Climate change adaptation is the ability of a society or a natural system to adjust to the (changing) conditions that support life in a certain climate region, including weather extremes in that region. The current discussion on climate change adaptation began in the 1990s, with the publication of the Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC). Since the beginning of the 21st century, most countries, and many regions and municipalities have started to develop and implement climate change adaptation strategies and plans. But since the implementation of adaptation measures must be planned and conducted at the local level, a major challenge is to actually implement adaptation to climate change in practice. One challenge is that scientific results are mainly published on international or national levels, and political guidelines are written at transnational (e.g., European Union), national, or regional levels—these scientific results must be downscaled, interpreted, and adapted to local municipal or community levels. Needless to say, the challenges for implementation are also rooted in a large number of uncertainties, from long time spans to matters of scale, as well as in economic, political, and social interests. From a human perspective, climate change impacts occur rather slowly, while local decision makers are engaged with daily business over much shorter time spans. Among the obstacles to implementing adaptation measures to climate change are three major groups of uncertainties: (a) the uncertainties surrounding the development of our future climate, which include the exact climate sensitivity of anthropogenic greenhouse gas emissions, the reliability of emission scenarios and underlying storylines, and inherent uncertainties in climate models; (b) uncertainties about anthropogenically induced climate change impacts (e.g., long-term sea level changes, changing weather patterns, and extreme events); and (c) uncertainties about the future development of socioeconomic and political structures as well as legislative frameworks. Besides slow changes, such as changing sea levels and vegetation zones, extreme events (natural hazards) are a factor of major importance. Many societies and their socioeconomic systems are not properly adapted to their current climate zones (e.g., intensive agriculture in dry zones) or to extreme events (e.g., housing built in flood-prone areas). Adaptation measures can be successful only by gaining common societal agreement on their necessity and overall benefit. Ideally, climate change adaptation measures are combined with disaster risk reduction measures to enhance resilience on short, medium, and long time scales. The role of uncertainties and time horizons is addressed by developing climate change adaptation measures on community level and in close cooperation with local actors and stakeholders, focusing on strengthening resilience by addressing current and emerging vulnerability patterns. Successful adaptation measures are usually achieved by developing “no-regret” measures, in other words—measures that have at least one function of immediate social and/or economic benefit as well as long-term, future benefits. To identify socially acceptable and financially viable adaptation measures successfully, it is useful to employ participatory tools that give all involved parties and decision makers the possibility to engage in the process of identifying adaptation measures that best fit collective needs.
Benjamin F. Zaitchik
Humans have understood the importance of climate to human health since ancient times. In some cases, the connections appear to be obvious: a flood can cause drownings, a drought can lead to crop failure and hunger, and temperature extremes pose a risk of exposure. In other cases, the connections are veiled by complex or unobserved processes, such that the influence of climate on a disease epidemic or a conflict can be difficult to diagnose. In reality, however, all climate impacts on health are mediated by some combination of natural and human dynamics that cause individuals or populations to be vulnerable to the effects of a variable or changing climate. Understanding and managing negative health impacts of climate is a global challenge. The challenge is greater in regions with high poverty and weak institutions, however, and Africa is a continent where the health burden of climate is particularly acute. Observed climate variability in the modern era has been associated with widespread food insecurity, significant epidemics of infectious disease, and loss of life and livelihoods to climate extremes. Anthropogenic climate change is a further stress that has the potential to increase malnutrition, alter the distribution of diseases, and bring more frequent hydrological and temperature extremes to many regions across the continent. Skillful early warning systems and informed climate change adaptation strategies have the potential to enhance resilience to short-term climate variability and to buffer against negative impacts of climate change. But effective warnings and projections require both scientific and institutional capacity to address complex processes that are mediated by physical, ecological, and societal systems. Here the state of understanding climate impacts on health in Africa is summarized through a selective review that focuses on food security, infectious disease, and extreme events. The potential to apply scientific understanding to early warning and climate change projection is also considered.
