Enteric fermentation and ruminant eructation: the role (and control?) of methane in the climate change debate

Anthropogenic processes are responsible for between 55% and 70% of the estimated 600 Tg of methane that is released annually into the atmosphere, with enteric fermentation a major contributor to emissions in a number of countries. This paper therefore reviews current levels of CH₄ discharges by both animal type and country, and shows how the growth or decline in national herds over the last 20 years has significantly altered the global composition of enteric emissions. As developing countries are now responsible for almost three-quarters of such emissions, this has important implications in terms of mitigation strategies—particularly as such countries are presently outside the remit of the Kyoto Protocol.     

An increase of early rains in Southern Israel following land-use change?

The October rains (at the onset of the rainy season that extends to April) in southern Israel have steeply increased in the last quarter century relative to the prior two decades. A less pronounced, but appreciable, increase is noted for the rest of the rainy season. This apparent reversal of desertification is attributed here to land use changes. Afforestation, increased cultivation and limitations on grazing after the establishment of the State of Israel resulted in an increased vegetation cover over the inherently high-albedo soils in this region (an area of 10⁴ km²). The changes are shown in a July 1985 Landsat image of the area.The increase in precipitation is specifically attributed to intensification of the dynamical processes of convection and advection resulting from plant-induced enhancement of thedaytime sensible heat flux from the generally dry surface. This enhancement results both from the reduced surface albedo and the reduced soil heat flux (reduced day-to-night heat storage in the soil) in October when insolation is strong. Stronger daytime convection can lead to penetration of the inversions capping the planetary boundary layer (which are weaker in October than in summer) while strengthened advection (sea breeze) can provide moist air from the warm Mediterranean Sea. This suggested mechanism is consistent with previous studies showing that the autumn rains in southern Israel exhibit convective mesoscale characteristics and occur predominantly in the daytime. However, other causes, such as a shift in the synoptic-scale circulation, cannot be ruled out at this stage.     

Impacts of precipitation events and land-use changes on West African river discharges during the years 1951–2000

The aim of this article is to determine the main sources of the variability of large West African river discharges during the years 1951–2000. The analysis is based on river discharge simulations of ORCHIDEE Land-Surface Model forced by NCC (NCEP Corrected by CRU) over this period. In a first part, an analysis of the partitionning of precipitation in the different basins is given. It is first shown that total runoff is more variable and better correlated to precipitation than evapotranspiration over every basin on annual means. Then the more complex link between evapotranspiration and precipitation is investigated through correlation and regression analyses. Over the “dry” (soudano-sahelian) catchments, evapotranspiration is the most variable and mainly correlated to the annual precipitation. Over the “humid” (equatorial) catchment, it is mainly correlated to the season length and does not depend on other characteristics of the precipitation. Over the “intermediate” (guinean) catchments, annual precipitation and season length both play a role, along with the average intensity of rainfall events, and other characteristics such as the number of long breaks in the rainy season. A second part focuses on the way ORCHIDEE reproduces the variability of river discharges for the years 1951–2000. It is shown that relative anomalies are correctly simulated by ORCHIDEE forced by NCC over every catchment without taking into account any land-use change. Moreover, no significant difference is found in the accuracy with which ORCHIDEE simulates the humid (1953–1970) and the dry (1973–1990) periods over two selected catchments. This implies that the impact of land-use changes was much less important than the impact of precipitation changes over the years 1951–2000 in large West African catchments.     

Will climate change impact on wind power development in the UK?

Partly in response to concerns about anthropogenic climate change, renewable energy production is growing rapidly in the United Kingdom (UK). The wind power industry takes advantage of the country having some of the highest mean wind speeds in Europe. Future climate change, however, has the potential to alter the characteristics of the UK wind climate. Small changes in mean wind speed could produce much greater changes in wind energy output as the power generated is related to the cube of wind speed. This paper aims to use a simple method to provide insight into projected future UK wind climate and how this might differ from current patterns. A discussion of the scale of the projected impacts on the wind energy industry follows.     

