioxide from the atmosphere to fight climate change.

The science and technology of the digital age is transforming society’s ability to monitor and understand the changing global environment. These transformations have built the foundation for the planetary intelligence needed to achieve the global sustainability goals. However, five key barriers need to be overcome.

There is growing recognition that meeting the climate objectives of the Paris Agreement will require the world to achieve net-zero carbon dioxide emissions around or before mid-century. Nature-based climate solutions (NbCS), which aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems, are increasingly being evoked as a potential contributor to net-zero emissions targets. However, there is a risk that any carbon that we succeed in storing in land-based systems could be subsequently lost back to the atmosphere as a result of either climate-related or human-caused disturbances such as wildfire or deforestation. Here we quantify the climate effect of NbCS in a scenario where land-based carbon storage is enhanced over the next several decades, and this stored carbon is then returned to the atmosphere during the second half of this century. We show that temporary carbon sequestration has the potential to decrease the peak temperature increase, but only if implemented alongside an ambitious mitigation scenario where fossil fuel CO2 emissions were decreased to net-zero during the time that NbCS-sequestered carbon remained stored. We also demonstrate the importance of non-CO2 climate effects of NbCS implementation; decreases in surface albedo that result from temporary reforestation, for example, have the potential to counter almost half of the climate effect of carbon sequestration. Our results suggest that there is some climate benefit associated with NbCS, even if the carbon storage is temporary, but only if implemented as a complement (and not an alternative) to ambitious fossil fuel CO2 emissions reductions.

There is growing recognition that meeting the climate objectives of the Paris Agreement will require the world to achieve net-zero carbon dioxide emissions around or before mid-century1–4. Natural climate solutions (NCS), which aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems5,6, are increasingly being evoked as a potential contributor to net-zero emissions targets7,8. However, there is a risk that any carbon that we succeed in storing in land-based systems could be subsequently lost back to the atmosphere as a result of either climate-related or human-caused disturbances such as wildfire or deforestation9–12. Here, we show that temporary NCS-based carbon sequestration has the potential to decrease the peak temperature increase, but only if implemented alongside an ambitious mitigation scenario where fossil fuel CO2 emissions were decreased to net-zero during the time that NCS-sequestered carbon remained stored. We also demonstrate the importance of non-CO2 climate effects of NCS implementation, which have the potential to counter a substantial portion of the climate effect of carbon sequestration. Our results suggest that there is some climate benefit associated with temporary NCS, but only if implemented as a complement (and not an alternative) to ambitious fossil fuel CO2 emissions reductions.

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.

The articles in this special section focus on how disruptions whether they be natural or human impact society, technological development, and future outlooks. This section explores the opportunities and challenges of leveraging AI and other digital capabilities to drive the transformative system changes needed to tackle the climate crisis and related global sustainability challenges. The work presented here was initiated well before the pandemic emerged, but the current crisis makes the issues explored in these papers even more poignant for challenges we face in building the world we want.

The world has changed. Posited to be a ‘super year’ for biodiversity with various international meetings and the conclusion of the Convention on Biological Diversity’s ten-year Aichi Targets, 2020 will be remembered for very different reasons: catastrophic fires, the COVID-19 pandemic, floods, locust outbreaks, a drastic drop in oil prices and widespread food insecurity. These disruptions will exacerbate the already considerable gap between rich and poor, hitting marginalized groups — the impoverished, women, Indigenous communities and people of colour — much harder. Impacts on the environment have been mixed: carbon emissions may be down, but there are growing concerns that nature will be forgotten in the rush to rebuild devastated economies.

Two major reports assessing global systemic risks have been published recently, presenting large‐scale panel data on the risk perceptions of different key communities, most notably business leaders and global change scientists. While both of these global communities agree on ranking environmental risks the highest, followed by societal, geopolitical, technological, and economic risks, business leaders perceive the likelihood of most risks as lower than scientists. This gap implies vexing questions in relation to building a shared sense of urgency and facilitating collective action. These questions need to be addressed through new ways of co‐creating risk assessments and strategic futures analysis.

