Climate change impacts on investment in crop sowing machinery*

A model of investment in crop sowing machinery is applied to wheat production under current and projected climatic conditions at several locations in south‐western Australia. The model includes yield responses to time of sowing at each location given current and projected climatic conditions. These yield relationships are based on wheat growth simulation modelling that in turn draws on data from a down‐scaled global circulation model. Wheat price distributions and cost of production data at each location, in combination with the time of sowing yield relationships are used to determine a farmer's optimal investment in crop sowing work rate under each climate regime. The key finding is that the impacts of climate change on profit distributions are often marked, yet mostly modest changes in investment in work rate form part of the profit‐maximising response to climate change. The investment response at high versus low rainfall locations mostly involves increases and decreases in work rates, respectively. However, changes to investment in work rate within a broadly similar rainfall region are not always uniform. The impacts of climate change on investments in work rate at a particular location are shown to require knowledge of several factors, especially how climate change alters the pattern of yield response to the time of sowing at that location.     

Climate change and the Australian agricultural and resource industries

There is a limited case for assisting trade-exposed emissions-intensive industries during a transitional period during which Australian resource industries but not all of their major competitors are subject to emissions constraints. There is no case for protecting Australian industry from all adjustment and loss of asset values during the transition. The valid case is analogous to anti-dumping assistance, being confined to the case where weaker emissions constraints elsewhere would force adjustments that would be reversed later. The case for assistance is limited by the effect of others' weaker emissions constraints on global resource prices.     

Impacts of climate change on lower Murray irrigation*

This article evaluates irrigated agriculture sector response and resultant economic impacts of climate change for a part of the Murray Darling Basin in Australia. A water balance model is used to predict reduced basin inflows for mild, moderate and severe climate change scenarios involving 1, 2 and 4°C warming, and predict 13, 38 and 63% reduced inflows. Impact on irrigated agricultural production and profitability are estimated with a mathematical programming model using a two‐stage approach that simultaneously estimates short and long‐run adjustments. The model accounts for a range of adaptive responses including: deficit irrigation, temporarily following of some areas, permanently reducing the irrigated area and changing the mix of crops. The results suggest that relatively low cost adaptation strategies are available for a moderate reduction in water availability and thus costs of such a reduction are likely to be relatively small. In more severe climate change scenarios greater costs are estimated. Adaptations predicted include a reduction in total area irrigated and investments in efficient irrigation. A shift away from perennial to annual crops is also predicted as the latter can be managed more profitably when water allocations in some years are very low.     

全球气候变化及其影响--探索厄尔尼诺之谜

来自热带太平洋赤道附近水域大面积升温或降温，引起气候变暖与变冷异常的厄尔尼诺和拉尼娜现象，产生各种暴风雨、风暴潮、洪水泛滥和持续干旱等自然灾害，严重威胁人类生存环境，造成巨大经济损失。本文对近20年来世界范围厄尔尼诺现象及其影响，它的形成机理、物理过程及其产生原因进行了探讨，并介绍一些主要国家对厄尔尼诺/拉尼娜的监测和预防研究取得的进展。     

全球气候变化对海岛旅游地的影响与启示

气候既是海岛旅游业发展的自然条件,又是主要的资源,全球气候的异常变化影响海岛旅游资源的数量与质量、客流的空间与季节移动,并导致传统海岛旅游目的地的萎缩。全球气候变化对我国海岛旅游业的影响日益显著,必须及时调整海岛旅游发展的对策：大力发展生态旅游、可持续旅游;探究旅游者对气候变化的适应;改善海岛旅游目的地服务设施;重新进行海岛旅游规划;重视旅游主体人群的教育,以适应全球气候变化带来的巨大影响。     

Classical decision rules and adaptation to climate change*

One approach to rationalising policies for addressing potentially catastrophic climate change when such policies may prove unnecessary is to suppose the policies provide a form of social insurance even in the presence of pure uncertainty. Then, provided the policies are effective, such insurance can be justified as a precautionary or minimax response. Even if the policies are potentially ineffective however, intervention can be justified as an attempt to minimise the regret experienced by future generations. This reasoning extends to justify ‘all weather’ policies provided such policies always reduce policy costs. If, however, policy decisions provide ‘all weather’ benefits in only certain states of the world, this rationale breaks down. Minimising regret can establish a case for ‘mixed’ policy responses provided adopting a policy mix precludes the chance that intervention will fail altogether. Precautionary policies and policies which minimise regret are computed for a simple, dynamic, adaptive climate change planning problem and sufficient conditions for policy maker pessimism provided.     

Adaptation May Reduce Climate Damage in Agriculture by Two Thirds

Although climate change may severely impact agriculture, farmers can mitigate it by adapting. Using US data, we estimate the amount of potential loss in agricultural profits, due to climate change, that can be reduced by agricultural adaptation. We consider two panel frameworks that differ only in their fixed effects specifications, where this difference allows us to estimate the climate change impact on agricultural profits with or without adaptation. Comparing these estimates, we find that adaptation has the potential to offset about two‐thirds of the end‐of‐century loss in agricultural profits potentially resulting from climate change. We also find that the warmest region in the US (i.e. in the south) has the most to gain from adaptation.     