Institutions in conflict? the climate change flexibility mechanisms and the multinational trading system

In an attempt to combat climate change on a global scale, the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) was adopted in conjunction with a wide range of policies both at national and international level. In particular, flexibility mechanisms-emissions trading system, joint implementation (JI) and clean development mechanism (CDM)-were incorporated in the Protocol to fulfil the commitment of the Parties by utilising a market system. Under the flexibility mechanisms, an artificial market is created in which the emission allowances or emission reduction units are traded. Not surprisingly, such measures might result in significant impacts on the trade of both goods and services, presumably creating the most complex and dynamic interaction with the Multilateral Trading System (MTS) which is overseen by the World Trade Organisation (WTO). If the implementation of flexibility mechanisms is identified as inconsistent with the requirements of the MTS, enforcement of such policies may prove difficult due to constraints imposed by GATT/WTO provisions.The purpose of this article is to scrutinise potential incompatibility between the implementation of flexibility mechanisms and GATT/WTO provisions. The rules governing the implementation of flexibility mechanisms have yet to be decided due to the divergent views of States regarding the design of the mechanisms. Thus, the analysis of the interaction will be undertaken based on hypothetical scenarios of each mechanism to account for all possible consequences of their implementation. Such an analysis will facilitate detection of any potential conflicts between the implementation of flexibility mechanisms and the trade regimes in advance, thus encompassing the potential incompatibility in designing the mechanisms and helping achieve increasingly effective implementation of flexibility mechanisms.     

Has climate change driven spatio-temporal changes of cropland in northern China since the 1970s?

Improving the understanding of cropland change and its driving factors is a current focus for policy decision-makers in China. The datasets of cropland and cropland changes from the 1970s to the 2000s were used to explore whether climate change has produced spatio-temporal changes to cropland in northern China since the 1970s. Two representative indicators of heat and water resources, which are important determinants of crop growth and productivity, were considered to track climate change, including active accumulated temperatures ≥10 °C (AAT10) and the standardized precipitation evapotranspiration index (SPEI). Our results showed that rapid cropland change has occurred in northern China since the 1970s, and the area of cropland reclamation (10.23 million ha) was much greater than that of abandoned cropland (2.94 million ha). In the 2000s, the area of cropland with AAT10 higher than 3,000 °C·d increased, while the area of cropland with an SPEI greater than 0.25 decreased compared to the 1970s, 1980s and 1990s. It appears that climate warming has provided thermal conditions that have aided rapid cropland reclamation in northern China since the 1970s, and drier climatic conditions did not become a limiting factor for cropland reclamation, especially from the 1990s to the 2000s. Approximately 70 % of cropland reclamation areas were located in warmer but drier regions from the 1990s to the 2000s, and approximately 40 % of cropland abandonment occurred in warmer and wetter conditions that were suitable for agriculture during the periods from the 1970s to the 1980s and the 1990s to the 2000s. Our results suggest that climate change can be considered a driving factor of cropland change in the past several decades in northern China, in addition to socioeconomic factors.     

Amplification or suppression: Social networks and the climate change—migration association in rural Mexico

Increasing rates of climate migration may be of economic and national concern to sending and destination countries. It has been argued that social networks—the ties connecting an origin and destination—may operate as “migration corridors” with the potential to strongly facilitate climate change-related migration. This study investigates whether social networks at the household and community levels amplify or suppress the impact of climate change on international migration from rural Mexico. A novel set of 15 climate change indices was generated based on daily temperature and precipitation data for 214 weather stations across Mexico. Employing geostatistical interpolation techniques, the climate change values were linked to 68 rural municipalities for which sociodemographic data and detailed migration histories were available from the Mexican Migration Project. Multi-level discrete-time event-history models were used to investigate the effect of climate change on international migration between 1986 and 1999. At the household level, the effect of social networks was approximated by comparing the first to the last move, assuming that through the first move a household establishes internal social capital. At the community level, the impact of social capital was explored through interactions with a measure of the proportion of adults with migration experience. The results show that rather than amplifying, social capital may suppress the sensitivity of migration to climate triggers, suggesting that social networks could facilitate climate change adaptation in place.     

