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Previous studies have projected a significant role for bioenergy in decarbonizing the global economy and helping realize international climate goals such as limiting global average warming to 2 ˚C or 1.5 ˚C. However, with substantial variability in bioenergy results and significant concerns about potential environmental and social implications, greater transparency and dedicated assessment of the underlying modeling and results and more detailed understanding of the potential role of bioenergy are needed. Stanford University's Energy Modeling Forum (EMF) initiated a 33rd study (EMF-33) to explore the viability of large-scale bioenergy as part of a comprehensive climate management strategy. This special issue presents the papers of the EMF-33 study—a multi-year inter-model comparison project designed to understand and assess global, long-run biomass supply and bioenergy deployment potentials and related uncertainties. Using a novel scenario design with independent biomass supply and bioenergy demand protocols, EMF-33 separately elucidates and explores the modeling of biomass feedstock supplies and bioenergy technologies and their deployment—revealing, comparing, and assessing the modeling that is suggesting that bioenergy could be a key climate containment strategy. This introduction provides an overview of the EMF-33 study design and the overview, thematic, and individual modeling team papers and types of insights that make up this special issue. By providing enhanced transparency and new detailed insights, we hope to inform policy dialogue about the potential role of bioenergy and facilitate new research. [ABSTRACT FROM AUTHOR]

Using an experimental auction, we explore how verifiable information affects the willingness to pay (WTP) for two climate friendly goods given the politicized climate change debate. We test whether the dissemination of (scientific) verifiable information lets subjects cut through the media noise. We define our baseline by first examining how noisy information (pro and con) about climate change affects WTP. We then consider how third party verifiable information within this noisy information affects WTP. Our results suggest subjects could cut through noisy information to process verifiable information. We find a significant WTP premium for climate protection. The verifiable information treatment increases the premium for both shade-grown coffee (by 51 %) and recycled paper (by 48 %). This suggests the WTP premium for climate change depends on the available information flow and the characteristics of the climate friendly good. [ABSTRACT FROM AUTHOR]

Just over 40 years ago, I wrote a paper entitled 'Climate change: Are we on the brink of a pronounced global warming?' In it, I attempted to explain why despite a rise in the atmosphere's CO2 content there had been no significant warming. I predicted that a natural cooling was about to give way to a warming, and that industrial emissions of CO2 would amplify this warming. The paper published in Science in 1975. Warming did follow in 1976-1977. However, a retrospective look shows that my analysis was flawed. What is more-and to my chagrin-based on the words 'global warming' in my Science paper, I was given the title 'Father of Global Warming.' Not only did I not like this title, I had done little to merit it. [ABSTRACT FROM AUTHOR]

Though a small fraction of the US citizenry, agricultural producers are directly responsible for the stewardship of almost half of the country's land. This group is therefore an especially important one to understand from the standpoint of how they process and respond to science as it relates to agroecological phenomena. Data from a sample (n = 111) of farmers and ranchers located in the US state of Colorado are used to expand our understanding of how food producers process scientific claims. These insights, I argue, help us think through public understandings of science more generally. Using semi-structured interviews, the paper unpacks an identified asymmetry in how respondents perceive climate science and the science associated with genetically modified food and seed. These tensions are interrogated with the help of a novel methodological design that generated data converted to shading matrices—also known as heat maps. The heat maps illuminate certain cultural values among respondents, which were reinforced by motivated reasoning. This allows for an interrogation of tensions and inconsistencies in respondents' remarks about a variety of scientific claims. The heat maps, coupled with the qualitative data, allow for an exploration into how respondents perceive certain salient socio-technical issues. [ABSTRACT FROM AUTHOR]

The public education system can play a pivotal role in creating an electorate that is well informed of the consensus around climate change and its anthropogenic causes. In particular, more states have education standards that specifically address climate change today than ever before. However, previous research raises concerns about the discretion teachers have in if and how particular types of content are presented. The effectiveness of new state standards and the extent to which such state-level standards are coopted by teacher discretion has received minimal attention. Therefore, using a nationally representative sample of 1500 middle school and high school science teachers, this research examines the effectiveness of such state-level standards and the extent to which teacher ideology and knowledge mediate the relationship between standards and actual use of a consensus-informed approach to teaching climate science. Results show that teachers in states with any type of standards around climate change spend significantly more time on the topic in the classroom. However, teachers in states that have standards that require teachers to present "both sides" of climate change are significantly less likely to use a consensus-informed approach. While teacher characteristics (knowledge and ideology) can weaken their effect, standards continue to be important predictors of the time spent on climate change in the classroom and how content is presented. The paper concludes with a discussion of the policy implications of climate science standards. [ABSTRACT FROM AUTHOR]

The assessment of the impacts of climate change at different levels of global warming helps inform national and international policy discussion around mitigation targets. This paper provides consistent estimates of global and regional impacts and risks at increases in global mean temperature up to 5 °C above pre-industrial levels, for over 30 indicators representing temperature extremes and heatwaves, hydrological change, floods and droughts and proxies for impacts on crop yields. At the global scale, all the impacts that could plausibly be either adverse or beneficial are adverse, and impacts and risks increase with temperature change. For example, the global average chance of a major heatwave increases from 5% in 1981–2010 to 28% at 1.5 °C and 92% at 4 °C, of an agricultural drought increases from 9 to 24% at 1.5 °C and 61% at 4 °C, and of the 50-year return period river flood increases from 2 to 2.4% at 1.5 °C and 5.4% at 4 °C. The chance of a damaging hot spell for maize increases from 5 to 50% at 4 °C, whilst the chance for rice rises from 27 to 46%. There is considerable uncertainty around these central estimates, and impacts and risks vary between regions. Some impacts—for example heatwaves—increase rapidly as temperature increases, whilst others show more linear responses. The paper presents estimates of the risk of impacts exceeding specific targets and demonstrates that these estimates are sensitive to the thresholds used. [ABSTRACT FROM AUTHOR]

This paper provides an assessment of Article 4.1 of the Paris Agreement on climate; the main goal of which is to provide guidance on how “to achieve the long-term temperature goal set out in Article 2”. Paraphrasing, Article 4.1 says that, to achieve this end, we should decrease greenhouse gas (GHG) emissions so that net anthropogenic GHG emissions fall to zero in the second half of this century. To aggregate net GHG emissions, 100-year global warming potentials (GWP-100) are commonly used to convert non-CO2 emissions to equivalent CO2 emissions. The GWP-scaling method is tested using methane as an example. The temperature projections using GWP-100 scaling are shown to be seriously in error. This throws doubt on the use of GWP-100 scaling to estimate net GHG emissions. An alternative method to determine the net-zero point for GHG emissions based on radiative forcing is derived, where the net-zero point is identified with the maximum of GHG forcing. This shows that, to meet the Article 2 warming goal, the net-zero point for GHG emissions needs to be reached as early as 2036, much sooner than in the Article 4.1 window. Other scientific problems in Article 4.1 that further undermine its purpose to guide efforts to achieve the Article 2 temperature targets are discussed. [ABSTRACT FROM AUTHOR]