Investigating distance effects on environmental values: a choice modelling approach*

Analysis of the relationship between distance and willingness to pay (WTP) is important for estimation and transfer of environmental benefits. Several contingent valuation (CV) studies have investigated this topic, but results are mixed. This paper describes a choice modelling (CM) application that estimates distance effects on parameters of three environmental attributes. Combinations of these attributes create different management policies for native vegetation. The CM study is based on a sampling procedure that provides a geographically balanced sample and statistical tests to choose the best specification of the distance–WTP relationship. Welfare analysis shows that disregarding distance causes under‐estimation of individual and aggregated benefits and losses, seriously misdirecting resource allocation.     

Agricultural policies and food systems: Priorities for indicator development

Existing indicators of agricultural protection and support were developed primarily to gauge the market and welfare effects of government policies. They have shed light on a wider range of impacts through their use in economic models and empirical analysis. The rising scale of support to agriculture globally, and continued reliance on market distorting policy instruments, make this work as important as ever. Deeper investments are nonetheless needed to address heightened concerns about the spill-over impacts of agricultural policies on the performance of food systems, in particular with respect to food security and nutrition, rural livelihoods, resource use and the environment, and global emissions. A first area for development is improved measures of policies to correct agriculture's externalities. A priority here is to develop a carbon tax equivalent of sectoral mitigation efforts. A second area is to provide a clearer delineation of government spending on private versus public goods. This would make a valuable contribution to a ‘repurposing’ agenda that seeks to identify how agricultural budgets can be spent more effectively, as well as the scope for transferring resources to wider social priorities, such as public health and climate action.     

The impacts of climate change on Australia and New Zealand: a Gross Cell Product analysis by land cover*

This paper examines the newly constructed geographically scaled economic output measure, Gross Cell Product (GCP), of Australia and New Zealand to quantify the impacts of climate change in the region. The paper discusses advantages of using the GCP instead of the Gross Domestic Product. The paper reveals that the GCP falls sharply as temperature increases in the region. A 1°C increase in temperature would decrease the productivity with an elasticity of ?2.4. A 1 per cent decrease in precipitation would decrease productivity with an elasticity of ?2.3. However, forest vegetation on the coasts will benefit from initial warming. We find that the changes in climate means are potentially more harmful than changes in climate variability. In the long term, a 3.4° warming coupled with 6.6 mm decrease in rainfall would decrease the GCP by 34 per cent by 2060. The damage is largely accounted for by population effects. The paper confirms that Australia is highly constrained by climate and geographic factors.     

An accelerating treadmill and an overlooked contradiction in industrial agriculture: Climate change and nitrogen fertilizer

In this article, we explore if and why farmers are responding to the impacts of climate change with practices that increase greenhouse gas emissions. Our examination focuses on heavy rainfall events and Midwestern corn farmers' nitrogen fertilizer management. Due to climate change, the frequency and intensity of heavy rain events is increasing across the Midwest. These events increase nitrogen loss to the environment and introduces economic risks to farmers. Drawing from a theoretical framework that merges O'Connor's second contradiction of capitalism and Schnaiberg's treadmill of production, we argue farmers' responses to these events reflect the second contradiction, increasing contributions to climate change, and are shaped by treadmill‐like political‐economic pressures. We examine this using a qualitative sample of 154 farmers across Indiana, Iowa, and Michigan. Given profit imperatives, adapting farmers in our sample primarily used increased nitrogen application rates to reduce their vulnerability to heavy rains. As nitrogen rate is directly associated with nitrous oxide emissions, this adaptive strategy is effective but increases agricultural contributions to climate change. This preliminarily suggests that the political‐economic structure encourages farmers to respond to climate change in ways that accelerate the environmental contradictions of industrial agriculture.     

Complexity in choice experiments: choice of the status quo alternative and implications for welfare measurement*

We examine the propensity of respondents to choose the status quo (SQ) or current situation alternative as a function of complexity in two separate state‐of‐the‐world choice experiments. Complexity in each choice set was characterized as the number of single and multiple changes in levels of attributes from the current situation and the order of the choice task in the sequence of multiple tasks provided to respondents. We show that increasing complexity leads to increased choice of the SQ and that a respondent’s age and level of education also influenced this choice. We outline the effects of the alternate approaches for incorporating the SQ into welfare measurement. These findings have implications for the design of stated preference experiments, examining passive use values and for empirical analysis leading to welfare measurement.     