Christopher E. Clarke, Dylan Budgen, Darrick T.N. Evensen, Richard C. Stedman, Hilary S. Boudet, and Jeffrey B. Jacquet
The impacts associated with unconventional natural gas development (UGD) via hydraulic fracturing have generated considerable controversy and introduced terms such as “fracking” into the public lexicon. From a climate change perspective, transitioning from fossil fuels to renewable sources in order to potentially avoid the worst consequences of a warming planet will need to also consider the climate implications of increased UGD and natural gas use that follows. Specifically, how much greenhouse gas is emitted as natural gas is extracted, transported, and consumed relative to other energy sources? Is UGD a “cleaner” energy source? Compared to what? Does it postpone or “bridge” the transition from fossil fuels to renewable energy? Public perception of UGD’s climate impacts not only reflect individual attitudes but broader social discourse among stakeholder groups. Understanding these perceptions, their psychological and social factors antecedents, and how to engage audiences on this topic will play a key role in UGD’s long-term trajectory, especially as it relates to climate change. An added challenge is that most public opinion studies specific to UGD’s climate impacts (and indeed UGD in general) are limited to the United States, Canada, and a few countries in Europe and Africa, with other parts of the world entirely absent. Nonetheless, the studies that do exist highlight several common themes. In particular, UGD tends to be viewed as cleaner relative to fossil fuels because of the belief it produces less carbon emissions as a result of natural gas extraction and consumption. However, it tends to be viewed as dirtier relative to renewables amid the belief that it increases carbon emissions. This finding complements research showing that natural gas occupies a middle ground between renewables and other fossil fuels in terms of acceptance. Moreover, the extent UGD serves as a bridge energy source remains contentious, with some arguing that it and the natural gas it produces complement fossil fuels and facilitates a transition to renewables, while others claim that UGD entrenches society’s continued reliance on the former. Overall, despite the contentious nature of these issues, UGD’s climate impacts appear less salient across countries than other health, environmental, and economic impacts, perhaps because they are psychologically distant and difficult to experience directly. Amid efforts to convey the public health risks associated with a changing climate, we believe that emphasizing the public health dimensions of UGD’s climate impacts can potentially make them more psychologically tangible. Positively framed messages emphasize that reducing carbon emissions tied to both unconventional natural gas extraction and natural gas consumption (relative to other fossil fuels) and thus mitigating the resultant climate change that follows benefits public health. Conversely, negatively framed messages emphasize that increasing carbon emissions (relative to renewables) and thus amplifying the resultant climate change adversely affects public health. At present, though, there is little evidence as to how these messages affect the perceived connection between UGD’s climate impacts and public health and, in turn, support for UGD versus other energy types. Nor is it clear how these outcomes may vary across countries based on public sentiment toward UGD and climate change along with a variety of psychological and social factors that influence such sentiment. Data available for some countries offers tantalizing scenarios, but we remain limited due to the lack of social science research in countries outside the United States and a handful of others. We call for cross-national comparative studies that include places where UGD—and social science research on it—is still maturing.
Luisa Fernanda Lema Vélez, Daniel Hermelin, María Margarita Fontecha, and Dunia H. Urrego
Colombia is in a privileged position to take advantage of international climate agreements to finance sustainable development initiatives. The country is a signatory of the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol, and the Paris Agreements. As a non-Annex I party to the UNFCCC, Colombia produces low emissions in relation to global numbers (0.46% of total global emissions for 2010) and exhibits biogeographical conditions that are ideal for mitigation of climate change through greenhouse gas sequestration and emission reductions. Simultaneously, recent extreme climatic events have harshly compromised the country’s economy, making Colombia’s vulnerability to climate change evident. While these conditions should justify a strong approach to climate change communication that motivates decision making and leads to mitigation and adaptation, the majority of sectors still fall short of effectively communicating their climate change messages. Official information about climate change is often too technical and rarely includes a call for action. However, a few exceptions exist, including environmental education materials for children and a noteworthy recent strategy to deliver the Third Communication to the UNFCCC in a form that is more palatable to the general public. Despite strong research on climate change, particularly related to agricultural, environmental, and earth sciences, academic products are rarely communicated in a way that is easily understood by decision makers and has a clear impact on public policy. Messages from the mass media frequently confuse rather than inform the public. For instance, television news refers to weather-related disasters, climate variability, and climate change indiscriminately. This shapes an erroneous idea of climate change among the public and weakens the effectiveness of communications on the issue. The authors contrast the practices of these sectors with those of nongovernmental organizations (NGOs) working in Colombia to show how they address the specific climate communication needs facing the country. These NGOs directly face the challenge of working with diverse population groups in this multicultural, multiethnic, and megadiverse country. NGOs customize languages, channels, and messages for different audiences and contexts, with the ultimate goal of building capacity in local communities, influencing policymakers, and sensitizing the private sector. Strategies that result from the work of interdisciplinary groups, involve feedback from the audiences, and incorporate adaptive management have proven to be particularly effective.