The treatment of uncertainty in climate-change science is dominated by the far-reaching influence of the 'frequentist' tradition in statistics, which interprets uncertainty in terms of sampling statistics and emphasizes p-values and statistical significance. This is the normative standard in the journals where most climate-change science is published. Yet a sampling distribution is not always meaningful (there is only one planet Earth). Moreover, scientific statements about climate change are hypotheses, and the frequentist tradition has no way of expressing the uncertainty of a hypothesis. As a result, in climate-change science, there is generally a disconnect between physical reasoning and statistical practice. This paper explores how the frequentist statistical methods used in climate-change science can be embedded within the more general framework of probability theory, which is based on very simple logical principles. In this way, the physical reasoning represented in scientific hypotheses, which underpins climate-change science, can be brought into statistical practice in a transparent and logically rigorous way. The principles are illustrated through three examples of controversial scientific topics: the alleged global warming hiatus, Arctic-midlatitude linkages, and extreme event attribution. These examples show how the principles can be applied, in order to develop better scientific practice. "La théorie des probabilités n'est que le bon sens reduit au calcul." (Pierre-Simon Laplace, Essai Philosophiques sur les Probabilités, 1819). "It is sometimes considered a paradox that the answer depends not only on the observations but on the question; it should be a platitude." (Harold Jeffreys, Theory of Probability, 1st edition, 1939). [ABSTRACT FROM AUTHOR]

The fact of a carbon budget given commitment to limiting global-mean temperature increase to below 2 °C warming relative to pre-industrial levels makes CO2 emissions a scarce resource. This fact has significant consequences for the ethics of climate change. The paper highlights some of these consequences with respect to (a) applying principles of distributive justice to the allocation of rights to emissions and the costs of mitigation and adaptation, (b) compensation for the harms and risks of climate change, (c) radical new ideas about a place for criminal justice in tackling climate change, and (d) catastrophe ethics. [ABSTRACT FROM AUTHOR]

As climate change continues to alter local weather patterns, it is important to understand how people are experiencing such changes because personal experience may affect mitigation and adaptation policy preferences and behaviors. Local weather conditions are also an easily accessible source of information that, aggregated over time, may enable people to detect long-term climate trends and update their beliefs about global warming. However, motivated reasoning—the tendency to fit information to conclusions that correspond with a preexisting belief—may limit the accuracy of local weather perceptions. This paper focuses on perceptions of seasonal weather in Norway and examines evidence for motivated reasoning consistent with pre-existing beliefs about climate change, using a national panel survey combined with high-resolution seasonal climate observations. Respondents’ perceptions are sensitive to observed differences in both temperature and precipitation, but respondents are more likely to accurately perceive local precipitation than local temperature. Controlling for observed conditions, beliefs about global climate change had a large effect on perceptions of seasonal temperature, and smaller effects on perceptions of seasonal precipitation. These findings provide evidence that individual perceptions of seasonal weather are related to local conditions, but they are also likely to be motivated by beliefs about global climate change. [ABSTRACT FROM AUTHOR]

While climate change is projected to increase displacement of people, knowledge on this issue remains limited and fragmented. In his paper we focus on the micro-level and study the effects of individual perceptions of different types of environmental events (i.e., sudden/short-term vs. slow-onset/long-term) on migration decisions. Our results based on newly collected micro-level survey data from Vietnam shows that while slow-onset environmental events, such as droughs, significantly decrease the likelihood of migration, short-term events, such as floods, are positively related to migration, although not in a statistically significant way. When contrasting individual level perceptions with actual climatic events we observe that migrants and non-migrants perceive both long-term as well as sudden-onset environmental events in different ways. While non-migrants are slightly better in judging the actual extremeness of events such as floods and hurricanes, it is the migrants who are slightly better in judging the actual extremeness in the case of droughts. [ABSTRACT FROM AUTHOR]

How climate change might impact energy demand is not well understood, yet energy forecasting requires that assumptions be specified. This paper reviews the literature on the relationship between global warming and the demand for space cooling in buildings. It then estimates two key parameters that link energy for space cooling to cooling degree days (CDDs) using data for nine U.S. Census divisions, which is the spatial resolution of the National Energy Modeling System (NEMS). The first parameter is the set point temperature for calculating CDDs; the second is the exponent for representing the relationship between changes in CDDs and changes in electricity consumption for space cooling. We find that the best-fitting CDDs have a set point of 67 °F (19.4 °C), for both residential and commercial buildings, rather than the conventional 65 °F (18.3 °C). Set points also vary by region, with warmer regions tending to have higher set points. When CDDs are based on the conventional set point, the best fitting exponent is 1.5 for both residential and commercial buildings, indicating that space cooling is more climate-sensitive than is specified in NEMS. As a result, the official projections of U.S. energy consumption would appear to underestimate the energy required for space cooling. [ABSTRACT FROM AUTHOR]

This study explores sense-making about climate engineering among lay focus group participants in Japan, New Zealand, the USA and Sweden. In total, 23 qualitative focus group interviews of 136 participants were conducted. The analyses considered sense-making strategies and heuristics among the focus group participants and identified commonalities and variations in the data, exploring participants' initial and spontaneous reactions to climate engineering and to several recurrent arguments that feature in scientific and public debate (e.g. climate emergency). We found that, despite this study's wide geographical scope, heterogeneous focus group compositions, and the use of different moderators, common themes emerged. Participants made sense of climate engineering in similar ways, for example, through context-dependent analogies and metaphorical descriptions. With few exceptions, participants largely expressed negative views of large-scale deliberate intervention in climate systems as a means to address anthropogenic global warming. [ABSTRACT FROM AUTHOR]

High impact weather events such as extreme temperatures or rainfall can cause significant disruption across the UK affecting sectors such as health, transport, agriculture and energy. In this study we draw on the latest set of UK climate projections, UKCP, to examine metrics relating to high-impact weather over the UK and how these change with different levels of future global warming from 1.5 °C to 4 °C above pre-industrial. The changes to these hazards show increases in the frequency of extremely hot days and nights, with a UK average increase in hot days of between 5 and 39 days per year between 1.5 °C and 4 °C of global warming. Projections indicate an increase in cooling degree days of 134–627% and an increase in growing degree days of 19–60% between 1.5 °C and 4 °C of global warming. Extremely hot nights, which are currently rare, are emerging as more common occurrences. The frequency of high daily temperatures and rainfall increase systematically, while the frequency of very cold conditions (based on days where temperatures fall below 0 °C) is shown to decrease by 10 to 49 days per year. A reduction in heating degree days, of 11–32% between 1.5 °C and 4 °C of warming, is projected. Levels of daily rainfall, which currently relate to increased risk of river flooding, are shown to increase across the country, with increases of days with high impact levels of rainfall occurring by 1 to 8 days per year between 1.5 °C and 4 °C of warming. Average drought severity is projected to increase for 3-, 6-, 12- and 36-month-long droughts. The largest changes in the severity of the 12-month drought are between −3 and +19% between 1.5 °C and 4 °C of warming and for 36-month drought between −2 and +54% between 1.5 °C and 4 °C of warming. The projected future changes in high impact weather from this study will enable the characterization of climate risks and ultimately be able to better inform adaptation planning in different sectors to support the increase in resilience of the UK to future climate variability and change. [ABSTRACT FROM AUTHOR]