Is adjustment of breeding phenology keeping pace with the need for change? Linking observed response in woodland birds to changes in temperature and selection pressure

Despite the recent plethora of studies investigating biotic implications of climate change, most research has been undertaken without the need for change being quantified. Failure to link observed responses to selection pressure is a fundamental omission because whether change is appropriate cannot then be determined. We use almost 7,000 records to analyse long-term (1974–2004) changes in breeding phenology for six co-occurring woodland birds at a site with significantly increasing spring temperatures. We link observed change to changes in selection for early laying (calculated using differential breeding success as the season progresses) to determine whether change is: (1) necessary, (2) appropriate, and (3) sufficient. Three (resident) species—blue tit, great tit, and nuthatch—started clutches significantly earlier over time without selection for early laying becoming stronger over the same period. This suggests that observed advancements are appropriate, and sufficient, to track climate change. For another species—coal tit—there was no change in lay date, and although there was always selection to lay early, selection intensity did not change over time. For this, the earliest-laying species, bet-hedging to prevent maladaptation (laying too early) or stabilising selection may be acting to maintain phenological inertia, even when phenological change could be adaptive. For the final two (migratory) species—pied flycatcher and redstart—there was no temporal change in lay date, despite selection for early laying becoming significantly stronger over time. This study indicates that some species are tracking climate change successfully while ecologically-similar species, at the same study site, are failing to do so.     

Food security or economic profitability? Projecting the effects of climate and socioeconomic changes on global skipjack tuna fisheries under three management strategies

We investigate the interactions between anthropogenic climate change, socioeconomic developments and tuna fishery management strategies. For this purpose, we use the APECOSM-E model to map the effects of climate change and commercial fishing on the distribution of skipjack tuna biomass in the three oceans, combined with a new bioeconomic module representing the rent or profit of skipjack fisheries. For forcing, we use Representative Concentration Pathway (RCP) 8.5, the highest emission scenario for greenhouse gas concentrations presented in the IPCC’s Fifth Assessment Report (AR5), and the IPCC Socioeconomic Shared Pathway (SSP) 3, which is characterized by low economic development and a strong increase in the world population. We first investigate the impact of climate change on regional skipjack abundance, catches and profits in three oceans (Atlantic, Indian and Pacific) in 2010, 2050 and 2095. We then study the effects of three management strategies (maximum sustainable yield or MSY, maximum economic yield or MEY, and zero rent or ZR) on the future distribution of fishing fleets between oceans and on global economic rent.Our model projections for 2050 and 2095 show an increase in global skipjack biomass compared to 2010 and major changes in its distribution, impacting local and regional fishing efforts. The Pacific Ocean will continue to dominate the skipjack market.In our modeling of management strategies, the currently predominant MSY strategy would have been unprofitable in 2010, due to a decreased catch per unit effort (CPUE). In the future, however, technological developments should increase fishing efficiency and make MSY profitable.In all the scenarios, a MEY strategy is more profitable than MSY but leads to the lowest catches and the highest prices. This raises ethical questions in a world where food security may become a top priority.In the scenarios where MSY generates an economic loss (e.g. 2010), a ZR strategy allows global stocks to be exploited at high but still profitable levels. Conversely, in the scenarios where MSY is profitable, (e.g. 2095) ZR leads to overfishing and smaller global catches.We conclude that the most appropriate management strategy at any time is likely to change as environmental and socioeconomic conditions evolve. The decision to follow one or other strategy is a complex one that must be regularly reviewed and updated.     