气候变化和林业:REDD入门

在如何应对气候变化的讨论中,最有争议的问题之一是REDD(减少毁坏和林地退化造成的碳排放)。在基于市场减排战略中的作用,分析审查REDD活动的成本表明,REDD不但在减少GHG排放的全球战略中发挥重要作用,还可以保护热带雨林提供生物多样性和重要生态系统服务。但是REDD项目限于在一定地域,除非全球森林都被纳入REDD,否则漏洞无法消除,此外,REDD在政策设计问题上存在一定争议,因此还需进一步的研究讨论。     

Climate change adaptation in agriculture: A computable general equilibrium analysis of land-use change in Nepal

This paper investigates the feasibility of changes in cropland-use as an adaptation strategy to minimise the economy-wide costs of climate change on agriculture. Nepal makes an interesting case study as it is one of the most vulnerable agricultural economies within South Asia. We develop a comparative static multi-household computable general equilibrium (CGE) model for Nepal, with a nested set of constant elasticity of transformation (CET) functional forms, to model the allocation of land within different agricultural sectors. Land transformation elasticities in these CET functions are allowed to reflect the ease of switching from one crop to another based on their agronomic characteristics. The results suggest that, in the long run, farmers in Nepal tend to allocate land to crops that are comparatively less impacted by climate change, such as paddy, thereby minimising the economy-wide impacts of climate change. Furthermore, the results reveal that land-use change tends to reduce the income disparity between different household groups by significantly moderating the income losses of marginal farmers. Therefore, it is suggested that policy makers in Nepal should prioritise schemes such as providing climate-smart paddy varieties (i.e., those that are resistant to heat, drought and floods) to farmers, subsidising fertilizers, improving agronomic practices, and educating farmers to switch from crops that are highly impacted by climate change to those that are not, such as paddy.     

Modelling outcome‐related risk in choice experiments

In this study, we introduce information on outcome‐related risk as an additional attribute in a choice model of preferences for a land‐based climate change mitigation project. We provide a comprehensive comparison of different model specifications arising from different behavioural assumptions about the way that respondents process information on outcome‐related risk within the choice task. We find significant differences between several specifications in terms of both model fit and WTP estimates. The behavioural assumptions made when choosing a particular model specification, and reasons that motivate them should be made explicit, and consequences of using different specifications should not be ignored.     

应对气候变化:北京市防沙治沙战略思考

介绍了影响北京市的沙尘源、沙化土地历史分布和现状,分析了新中国成立60年来北京市沙化土地的动态变化趋势和防沙治沙重点工程的成效,提出了应对气候变化背景下的北京市防沙治沙新战略:指导思想是依托生态,聚集资源,打造产业,应对气候变化;重点是建立高标准的生态防护体系、高效益的产业开发体系、高水平的监测评价体系和高效率的服务保障体系。     

Climate change reduces the mitigation obtainable from sequestration in an Australian farming system

Agricultural research on climate change generally follows two themes: (i) impact and adaptation or (ii) mitigation and emissions. Despite both being simultaneously relevant to future agricultural systems, the two are usually studied separately. By contrast, this study jointly compares the potential impacts of climate change and the effects of mitigation policy on farming systems in the central region of Western Australia’s grainbelt, using the results of several biophysical models integrated into a whole‐farm bioeconomic model. In particular, we focus on the potential for interactions between climate impacts and mitigation activities. Results suggest that, in the study area, farm profitability is much more sensitive to changes in climate than to a mitigation policy involving a carbon price on agricultural emissions. Climate change reduces the profitability of agricultural production and, as a result, reduces the opportunity cost of reforesting land for carbon sequestration. Nonetheless, the financial attractiveness of reforestation does not necessarily improve because climate change also reduces tree growth and, therefore, the income from sequestration. Consequently, at least for the study area, climate change has the potential to reduce the amount of abatement obtainable from sequestration – a result potentially relevant to the debate about the desirability of sequestration as a mitigation option.     

Leadership in agricultural machinery circles: experimental evidence from Tajikistan

Leadership is critical for the viability of rural groups. The way in which leadership is legitimised can mediate leader and group member behaviour in the face of social dilemmas. Yet there has been scant research on leader‐follower dynamics in naturally occurring groups. Highlighting the case of agricultural machinery circles in Tajikistan, the effect of leading by example on investments to a collective good is studied in a framed field experiment. To increase realism, and contrary to standard economic experiments, this investment is a voucher allowing the group to make a real‐world machinery purchase at reduced costs. Two treatments manipulate leaders’ legitimisation. Elected leaders achieve 30 per cent higher contributions to the collective investment against a baseline version without a leader. Contributions remain, on average, relatively stable over the course of the game. The results are discussed with reference to the debate on external intervention in agricultural producer organisations.     

Climate adaptation imperatives: untapped global maize yield opportunities

Climate change represents an unavoidable and growing challenge to food security, imposing new adaptation imperatives on all farmers. Maize is arguably the world's most productive grain crop, as measured by grain yield. However, maize yields vary dramatically due to many factors, including soils, climate, pests, disease, agronomic practices, and seed quality. The difference between observed yields and those achievable by optimized crop production methods is called the yield gap. In this work we quantified the current yield gap for 44 countries through the use of a large private-sector data set recently made available to the crop modelling community. The yield gap was quantified for three groups of countries, categorized by level of intensification. Observed yield gaps for high, medium, and low levels of intensification are 23%, 46%, and 68%, respectively. If all maize production countries were able to shrink their yield gap to 16.5% (as in the USA) an additional 335?million metric tons (MMT) of maize grain would be produced. This represents a 45% increase over the 741?MMT produced by these countries in 2010. These data demonstrate that a major untapped maize yield opportunity exists, especially in those countries where intensification has not kept pace with the rest of the world.