While the US Congress has repeatedly failed to pass the national legislation to address climate change over the years, there has been much more progress among state and local governments. Is this progress on climate change policy at the subnational level merely a reflection of the dominance of the Democratic Party in certain regions of the country, or does it reflect successful bipartisan action? In this essay, we present novel evidence from two surveys of subnational policymakers, conducted in 2015 and 2017, to demonstrate that there is widespread bipartisan agreement among Republican and Democrat policymakers at the subnational level about (1) the existence of global warming and (2) what to do about it. Specifically, a majority in both parties believe global warming is happening and support the use of renewable energy mandates—rather than cap-and-trade, carbon tax, or emissions standards—to address the problem. [ABSTRACT FROM AUTHOR]

The overlap in sources of greenhouse gas and local air pollutant emissions creates scope for policy measures to limit global warming and improve air quality simultaneously. In a first step, we derive estimates for the air pollution mortality-related component of the social cost of atmospheric release for 6 pollutants and 56 regions in the world. Combining these estimates with emission inventory data highlights that sector contributions to greenhouse gas emissions and air pollution health impacts differ widely across regions. Next, simulations of future emission pathways consistent with the 2 °C and 1.5 °C targets illustrate that strengthening climate policy ambition raises the total value of air quality co-benefits despite lower marginal co-benefits per tonne of greenhouse gas emissions abated. Finally, we use results from a multi-model ensemble to quantify and compare the value of health-related ambient air quality co-benefits of climate policy across sectors and regions. On the global level, overall air quality co-benefits range from $8 to $40 per tonne of greenhouse gases abated in 2030, with median across models and scenarios of $18/tCO2e. These results mask strong differentiation across regions and sectors, with median co-benefits from mitigation in the residential and service sectors in India exceeding $500/tCO2e. By taking a sector- and region-specific perspective, the results presented here reveal promising channels to improve human health outcomes and to ratchet up greenhouse gas reduction efforts to bridge the gap between countries' pledges and the global targets of the Paris Agreement. [ABSTRACT FROM AUTHOR]

Current-climate precipitation and temperature extremes have been identified by decision makers in West Africa as among the more impactful weather events causing lasting socioeconomic damage. In this article, we use a plausible future-climate scenario (RCP8.5) for the end of the twenty-first century to explore the relative commonness of such extremes under global warming. The analysis presented considers what a typical day in the future climate will feel like relative to current extrema. Across much of West Africa, we see that the typical future-climate day has maximum and minimum temperatures greater than 99.5% of currently experienced values. This finding exists for most months but is particularly pronounced during the Boreal spring and summer. The typical future precipitation event has a daily rainfall rate greater than 95% of current storms. These findings exist in both a future scenario model run with and without parameterised convection, and for many of the Coupled Model Inter-comparison Project version 5 ensemble members. Additionally, agronomic monsoon onset is projected to occur later and have greater inter-annual variability in the future. Our findings suggest far more extreme conditions in future climate over West Africa. The projected changes in temperature and precipitation could have serious socioeconomic implications, stressing the need for effective mitigation given the potential lack of adaptation pathways available to decision makers. [ABSTRACT FROM AUTHOR]

For centuries, traditional high-altitude oases in Oman have depended on the cultivation of deciduous fruit trees. This study explores the effects of climate change on winter chill (estimated as Chilling Hours—CH and Chill Portions—CP), a prerequisite to overcoming dormancy and initiating flowering, in three Omani oases. The results are compared with findings from an earlier study which reported a decrease in the numbers of CH in high-elevation oases by an average of 1.2–9.5 CH year−1 between 1983 and 2008. Location-specific weather data were obtained by merging 15 years of in situ recordings with 28 years of observations from an official weather station near the top of the investigated watershed. Between 1991 and 2018, scenarios of the past few decades show chill reductions by 75, 35 and 18% when estimated in CP at the oases of Masayrat ar Ruwajah (1030 m a.s.l.), Qasha' (1640 m a.s.l.), and Al 'Ayn (1900 m a.s.l.), respectively. Over the course of the twenty-first century, the lowest-elevation oasis at Masayrat ar Ruwajah is projected to lose virtually all winter chill, whereas, despite significant chill losses, conditions are expected to remain viable for some of the currently grown species in the higher-elevation oases. These projected changes will compromise the cultivation of temperate fruit trees in the near future, affecting the sustainability of Omani oases. Our methods support results from earlier work performed at these locations and provide an updated procedure for assessing climate change effects on temperature-dependent systems. [ABSTRACT FROM AUTHOR]

Since global warming between 2 and 4.9 °C by 2100 is unlikely to be avoided, humans will have to live with and adapt to the impacts of climate change. Migration has long been touted as a strategy for adapting to climate change, but there is limited understanding of which aspects of climate change will have greatest influence on peoples' decision to move somewhere they consider safer or stay somewhere safe. Here, we present results from two online surveys about mobility decisions from one low (Philippines) and one high (Australia) income country within the Asia-Pacific region with similar vulnerabilities to natural hazards. Online surveys with about 1100 respondents each were conducted in both countries. Results showed that natural hazards played a strong role in the mix of reasons for mobility, particularly in the Philippines. Sudden onset hazards had the greatest influence. Results of ordered probit models showed that the perception of personal damage from hazards was strongly positively associated with mobility decisions of respondents in both countries. Mobility decisions of people in Australia were further influenced by their experience with the specific hazards: those with greater experience of slow onset hazards were more likely, and those who had experience with sudden hazards less likely, to consider these when moving or staying somewhere. People in Australia might only react to sudden onset hazards with temporary relocation since experience had shown that they can adapt to them. This suggests that slow onset climate change related impacts such as heat waves and sea level rise, as well as environmental degradation and pollution, may have more sustained effects on long-term mobility than sudden events. In the Philippines, personal characteristics such as gender, income, and health had the greatest impact while experience with hazards had almost none. [ABSTRACT FROM AUTHOR]