Future makers or future takers? A scenario analysis of climate change and the Great Barrier Reef

The extent to which nations and regions can actively shape the future or must passively respond to global forces is a topic of relevance to current discourses on climate change. In Australia, climate change has been identified as the greatest threat to the ecological resilience of the Great Barrier Reef, but is exacerbated by regional and local pressures. We undertook a scenario analysis to explore how two key uncertainties may influence these threats and their impact on the Great Barrier Reef and adjacent catchments in 2100: whether (1) global development and (2) Australian development is defined and pursued primarily in terms of economic growth or broader concepts of human well-being and environmental sustainability, and in turn, how climate change is managed and mitigated. We compared the implications of four scenarios for marine and terrestrial ecosystem services and human well-being. The results suggest that while regional actions can partially offset global inaction on climate change until about mid-century, there are probable threshold levels for marine ecosystems, beyond which the Great Barrier Reef will become a fundamentally different system by 2100 if climate change is not curtailed. Management that can respond to pressures at both global and regional scales will be needed to maintain the full range of ecosystem services. Modest improvements in human well-being appear possible even while ecosystem services decline, but only where regional management is strong. The future of the region depends largely on whether national and regional decision-makers choose to be active future ‘makers’ or passive future ‘takers’ in responding to global drivers of change. We conclude by discussing potential avenues for using these scenarios further with the Great Barrier Reef region's stakeholders.     

Who determines transformational change in development and climate finance?

The language of transformational change is increasingly applied to climate policy, and particularly in climate finance. Transformational change in this context is used with respect to low-carbon development futures, with the emphasis on mitigation and GHG metrics. But, for many developing countries, climate policy is embedded in a larger context of sustainable development objectives, defined through a national process. Viewed thus, there is a potential tension between mitigation-focused transformation and nationally driven sustainable development. We explore this tension in the context of operationalizing the Green Climate Fund (GCF), which has to deal with the fundamental tension between country ownership and transformational change. In relation to climate finance, acceptance of diverse interpretations of transformation are essential conditions for avoiding risk of transformational change becoming a conditionality on development. We further draw lessons from climate governance and the development aid literature. The article examines how in the case of both the Clean Development Mechanism and Nationally Appropriate Mitigation Actions, there has been limited success in achieving both development objectives and ‘nationally appropriate’ mitigation. The development aid literature points to process-based approaches as a possible alternative, but there are limitations to this approach.

Policy relevance

The concept of transformational change has gained prominence in climate finance. The conundrum facing the GCF is that it seeks to support transformational change in the climate realm, in a context where countries may have competing priorities. Balancing or even transcending this tension is a fundamental design challenge for the GCF. A primary focus on mitigation, particularly if metrics of performance are tied exclusively to GHG reduction, raise concerns about diluting ownership by recipient countries and evokes concerns of conditionality or worse. The literature on development assistance has explored options notably conditions on process and adequate capacity, and suggests that there are no short cuts to building domestic ownership. Actors on climate change need to avoid the risk that transformational change is perceived as, and becomes, an imposed condition. The risk that transformation change, operationalized in the context of unequal power relations, becomes an imposition on development, needs to be avoided.     

Farmer adaptation,change and ‘crisis’ in the Sahel

Perceptions of a continuing crisis in managing Sahelian resources are rooted in five dimensions of the Sahel Drought of 1972–1974 as it was understood at the time: crises in rainfall (drought), food supply, livestock management, environmental degradation, and household coping capabilities. A closer examination of household livelihood and farming systems shows that adaptive strategies have been evolved in response to each of these imperatives. Illustrations are provided from recent research in north–east Nigeria. A systematic understanding of indigenous adaptive capabilities can provide a basis for policies enabling a reduction of dependency on aid assistance in the Sahel.     