The notion of a threshold of dangerous climate change has been central to national and international efforts to address climate risks. However, the focus on a single target has now become an obstacle because it reinforces three key problems: it frames climate change as a distant abstract threat, it impedes integration of mitigation and adaptation, and it fails to recognize the diversity of values and risk perceptions of people around the globe. We present an alternative framework that considers both biophysical science and social values in characterizing the broad spectrum of climate risks. The framework also presents the options for managing these risks within four quadrants defined by the inherent limits to mitigation and adaptation. This quadrant-based approach to managing the spectrum of climate risks restructures the climate change problem from avoiding a distant catastrophe to minimizing collective suffering.

The US climate movement has failed to create the political support needed to pass significant climate policy. It is time to reassess climate advocacy. To develop a strategy for philanthropy to strengthen climate engagement, I interviewed over 40 climate advocates,more than a dozen representatives from the foundation community, and a dozen academics. My assessment led me to conclude that climate advocates have focused too narrowly on specific policy goals and insufficiently on influencing the larger political landscape. I suggest four ways to improve climate advocacy: 1) Increase focus on medium and longer-term goals; 2) Start with people and not carbon; 3) Focus more on values and less on science; and 4) Evaluate what works and share what we learn. To accomplish these strategies, social scientists and advocates must work together to build a culture of learning. Meanwhile, philanthropy must empower experimentation and incentivize knowledge sharing.

Even with aggressive global action to reduce greenhouse gas emissions, the climate will continue to change for decades due to previous emissions and the inertia in biogeophysical and social systems. Therefore, as a complement to mitigation actions, society must also focus on enhancing its capacity to adapt to the unavoidable impacts of climate change that we are already experiencing and will continue to experience over the next few decades. Resource managers, regional planners, and government agencies need to consider climate risks in their planning. We provide an overview of climate change scenarios for California and suggestions on the use of climate projections in state and regional planning efforts in the future.

It is time to acknowledge that global average temperatures are likely to rise above the 2 °C policy target and consider how that deeply troubling prospect should affect priorities for communicating and managing the risks of a dangerously warming climate.

Experts, government officials, and industry leaders concerned about the sustainability of shrimp aquaculture believe they know what farmers need to know and should be doing. They have framed sustainability as a technical problem that, at the farm level, is to be solved by better shrimp and management of ponds and businesses. Codes of conduct, standards, and regulations are expected to bring deviant practices into line. Shrimp farmers are often cornered in a challenging game of knowledge in which their livelihoods are at stake. In the commodity chain there are multiple relations with both suppliers and buyers, not all of which are trustworthy. The social networks shrimp farmers belong to are crucial for sifting out misinformation and multiplying insights from personal experience in learning by doing. Successful farmers become part of a learning culture through seminars, workshops, and clubs in which knowledge and practices are continually re-evaluated. The combination of vertical and horizontal relationships creates a set of alternative arenas that together are critical to bridging knowledge and action gaps for shrimp farmers. Government and industry initiatives for improving links between knowledge and practice for sustainability have largely succeeded when incentives are aligned: shrimp grow better in healthy environments, and using fewer resources means higher profits.

In response to an Executive Order by California Governor Schwarzenegger, an evaluation of the implications to California of possible climate changes was undertaken using a scenario-based approach. The "Scenarios Project" investigated projected impacts of climate change on six sectors in the California region. The investigation considered the early, middle and later portions of the twenty-first century, guided by a set of IPCC Fourth Assessment global climate model runs forced by higher and lower greenhouse gas emission scenarios. Each of these climate simulations produce substantial impacts in California that would require adaptations from present practices or status. The most severe impacts could be avoided, however, if emissions can be held near the lower end of global greenhouse gas emissions scenarios. It is increasingly apparent that the rising atmospheric concentration of greenhouse gases (GHGs), resulting from human activities, is changing the climate in ways that pose serious risks to California's health, economy, and environment. Furthermore, the more GHGs accumulate in the Earth's atmosphere, the more the climate is likely to change and the greater the risks that Earth's system processes and society will face (IPCC 2007). If actions are not taken soon, substantial impacts are likely to happen sooner and grow to larger magnitudes.