The uncertainty language framework used by the Intergovernmental Panel on Climate Change (IPCC) is designed to encourage the consistent characterization and communication of uncertainty between chapters, working groups, and reports. However, the framework has not been updated since 2010, despite criticism that it was applied inconsistently in the Fifth Assessment Report (AR5) and that the distinctions between the framework's three language scales remain unclear. This article presents a mixed-methods analysis of the application and underlying interpretation of the uncertainty language framework by IPCC authors in the three special reports published since AR5. First, I present an analysis of uncertainty language term usage in three recent special reports: Global Warming of 1.5°C (SR15), Climate Change and Land (SRCCL), and The Ocean and Cryosphere in a Changing Climate (SROCC). The language usage analysis highlights how many of the trends identified in previous reports—like the significant increase in the use of confidence terms—have carried forward into the special reports. These observed trends, along with ongoing debates in the literature on how to interpret the framework's three language scales, inform an analysis of IPCC author experiences interpreting and implementing the framework. This discussion is informed by interviews with IPCC authors. Lastly, I propose several recommendations for clarifying the IPCC uncertainty language framework to address persistent sources of confusion highlighted by the authors. [ABSTRACT FROM AUTHOR]

Global warming will disproportionately affect people of color (e.g., Latinos). Previous research has found that Latinos in the USA are more engaged with global warming than are non-Latino Whites, in part, because they are more likely to perceive it as a serious risk. It was unclear, however, what factors most strongly explain Latinos' elevated perceptions of risk. This study uses two parallel, nationally representative surveys of Latino and non-Latino White Americans to investigate these different levels of risk perception. Mediation analyses indicate that Latinos' greater risk perceptions may be explained by (in order of magnitude) their stronger pro-climate injunctive social norms and egalitarian worldviews, stronger identification with the Democratic party, more frequent communication with family outside the USA, greater harm from environmental hazards, stronger descriptive norms, and a weaker individualist worldview. These findings help inform strategies for communicating with different subgroups of Americans that have different global warming risk perceptions. [ABSTRACT FROM AUTHOR]

We assess uncertainties in projecting future changes in extreme storm surge height (SSH) based on typhoon data extracted from ensemble experiment results with four sea surface temperature (SST) conditions and three global warming scenarios using a single atmospheric global climate model. In particular, this study focus on typhoons passing around the Korean Peninsula (KP) defined as the region of 32 to 40° N and 122 to 132° E. It is predicted the number of the typhoons affecting the KP will decrease by 4~73% while their strength will increase by 0.8~1.4% under the given future conditions. The locations of genesis and lysis of the typhoons are expected to be shifted towards the northwest and northeast for all ensemble experiment conditions, respectively. However, the extent of their change varies depending on the future SST and global warming conditions. Storm surge simulations were carried out by using predicted typhoon data as an external force. It is found that future SST patterns and climate warming scenarios affect future typhoon characteristics, which influences values of extreme SSH and locations of the vulnerable area to storm surge under the future climate conditions. In particular, the values of extreme SSH and the locations of the vulnerable area to storm surge appear to be strongly influenced by both pathway and frequency of intense typhoons. [ABSTRACT FROM AUTHOR]

East-Central Asia is one of the most vulnerable and sensitive regions to climate change, and the variability of extreme precipitation attracts great attention due to the large population and the importance of its economy. Here, three special runs with the Community Earth System Model (CESM) are used to project the changes in representative extreme precipitation indices (Rx1day, Rx5day, R95p, SDII) over East-Central Asia under the 1.5 °C and 2 °C Paris Agreement limits. The results indicate that Rx1day and Rx5day will increase by 28% and 15%, respectively, under the 1.5 °C warming level relative to the historical period (1971–2000). Most areas over East-Central Asia are projected to experience an accelerated increase in response to a further 0.5 °C warming. Specifically, humid areas (HAs) are projected to experience a greater increase in R95p annual days and area fraction, whereas arid and semiarid areas (ASAs) may have threefold higher risks. The proportion of extreme precipitation in total will increase ~10% in most HAs in response to the 0.5 °C additional warming. Holding global warming at 1.5 °C instead of 2 °C reduces the occurrence of R95p annual days by ~3 days/year in humid areas and ~1 day/year in ASAs. For SDII, most HAs will experience 0.2–0.6 mm/day and 0.2–0.4 mm/day increases in 1.5 °C or 2 °C warming limits, especially in Southeast China and the Himalayas. Therefore, limiting global warming to under 1.5 °C is beneficial to reducing the occurrence and associated impact of precipitation extremes in East-Central Asia. [ABSTRACT FROM AUTHOR]

Grazing systems emit greenhouse gases, which can, under specific agro-ecological conditions, be partly or entirely offset by soil carbon sequestration. However, any sequestration is time-limited, reversible, and at a global level outweighed by emissions from grazing systems. Thus, grazing systems are globally a net contributor to climate change and the time scale of key processes needs to be factored into any mitigation efforts. Failing to do so leads to unrealistic expectations of soil carbon management in grazing systems as a mitigation strategy. Protecting the large carbon stocks in grazing lands is also essential in order to avoid further climate change from additional CO2 release. Despite the time-limited and reversible nature of soil carbon sequestration in grazing lands, sequestration should be promoted in cases where it delivers environmental and agronomic benefits as well as for its potential, particularly on degraded land, to increase the feasibility of limiting global warming to less than 2 or preferably 1.5 °C. Some peer-reviewed sequestration estimates are of a similar order of magnitude to other food systems mitigation options over a 10–20 years period, such as reducing food loss and waste by 15% or aligning diets with current health related dietary-recommendations. However, caution should be applied to such comparisons since mitigation estimates are associated with large uncertainties and will ultimately depend on the economic cost-benefit relation, feasibility of implementation and time frame considered. [ABSTRACT FROM AUTHOR]

Guided by the Paris Agreement, the IPCC Special Report on Global Warming of 1.5 °C reported potential risks of climate change at different global warming levels (GWLs). To provide fundamental information on future temperature extremes over Southeast Asia (SEA), projected changes in temperature extreme indices are evaluated for different seasons at 1.5 °C and 2 °C GWLs against the historical reference period of 1976–2005 based on the ensemble of CORDEX simulations. Results show that the temperature indices increase significantly across the Indochina Peninsula and Maritime Continent at both GWLs except for decreasing daily temperature range (DTR) in the dry season, with more pronounced magnitudes at 2 °C GWL. Moreover, the regionally averaged ensemble medians of the indices show various changes over different subregions. At 1.5 °C and 2 °C GWLs, most pronounced increases of threshold indices. i.e. summer days (SU) and tropical nights (TR), are projected in Sumatra and Sulawesi for both wet and dry seasons. The warm spell duration (WSDI) increases generally, with strongest magnitudes for Sumatra and Sulawesi (Philippines and Sulawesi) in the wet (dry) season. On the other hand, significant increases of warm days and nights can also be observed at 2 °C GWL compared to 1.5 °C, particularly in the dry season, suggesting the high sensitivity of temperature extremes over the SEA. The projected potentially conspicuous temperature extremes under global warming of 1.5 °C and 2 °C primarily concentrate on the densely populated coastal regions of the main islands, showing the necessity of restricting global warming to 1.5 °C aiming at the eradication and reduction of regional climate stress for the human system in the developing countries over the SEA. [ABSTRACT FROM AUTHOR]