H.E. Markus Meier and Sofia Saraiva
In this article, the concepts and background of regional climate modeling of the future Baltic Sea are summarized and state-of-the-art projections, climate change impact studies, and challenges are discussed. The focus is on projected oceanographic changes in future climate. However, as these changes may have a significant impact on biogeochemical cycling, nutrient load scenario simulations in future climates are briefly discussed as well. The Baltic Sea is special compared to other coastal seas as it is a tideless, semi-enclosed sea with large freshwater and nutrient supply from a partly heavily populated catchment area and a long response time of about 30 years, and as it is, in the early 21st century, warming faster than any other coastal sea in the world. Hence, policymakers request the development of nutrient load abatement strategies in future climate. For this purpose, large ensembles of coupled climate–environmental scenario simulations based upon high-resolution circulation models were developed to estimate changes in water temperature, salinity, sea-ice cover, sea level, oxygen, nutrient, and phytoplankton concentrations, and water transparency, together with uncertainty ranges. Uncertainties in scenario simulations of the Baltic Sea are considerable. Sources of uncertainties are global and regional climate model biases, natural variability, and unknown greenhouse gas emission and nutrient load scenarios. Unknown early 21st-century and future bioavailable nutrient loads from land and atmosphere and the experimental setup of the dynamical downscaling technique are perhaps the largest sources of uncertainties for marine biogeochemistry projections. The high uncertainties might potentially be reducible through investments in new multi-model ensemble simulations that are built on better experimental setups, improved models, and more plausible nutrient loads. The development of community models for the Baltic Sea region with improved performance and common coordinated experiments of scenario simulations is recommended.
Konrad Ott and Frederike Neuber
The means to combat dangerous anthropogenic climate change constitutes a portfolio. Beside abatement of greenhouse gas emissions, this portfolio entails adaptation to changing climate conditions, and so-called climate engineering measures. The overall portfolio has to be judged on technical, economic, and moral grounds. This requires an in-depth understanding of the moral aspects of climate engineering options. Climate engineering (CE) is a large-scale intentional intervention either in carbon cycles (carbon dioxide removal; CDR) or in solar radiation (solar radiation management; SRM). The ethical discourse on climate engineering has gained momentum since the 2010s. The set of arguments pro and contra specific CE technologies constitute a vast landscape of discourse. Single arguments must be analyzed with scrutiny according to their ethical background, their normative premises, their inferential logic, and their practical and political consequences. CE ethics, then, has a threefold task: (a) it must suppose a solid understanding of different CE technologies and their risks; (b) it has to analyze the moral arguments that speak in favor or against specific CE technologies; and (c) it has to assess the impacts of accepting or rejecting specific arguments for the overall climate portfolio’s design. The global climate portfolio differs from ordinary investment portfolios since stakes are huge, moral values in dispute, risks and uncertainties pervasive, and collective decision-making urgent. Any argument has implications of how to design the overall portfolio best. From an ethical perspective, however, one must reflect upon the premises and inferential structures of the arguments as such. Analysis of arguments and mapping them logically can be seen as core business of CE ethics. Highly general arguments about CE usually fall short, since the diverse features of individual technologies may not be addressed by overarching arguments that necessarily homogenize different technologies. It can be stated with confidence that the moral profiles of CDR and SRM are highly different. Every single deployment scheme ought to be judged specifically, for it is a huge difference to propose SRM as a substitute for abatement, or to embed it within a comprehensive climate portfolio including abatement and adaptation, where SRM will be used sporadically and only for a matter of decades.
William K. M. Lau
Situated at the southern edge of the Tibetan Plateau (TP), the Hindu-Kush-Himalayas-Gangetic (HKHG) region is under the clear and present danger of climate change. Flash-flood, landslide, and debris flow caused by extreme precipitation, as well as rapidly melting glaciers, threaten the water resources and livelihood of more than 1.2 billion people living in the region. Rapid industrialization and increased populations in recent decades have resulted in severe atmospheric and environmental pollution in the region. Because of its unique topography and dense population, the HKHG is not only a major source of pollution aerosol emissions, but also a major receptor of large quantities of natural dust aerosols transported from the deserts of West Asia and the Middle East during the premonsoon and early monsoon season (April–June). The dust aerosols, combined with local emissions of light-absorbing aerosols, that is, black carbon (BC), organic carbon (OC), and mineral dust, can (a) provide additional powerful heating to the atmosphere and (b) allow more sunlight to penetrate the snow layer by darkening the snow surface. Both effects will lead to accelerated melting of snowpack and glaciers in the HKHG region, amplifying the greenhouse warming effect. In addition, these light-absorbing aerosols can interact with monsoon winds and precipitation, affecting extreme precipitation events in the HKHG, as well as weather variability and climate change over the TP and the greater Asian monsoon region.