In this paper we propose a framework for evaluating how prepared California resource managers are for risks of continued climate change. The framework presented suggests three critical dimensions of preparedness - awareness of climate-related risks, analytic capacity to translate such climate risks information into specific planning and management activities, and the extent of actions taken to address the risks. We illustrate the application of this framework in this paper through preliminary research of California coastal managers where we identify limited awareness of climate-change related risks, limited analytic capacity, and significant constraints on the abilities of institutions and individuals to take adaptation actions. Our analysis suggests that for California to realize its significant adaptive capacity and be able to manage the unavoidable impacts of climate change, resource managers need to be engaged more effectively in future discussions of managing climate risks in the state.

Over the last few years, California has passed some of the strongest climate policies in the USA. These new policies have been motivated in part by increasing concerns over the risk of climate-related impacts and facilitated by the state's existing framework of energy and air quality policies. This paper presents an overview of the evolution of this increased awareness of climate change issues by policy makers brought about by the strong link between climate science and policy in the state. The State Legislature initiated this link in 1988 with the mandate to prepare an assessment of the potential consequences of climate change to California. Further interactions between science and policy has more recently resulted, in summer of 2006, in the passage of Assembly Bill 32, a law that limits future greenhouse gas emissions in California. This paper discusses the important role played by a series of state and regional climate assessments beginning in 1988 and, in particular, the lessons learned from a recently completed study known as the Scenarios Project.

▪ Abstract In this review, we highlight new insights into the conceptualization of the vulnerability of social-environmental systems and identify critical points of convergence of what otherwise might be characterized as disparate fields of research. We argue that a diversity of approaches to studying vulnerability is necessary in order to address the full complexity of the concept and that the approaches are in large part complementary. An emerging consensus on the issues of critical importance to vulnerability reduction—including concerns of equity and social justice—and growing synergy among conceptual frameworks promise even greater relevancy and utility for decision makers in the near future. We synthesize the current literature with an outline of core assessment components and key questions to guide the trajectory of future research.

This paper examines the coastal ejido (collectives of peasant landholders) sector's response to the 1992 amendment to Article 27 of Mexico's Constitution, which for the first time legalized the sale and rental of ejido lands. Our analysis is based on a case study of southern Sonora, Mexico. The results indicate a shift in land tenure from the ejido to the private sector and a corresponding conversion of coastal lands to shrimp aquaculture ponds. Our analysis suggests these land-tenure and land-use changes, and the implications of these changes for the coastal ejido sector, vary depending on the historical, geographic and socio-economic characteristics of the ejido communities.

This paper introduces an analytical framework for evaluating the vulnerability of people and places to environmental and social forces. The framework represents the relative vulnerability of a variable of concern (e.g. such as agricultural yield) to a set of disturbing forces (e.g. climate change, market fluctuations) by a position on a three-dimensional analytical surface, where vulnerability is defined as a function of sensitivity, exposure, and the state relative to a threshold of damage. The surface is presented as a tool to help identify relative vulnerability in order to prioritize actions and assess the vulnerability implications of management and policy decisions.

We propose measuring vulnerability of selected outcome variables of concern (e.g. agricultural yield) to identified stressors (e.g. climate change) as a function of the state of the variables of concern relative to a threshold of damage, the sensitivity of the variables to the stressors, and the magnitude and frequency of the stressors to which the system is exposed. In addition, we provide a framework for assessing the extent adaptive capacity can reduce vulnerable conditions. We illustrate the utility of this approach by evaluating the vulnerability of wheat yields to climate change and market fluctuations in the Yaqui Valley, Mexico.

Studies of long-term soil and ecosystem development on static geomorphic surfaces show that old soils become depleted in most rock-derived nutrients. As they are depleted, however, static surfaces also are dissected by fluvial erosion. This fluvial erosion leads to colluvial soil transport on the resulting slopes, which in turn can rejuvenate the supply of weathering-derived nutrients to plants. We evaluated the influence of erosion and consequent landscape evolution on nutrient availability along a slope on the Island of Kaua’i, near the oldest, most nutrient-depleted site on a substrate age gradient across the Hawaiian Islands. Noncrystalline minerals characteristic of younger Hawaiian soils increased from 3% of the soil on the static constructional surface at the top of the slope to 13% on the lower slope, and the fraction of soil phosphorus (P) that was occluded (and hence unavailable) decreased from 80% to 56% at midslope. Foliar nitrogen and P concentrations in Metrosideros polymorpha increased from 0.82% and 0.062% to 1.13% and 0.083% on the constructional surface and lower slope, respectively. The increase in foliar P over a horizontal difference of less than 250 m represents nearly half of the total variation in foliar P observed over 4.1 million years of soil and ecosystem development in Hawai’i. The fraction of foliar strontium (Sr) derived from weathering of Hawaiian basalt was determined using 87 Sr: 86 Sr; it increased from less than 6% on the constructional surface to 13% and 31% on lower slope and alluvial positions. Erosional processes increase both nutrient supply on this slope and the fine-scale biogeochemical diversity of this old tropical landscape; it could contribute to the relatively high level of species diversity observed on Kaua’i.