Global warming is expected to increase droughts and heatwaves, and consequently fire danger in southern Europe in the forthcoming decades. However, an assessment of the uncertainties associated with this general trend at regional scales, relevant to decision-making, is still missing. This study aims at assessing potential climate change impacts on fire danger over France through the projection of the widely used Fire Weather Index (FWI) and at quantifying the different sources of climate-driven uncertainty associated with these projections. We used daily climate experiments covering the 1995–2098 period under two scenarios (RCP4.5 and RCP8.5) provided by the EURO-CORDEX initiative. Our results show an overall increase in FWI throughout the century, with the largest absolute increases in the Mediterranean area. Model uncertainty was very high in western France, previously identified as a potential fire-prone region under future climate. In contrast, large increases in FWI in the Mediterranean area showed low uncertainty across models. Besides, analyzing the natural variability of FWI revealed that extreme years under present-day climate could become much more frequent by the end of the century. The FWI is projected to emerge from the background of natural variability by mid-twenty-first century with a summer elevated fire danger three times more likely when summer temperature anomaly exceeds + 2 °C. [ABSTRACT FROM AUTHOR]

This article statistically evaluates the extent of climate change and variability in the Sahelian countries since 1901. We perform a statistical analysis based on a linear regression model estimated by ordinary least squares (OLS) and on a structural change model estimated at two different scales (countries and agroecological zones) for temperature and precipitation. CRU is the main source of our data but obtained through two different websites. The first database from the World Bank provides temperature and precipitation data from 1901 to 2012 and are provided at the country level. The analysis of agroecological zones is based on an original database from 1901 to 2016 constructed with data available on the website of the Royal Netherlands Institute of Meteorology. The results suggest that climate change has indeed started in all the countries of the Sahel with 1980 being a turning point of global warming. They also suggest that agroecological zones are experiencing climate change and variability, with turning points in 1940 and 1980. Desert and arid areas have experienced a large number of breaks from 1901 to 2016 while in Nigeria, wetlands and non-desert areas experienced several breaks. [ABSTRACT FROM AUTHOR]

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of "niche and emerging findings", e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals. [ABSTRACT FROM AUTHOR]

Global warming is caused mainly by CO2 emission from burning fossil fuels and is beginning to have large negative impacts on human well-being and ecosystems (IPCC 2014; IPCC 2018). Policies that mitigate CO2 emissions will require public support. Here, we examine how support for several possible decarbonization policies varies as a function of the personal carbon footprint of a researcher who advocates the policy. We find that people are more likely to support policies if the advocate for these policies has a low carbon footprint. Replicating our prior work, we find that the communicators' carbon footprint massively affect their credibility and intentions of their audience to conserve energy (Attari, Krantz and Weber 2016). Our new finding is that their carbon footprint also affects audience support for public policies advocated by the communicator. In a second study, we show that the negative effects of a large carbon footprint on credibility are greatly reduced if the communicator reforms their behavior by reducing their personal carbon footprints. The implications of these results are stark: effective communication of climate science and advocacy of both individual behavior change and public policy interventions are greatly helped when advocates lead the way by reducing their own carbon footprint. [ABSTRACT FROM AUTHOR]

One of the biggest challenges to sustainability is lack of public support for policies needed to reduce greenhouse gas emissions. Across three studies, we explored how solution framing impacts public support for financially costly policies designed to reduce greenhouse gas emissions. Study 1 analyzed data from a statewide public opinion poll (N = 771), while studies 2 (N = 100) and 3 (N = 163) were laboratory-based experiments. Specifically, we found that polling questions that asked about a financially costly climate change policy received more support when the goal of the policy was to create efficient technologies than when the goal was to curtail behavior. In addition, we replicate previous research showing that there is a partisan gap for beliefs about global warming and extend this research to show that the partisan gap is not found when looking at support for solutions. The implications of these results for promoting needed climate change policies is discussed. [ABSTRACT FROM AUTHOR]

Research on climate change media coverage is growing. Few studies, however, have investigated how the media portrays climate change impacts on human health. This review, therefore, presents a quantitative spatiotemporal analysis of Canadian newspaper coverage of climate change impacts on health between 2005 and 2015. Using the ProQuest® and Eureka® databases, a multiphase systematic review strategy was employed to identify relevant English and French articles from two national and six regional high-circulation newspapers. Quantitative and qualitative data were extracted from 145 articles and analyzed to characterize the range, extent, and nature of climate-health newspaper coverage in Canada and to compare these characteristics by region and over time. Coverage varied by region, with the highest proportion of climate-health coverage in Northern Territories (Yukon, Northwest Territories, Nunavut). Over time, there was a decreasing publication frequency trend. Almost all articles described negative climate change impacts on health, with a predominant focus on infectious and chronic noninfectious diseases; however, less than half of the articles discussed climate change solutions. These trends suggest that current media coverage might not drive widespread public support for policies and actions needed to protect against projected climate-health risks. Consequently, as climate change continues to challenge human health, increasing media emphasis on climate change impacts on human health, as well as a shift toward enabling and empowering climate change communication, in which viable mitigation and adaptation options are emphasized, could help to spur action to reduce climate change health risks. [ABSTRACT FROM AUTHOR]

Survey researchers often treat self-assessed understanding of climate change as a rough proxy for knowledge, which might affect what people believe about this topic. Self-assessments can be unrealistically high, however, and correlated with politics, so they deserve study in their own right. Turning the usual perspective around to view self-assessed understanding as dependent variable, problematically related to actual knowledge, casts self-assessments in a new light. Analysis of a 2016 US survey that carried a five-item test of very basic, belief-neutral but climate-relevant knowledge (such as knowing about the location of North and South Poles) finds that, at any given level of knowledge, people saying they “understand a great deal” about climate change are more likely to be older, college-educated, and male. Self-assessed understanding exhibits a U-shaped political pattern: highest among liberals and the most conservative, but lowest among moderate conservatives. Among liberal and middle-of-the-road respondents, self-assessed understanding of climate change is positively related to knowledge. Among the most conservative, however, understanding is unrelated or even negatively related to knowledge. For that group in particular, high self-assessed understanding reflects confidence in political views, rather than knowledge about the physical world. [ABSTRACT FROM AUTHOR]