Study on the Trace Species in the Stratosphere and Their Impact on Climate

The trace gases （O3, HCl, CH4, H2O, NO, NO2） in the stratosphere play an important role, not only in the photochemical processes in which the ozone layer destroyed, but also in the radiative processes. In this paper, we review the works on the distribution and variation of the trace gases in the stratosphere and their impact on climate, which have been carried out at the University of Science and Technology of China in the recent 20 years. The Halogen Occultation Experiment （HALOE） data were used to analyse the distribution and variation of the mixing ratio of these trace gases and the temperature trends in the stratosphere in the most recent decade. And the reanalyzed National Centers of Environmental Prediction （NCEP）/NCAR data were also used to give the temperature trends and compared with the results from HALOE data. Numerical simulations were also carried out to study the impact of ozone depletion on the global climate. In this review, the distributions of the trace gases, especially those over the Qinghai-Xizang Plateau, are discussed, and the variations and trends for the trace gases in various levels in the stratosphere have been given for the most recent decade. The temperature variation and the cooling trend obtained from HALOE data in the middle and lower stratosphere for the last 13 years are significant, which agree well with the results from NCEP/NCAR data. While the temperature trend in the upper stratosphere in this period do not seem to have much cooling. The numerical simulations show that either the Antarctic ozone hole or the ozone valley over Qinghai-Xizang Plateau affect not only the temperature and circulation in the stratosphere, but also the temperature, pressure and wind fields in the troposphere, then lead to the global climate change.     

Is climate change affecting wolf populations in the high arctic?

Gobal climate change may affect wolves in Canadas High Arctic (80° N) acting through three trophic levels (vegetation, herbivores, and wolves). A wolf pack dependent on muskoxen and arctic hares in the Eureka area of Ellesmere Island denned and produced pups most years from at least 1986 through 1997. However, when summer snow covered vegetation in 1997 and 2000 for the first time since records were kept, halving the herbivore nutrition-replenishment period, muskox and hare numbers dropped drastically, and the area stopped supporting denning wolves through 2003. The unusual weather triggering these events was consistent with global-climate-change phenomena.     

Unstoppable climate change? The influence of fatalistic beliefs about climate change on behavioural change and willingness to pay cross-nationally

Although climate change is an urgent problem, behavioural and policy responses have not yet been sufficient to either reduce the volume of greenhouse gas emissions or adapt to a disrupted climate system. Significant efforts have been made to raise public awareness of the dangers posed by climate change. One reason why these efforts might not be sufficient is rooted in people’s need to feel efficacy to solve complex problems; the belief that climate change is unstoppable might thwart action even among the concerned. This paper tests for the effect of fatalistic beliefs on behavioural change and willingness to pay to address climate change using two cross-national surveys representing over 50,000 people in 48 nations.

Key policy insights

• The perception that climate change poses a risk or danger increases the likelihood of behavioural change and willingness to pay to address climate change.

• The belief that climate change is unstoppable reduces the behavioural and policy response to climate change and moderates risk perception.

• Communicators and policy leaders should carefully frame climate change as a difficult, yet solvable, problem to circumvent fatalistic beliefs.

     

Climate change and migration: Is agriculture the main channel?

Migration and climate change are two of the most important challenges the world currently faces. They are connected as climate change may stimulate or hinder migration. One of the sectors strongly affected by climate change is agriculture, which is the source of income for most of the world's poor. Climate change may affect agricultural productivity and hence migration because of its impact on average temperatures and rainfall and because it increases the frequency and intensity of weather shocks. In this paper we use data on 108 countries from 1960 to 2010 to analyze the relationship between weather variations, changes in agricultural productivity and international migration. We find that negative shocks to agricultural productivity caused by climate fluctuations significantly increase emigration from developing countries, an especially strong impact in poor countries but less so in middle income countries. These results are robust to the definitions of the poor country sample, and to several checks and alternative explanations suggested by the literature. Importantly, our results point to a causal interpretation of the agricultural channel to explain the climate change-migration nexus.