The Yaqui Valley is one of the most productive agricultural regions in Mexico, and the adjoining waters of the Gulf of California are home to one of the nation’s most productive fishing industries. These two industries grew and prospered more or less independently for much their history. In fact, the Gulf of California was a source of food long before the Yaqui Valley was plowed and irrigated for wheat and other crops. Native peoples have lived along the shores of the gulf and fished its waters for millennia (Bowen 2004; Nabhan 2000; Robles-Ortiz and Manzo-Taylor 1972), while industrial shrimp trawlers began combing the gulf in the first few decades of the twentieth century (fig. 7.1). Then came agricultural development and the green revolution, which quickly transformed the Yaqui Valley from desert to wheat and created a new connection between land and sea—that of irrigation water and agricultural pollutants. The fishing and agricultural industries grew increasingly interconnected with the rise of the aquaculture industry in the late 1990s. Then, a series of privatization and liberalization policies combined with extended drought encouraged farmers to farm fish. As upland farmers turned to aquaculture, they were suddenly invested in the coast, and the terrestrial- and marine-based social and biological systems were connected to an unprecedented degree.

The vulnerability of people and places has emerged in the past decade as a central concern related to climate change (IPCC 2001; IHDP 2001) and a key question in the emerging field of sustainability science (see Clark et al. 2000; Kates et al. 2001; Turner, Kasperson, et al. 2003; Turner, Matson, et al. 2003; Eakin and Luers 2006). As it becomes increasingly clear that not everyone or every place is equally vulnerable to the rising frequency of environmental stresses, such as floods and drought resulting from climate change, or to major price shocks and policy changes, researchers and practitioners are seeking to understand what makes some places more vulnerable than others. What can be done to reduce the likelihood of harm for the most vulnerable? How can more resilient and adaptive communities and ecosystems be built or managed?

Recently, Popular Science disabled its online comments. In explaining this decision, the magazine cited research that showed that online comments, especially uncivil ones, strongly influence readers, often leading to misleading or incorrect interpretations of the articles. Popular Science wrote, “If you carry out those results to their logical end…you start to see why we feel compelled to hit the ‘off’ switch” [Labarre, 2013].

The vulnerability framework of the Research and Assessment Systems for Sustainability Program explicitly recognizes the coupled human–environment system and accounts for interactions in the coupling affecting the system's responses to hazards and its vulnerability. This paper illustrates the usefulness of the vulnerability framework through three case studies: the tropical southern Yucatán, the arid Yaqui Valley of northwest Mexico, and the pan-Arctic. Together, these examples illustrate the role of external forces in reshaping the systems in question and their vulnerability to environmental hazards, as well as the different capacities of stakeholders, based on their access to social and biophysical capital, to respond to the changes and hazards. The framework proves useful in directing attention to the interacting parts of the coupled system and helps identify gaps in information and understanding relevant to reducing vulnerability in the systems as a whole.

Global environmental change and sustainability science increasingly recognize the need to address the consequences of changes taking place in the structure and function of the biosphere. These changes raise questions such as: Who and what are vulnerable to the multiple environmental changes underway, and where? Research demonstrates that vulnerability is registered not by exposure to hazards (perturbations and stresses) alone but also resides in the sensitivity and resilience of the system experiencing such hazards. This recognition requires revisions and enlargements in the basic design of vulnerability assessments, including the capacity to treat coupled human–environment systems and those linkages within and without the systems that affect their vulnerability. A vulnerability framework for the assessment of coupled human–environment systems is presented.