Summer tourism is one of the most important contributors to the European GDP especially for the southern countries and is highly dependent on the climatic conditions. Changes in average climatic conditions, along with the potential subsequent changes in the physical environment, will pose stress on the favorability of the climate of European destinations for tourism and recreational activities. Here, we study the vulnerability of summer-oriented tourism due to a global temperature increase by 2 °C relative to the preindustrial era. We use a well-defined framework of exposure, sensitivity, and adaptive capacity indicators for a set of plausible climate (RCPs) and socioeconomic (SSPs) combinations. Our result shows that a 2 °C global warming will pose substantial changes to the vulnerability of the European tourism sector. Despite the general increase in exposure, the vulnerability of summer tourism is highly depended on the socioeconomic developments (SSPs). Although exposure is higher for most of the popular southern European destinations like Spain, France, South Italy, southernmost Greece, and Cyprus, they are expected to be less vulnerable than others, under specific SSPs, due to their higher capacity to adapt to a different climate. The capacity to adapt is lower for higher emission scenarios. Substantial changes are also apparent at the subnational level. Countries like France are foreseen to experience very diverse impacts and vulnerabilities within their own territories that will have consequences in terms of domestic tourism. The dynamics of these changes are expected to alter the state of the current European tourism regime. [ABSTRACT FROM AUTHOR]

Science teachers play an important role promoting civic scientific literacy, but recent research suggests they are less effective than they could be in educating the next generation of citizens about climate change and its causes. One particular area of concern is that many science teachers in the USA encourage students to debate settled empirical findings, such as the role of human-generated emissions of greenhouse gases in raising global temperatures. A common reaction is to call for science teachers to receive more formal training in climate science to increase their knowledge, which will then improve teaching. Using a nationally representative survey of 1500 middle school and high school science teachers, we investigate each element in this argument, and show that increased science coursework in college has modest effects on teachers’ content knowledge and on their teaching choices, including decisions about debating “both sides.” We also find that teachers’ personal political orientations play a large role in their teaching strategies: right-leaning teachers devote somewhat less time to global warming and are much more likely to encourage student debate on the causes of global warming. We discuss the implications of these findings and argue teacher education might be more effective if informed by insights from the emerging discipline of science communication. However, although knowledge and ideology are predictive of pedagogy, a large number of teachers of all ideological positions and all levels of subject expertise encourage students to debate established findings. We discuss this and highlight potential explanations. [ABSTRACT FROM AUTHOR]

How climate-sensitive actors—like commercial farmers—perceive, understand, and react to weather and climate stimuli will ultimately determine the success or failure of climate change adaptation policies. Many studies have characterized farmers’ climate risk perceptions or farming practices, but few have evaluated the in situ decision-making processes that link (or fail to link) risk perceptions to adaptive behaviors. Here, we use a novel methodology to reveal patterns in climate-sensitive decision-making by commercial grain farmers in South Africa. We structure, linguistically code, and statistically analyze causal relationships described in 30 mental models interviews. We show that farmers’ framing of weather and climate risks strongly predicts their adoption of conservation agriculture (CA)—climate-resilient best practices that reduce shorter-term financial and weather risks and longer-term agronomic risks. These farmers describe weather and climate risks using six exhaustive and mutually exclusive languages: agricultural, cognitive, economic, emotional, political, and survival. The prevalence of agricultural and economic language only weakly predicts CA practice, whereas emotional and farm survival language strongly limits CA adoption. The framing of weather risks in terms of farm survival impedes adaptations that are likely to improve such survival in the longer term. But this survival framing is not necessarily indicative of farmers’ current economic circumstances. It represents a consequential mindset rather than a financial state and it may go undetected in more conventional studies relying on direct survey or interview questions. [ABSTRACT FROM AUTHOR]

Many areas of the natural and social sciences involve complex systems that link together multiple sectors. Integrated assessment models (IAMs) are approaches that integrate knowledge from two or more domains into a single framework, and these are particularly important for climate change. One of the earliest IAMs for climate change was the DICE/RICE family of models, first published in Nordhaus (Science 258:1315-1319, 1992a), with the latest version in Nordhaus (2017, 2018). A difficulty in assessing IAMs is the inability to use standard statistical tests because of the lack of a probabilistic structure. In the absence of statistical tests, the present study examines the extent of revisions of the DICE model over its quarter-century history. The study finds that the major revisions have come primarily from the economic aspects of the model, whereas the environmental changes have been much smaller. Particularly, sharp revisions have occurred for global output, damages, and the social cost of carbon. These results indicate that the economic projections are the least precise parts of IAMs and deserve much greater study than has been the case up to now, especially careful studies of long-run economic growth (to 2100 and beyond). Additionally, the approach developed here can serve as a useful template for IAMs to describe their salient characteristics and revisions for the broader community of analysts. [ABSTRACT FROM AUTHOR]

This study evaluates regional-scale projections of climate indices that are relevant to climate change impacts in Canada. We consider indices of relevance to different sectors including those that describe heat conditions for different crop types, temperature threshold exceedances relevant for human beings and ecological ecosystems such as the number of days temperatures are above certain thresholds, utility relevant indices that indicate levels of energy demand for cooling or heating, and indices that represent precipitation conditions. Results are based on an ensemble of high-resolution statistically downscaled climate change projections from 24 global climate models (GCMs) under the RCP2.6, RCP4.5, and RCP8.5 emissions scenarios. The statistical downscaling approach includes a bias-correction procedure, resulting in more realistic indices than those computed from the original GCM data. We find that the level of projected changes in the indices scales well with the projected increase in the global mean temperature and is insensitive to the emission scenarios. At the global warming level about 2.1 °C above pre-industrial (corresponding to the multi-model ensemble mean for 2031-2050 under the RCP8.5 scenario), there is almost complete model agreement on the sign of projected changes in temperature indices for every region in Canada. This includes projected increases in extreme high temperatures and cooling demand, growing season length, and decrease in heating demand. Models project much larger changes in temperature indices at the higher 4.5 °C global warming level (corresponding to 2081-2100 under the RCP8.5 scenario). Models also project an increase in total precipitation, in the frequency and intensity of precipitation, and in extreme precipitation. Uncertainty is high in precipitation projections, with the result that models do not fully agree on the sign of changes in most regions even at the 4.5 °C global warming level. [ABSTRACT FROM AUTHOR]

Extreme weather events are projected to be more frequent and severe across the globe because of global warming. This poses challenging problems for critical infrastructures, which could be dramatically affected (or disrupted), and may require adaptation plans to the changing climate conditions. The INTACT FP7-European project evaluated the resilience and vulnerability of critical infrastructures to extreme weather events in a climate change scenario. To identify changes in the hazard induced by climate change, appropriate extreme weather indicators (EWIs), as proxies of the main atmospheric features triggering events with high impact on the infrastructures, were defined for a number of case studies and different approaches were analyzed to obtain local climate projections. We considered the influence of weighting and bias correction schemes on the delta approach followed to obtain the resulting projections, considering data from the Euro-CORDEX ensemble of regional future climate scenarios over Europe. The aim is to provide practitioners, decision-makers, and administrators with appropriate methods to obtain actionable and plausible results on local/regional future climate scenarios. Our results show a small sensitivity to the weighting approach and a large sensitivity to bias correcting the future projections. [ABSTRACT FROM AUTHOR]

Climate change is already affecting species and their distributions. Distributional range changes have occurred and are projected to intensify for many widespread plants and animals, creating associated risks to many ecosystems. Here, we estimate the climate change-related risks to the species in globally significant biodiversity conservation areas over a range of climate scenarios, assessing their value as climate refugia. In particular, we quantify the aggregated benefit of countries' emission reduction pledges (Intended Nationally Determined Contributions and Nationally Determined Contributions under the Paris Agreement), and also of further constraining global warming to 2 °C above pre-industrial levels, against an unmitigated scenario of 4.5 °C warming. We also quantify the contribution that can be made by using smart spatial conservation planning to facilitate some levels of autonomous (i.e. natural) adaptation to climate change by dispersal. We find that without mitigation, on average 33% of each conservation area can act as climate refugium (or 18% if species are unable to disperse), whereas if warming is constrained to 2 °C, the average area of climate refuges doubles to 67% of each conservation area (or, without dispersal, more than doubles to 56% of each area). If the country pledges are fulfilled, an intermediate estimate of 47-52% (or 31-38%, without dispersal) is obtained. We conclude that the Nationally Determined Contributions alone have important but limited benefits for biodiversity conservation, with larger benefits accruing if warming is constrained to 2 °C. Greater benefits would result if warming was constrained to well below 2 °C as set out in the Paris Agreement. [ABSTRACT FROM AUTHOR]

This study examines how characteristics of tropical cyclones (TCs) that are explicitly resolved in a global atmospheric model with horizontal resolution of approximately 28 km are projected to change in a warmer climate using bias-corrected sea-surface temperatures (SSTs). The impact of mitigating from RCP8.5 to RCP4.5 is explicitly considered and is compared with uncertainties arising from SST projections. We find a reduction in overall global TC activity as climate warms. This reduction is somewhat less pronounced under RCP4.5 than under RCP8.5. By contrast, the frequency of very intense TCs is projected to increase dramatically in a warmer climate, with most of the increase concentrated in the NW Pacific basin. Extremes of storm related precipitation are also projected to become more common. Reduction in the frequency of extreme precipitation events is possible through mitigation from RCP8.5 to RCP4.5. In general more detailed basin-scale projections of future TC activity are subject to large uncertainties due to uncertainties in future SSTs. In most cases these uncertainties are larger than the effects of mitigating from RCP8.5 to RCP4.5. [ABSTRACT FROM AUTHOR]

Even as US partisan polarization shapes climate and energy attitudes, substantial heterogeneity in climate opinions still exists among both Republicans and Democrats. To date, our understanding of this partisan heterogeneity has been limited to analysis of national- or, less commonly, state-level opinion poll subsamples. However, the dynamics of political representation and issue commitments play out over more finely resolved state and local scales. Here we use previously validated multilevel regression and post-stratification (MRP) models (Howe et al., Nat Clim Chang 5(6):596-603 2015; Mildenberger et al., PLoS One 11(8):e0159774 2016) combined with a novel approach to measuring the distribution of party members to model, for the first time, the spatial distribution of partisan climate and energy opinions. We find substantial geographic variation in Republican climate opinions across states and congressional districts. While Democratic party members consistently think human-caused global warming is happening and support climate policy reforms, the intensity of their climate beliefs also varies spatially at state and local scales. These results have policy-relevant implications for the trajectory of US climate policy reforms. [ABSTRACT FROM AUTHOR]

How drought may change in the future are of great concern as global warming continues. In Part I of this study, we examine the uncertainties in estimating recent drought changes. Substantial uncertainties arise in the calculated Palmer Drought Severity Index (PDSI) with Penman-Monteith potential evapotranspiraiton (PDSI_pm) due to different choices of forcing data (especially for precipitation, solar radiation and wind speed) and the calibration period. After detailed analyses, we recommend using the Global Precipitation Climatology Centre (GPCC) or the Global Precipitation Climatology (GPCP) datasets over other existing land precipitation products due to poor data coverage in the other datasets since the 1990s. We also recommend not to include the years after 1980 in the PDSI calibration period to avoid including the anthropogenic climate change as part of the natural variability used for calibration. Consistent with reported declines in pan evaporation, our calculated potential evapotranspiration (PET) shows negative or small trends since 1950 over the United States, China, and other regions, and no global PET trends from 1950 to 1990. Updated precipitation and streamflow data and the self-calibrated PDSI_pm all show consistent drying during 1950-2012 over most Africa, East and South Asia, southern Europe, eastern Australia, and many parts of the Americas. While these regional drying trends resulted primarily from precipitation changes related to multi-decadal oscillations in Pacific sea surface temperatures, rapid surface warming and associated increases in surface vapor pressure deficit since the 1980s have become an increasingly important cause of widespread drying over land. [ABSTRACT FROM AUTHOR]

While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed state-and-transition simulations, we examined projected trends and tradeoffs for a suite of ecosystem services under four climate change scenarios and two management scenarios (active management emphasizing fuel treatments and no management other than fire suppression) in a fire-prone landscape of dry and moist mixed-conifer forests in central Oregon, USA. Focal ecosystem services included fire potential (regulating service), timber volume (provisioning service), and potential wildlife habitat (supporting service). Projections without climate change suggested active management in dry mixed-conifer forests would create more open forest structures, reduce crown fire potential, and maintain timber stocks, while in moist mixed-conifer forests, active management would reduce crown fire potential but at the expense of timber stocks. When climate change was considered, however, trends in most ecosystem services changed substantially, with large increases in wildfire area predominating broad-scale trends in outputs, regardless of management approach (e.g., strong declines in timber stocks and habitat for closed-forest wildlife species). Active management still had an influence under a changing climate, but as a moderator of the strong climate-driven trends rather than being a principal driver of ecosystem service outputs. These results suggest projections of future ecosystem services that do not consider climate change may result in unrealistic expectations of benefits. [ABSTRACT FROM AUTHOR]

In recent years among the scientific community, adverse effects of climate change shifted from being a hypothesis to being a reality. Coastal Karnataka prioritized climate variability as a productivity-reducing factor in agriculture and fishery farming. Prevailing unsatisfactory productive services in the agricultural sector and allied industries resulted in degradation of natural resources at the farm level. The adverse impact of climate change and continued fragmentation of landholding have led to poor socio-economic status leading to high dependency on farm income and productivity. The present study is focusing on understanding the response of farmers on decision-making and economic performance due to climate change through face-to-face interviews. The decision ability of the farmers was significantly better among high-crisis management groups than small and marginal farmers, who are having highly diverse decision-making ability. Consequently, economic performance, the benefit/cost ratio of high crisis management group was greater than that of medium and low crisis management groups. Finally, this research study emphasizes the importance of behavioral responses of the farmers in formulating policies and designing strategies to overcome ill effects of the climate-induced crisis. [ABSTRACT FROM AUTHOR]

The Paris Climate Agreement sets out an aggressive goal of limiting global average warming to well below 2 °C. As a first step, virtually all countries have put forth greenhouse gas emission reduction pledges in the form of nationally determined contributions, or NDCs, for the 2030 timeframe. Our analysis looks beyond the NDCs to explore potential post-2030 regional emissions reduction participation and ambition. For each scenario, we examine the implications for global emissions and long-term temperature. We then evaluate the regional consequences for energy systems and ensuing costs. We conclude by reflecting on the additional global abatement costs of tightening temperature goals. Overall, this study provides a multidimensional characterization of the scale of regional effort supporting climate outcomes, details important to decision-makers as they consider mid-century emissions targets, and long-run climate objectives. [ABSTRACT FROM AUTHOR]

Climate change poses serious threats to the protection and preservation of cultural heritage and resources. Despite a high level of scholarly interest in climate change impacts on natural and socio-economic systems, a comprehensive understanding of the impacts of climate change on cultural heritage and resources across various continents and disciplines is noticeably absent from the literature. To address this gap, we conducted a systematic literature review methodology to identify and characterize the state of knowledge and how the cultural heritage and resources at risk from climate change are being explored globally. Results from 124 reviewed publications show that scholarly interest in the topic is increasing, employs a wide range of research methods, and represents diverse natural and social science disciplines. Despite such increasing and diverse interest in climate change and cultural heritage and resources, the geographic scope of research is limited (predominantly European focused). Additionally, we identified the need for future studies that not only focuses on efficient, sustainable adaptation planning options but also documents if, and how, the implementation of cultural heritage and resources adaptation or preservation is taking place. This systematic literature review can help direct scholarly research in climate change and cultural heritage and resource area. Ultimately, we hope these new directions can influence policy-making for preservation and adaptation of cultural heritage and cultural resources globally. [ABSTRACT FROM AUTHOR]

While ecosystems-based adaptation (EbA) has been received with great interest, the requirements for EbA implementation and its precise benefits under future climate change are unclear. Furthermore, EbA's overlap with environmental, and development policy agendas leads to ambiguity regarding what actions fall under the rubric of EbA. We analyze the projects identified by the UNFCCC as examples of EbA to understand how EbA is conceptualized and promoted by the international community. Addressing climate change is the primary objective of 58% of the EbA projects; the other 42% of projects provide adaptation benefits yet are not primarily driven by climate change. A project's adaptation targeting is tied to its information needs. Projects whose primary objective is to address climate change are more likely to use detailed climate projections than projects whose primary objective is to address natural hazards, development or ecosystems degradation. A majority of projects do not address uncertainty in future climate change or in adaptation benefits, nor do they track adaptation outcomes. This prevalent lack of monitoring highlights the possibility of a gap between expected and realized adaptation outcomes. It also represents a lost opportunity for improving knowledge of the thresholds of effectiveness of EbA and of factors influencing EbA efficacy. [ABSTRACT FROM AUTHOR]

El Niño, the Indian Ocean Dipole (IOD), and the Tropical North Atlantic variability (TNA) can influence southeastern South America (SESA) rainfall, particularly during springtime. A recent study has shown that during the last century, there were two synchronization periods (1930s and 1970s) in which different tropical oceans interacted among themselves and, in turn, induced precipitation anomalies over SESA. In this study, we evaluate how this collective influence of the tropical oceans on SESA precipitation observed during the twentieth century, can change in the next century as result of anthropogenic forcing. To do so, we use the output of seven different CMIP5 models and construct a network using as nodes the indices of the Niño3.4, the TNA, the IOD and rainfall over SESA. After evaluating their skill in representing the observed network statistics during the twentieth century, we study changes in the network under RCP4.5 and 8.5 global warming scenarios in the twenty-first century. Focusing on the grand CMIP5 ensemble mean, results suggest that an anthropogenic forcing would increase the number of synchronization periods per century, their time length, and the connectivity between nodes (with the exception of TNA and IOD in RCP8.5). The stronger connectivity of SESA precipitation with the tropical oceans in both scenarios suggest an increase of the oceanic influence on rainfall over SESA as a result of anthropogenic forcing, which would enhance its seasonal predictability. However, these results have to be taken with caution because there is a large disparity in model behavior and thus a large uncertainty in conclusions suggested from the grand ensemble mean. [ABSTRACT FROM AUTHOR]

The assumption of a linear relationship between temperature and phenophases may be misleading. Furthermore, a lack of understanding of the changes in temperature sensitivity of phenophases to changes in temperature strongly limits our ability to predict phenological change in response to climate change. We investigated the timing of seven phenophases of six alpine plant species to test the hypothesis of nonlinear responses in their temperature sensitivities to warming and cooling, using a reciprocal transplant experiment along a 3200-3800 m mountain slope gradient. Our results supported our hypothesis and showed that there were different thresholds in temperature sensitivity of phenophases to warming and cooling. Moreover, linear temperature sensitivity models significantly underestimated advances and delays of phenophases within the thresholds of temperature change. The nonlinear temperature sensitivity of phenophases is best explained by plastic and adaptive responses of phenophases to temperature change gradients. Therefore, our results suggest that the thresholds of temperature sensitivity for different species should be determined and that nonlinear models of temperature sensitivity may be essential to predict accurately phenological responses to climate change. [ABSTRACT FROM AUTHOR]

Empirical statistical downscaling (ESD) methods seek to refine global climate model (GCM) outputs via processes that glean information from a combination of observations and GCM simulations. They aim to create value-added climate projections by reducing biases and adding finer spatial detail. Analysis techniques, such as cross-validation, allow assessments of how well ESD methods meet these goals during observational periods. However, the extent to which an ESD method's skill might differ when applied to future climate projections cannot be assessed readily in the same manner. Here we present a 'perfect model' experimental design that quantifies aspects of ESD method performance for both historical and late 21st century time periods. The experimental design tests a key stationarity assumption inherent to ESD methods - namely, that ESD performance when applied to future projections is similar to that during the observational training period. Case study results employing a single ESD method (an Asynchronous Regional Regression Model variant) and climate variable (daily maximum temperature) demonstrate that violations of the stationarity assumption can vary geographically, seasonally, and with the amount of projected climate change. For the ESD method tested, the greatest challenges in downscaling daily maximum temperature projections are revealed to occur along coasts, in summer, and under conditions of greater projected warming. We conclude with a discussion of the potential use and expansion of the perfect model experimental design, both to inform the development of improved ESD methods and to provide guidance on the use of ESD products in climate impacts analyses and decision-support applications. [ABSTRACT FROM AUTHOR]