Concept, Causes and Impacts of Climate Change

The number of farmers will continue to increase without appropriate adaptation to mitigate the potential impacts of climate change. Therefore, to reduce vulnerability to climate change requires that farmers implement effective adaptation measures (Adger et al., 2006). Changing production methods to cope with climate change is necessary to maintain and improve productivity to meet the increasing food demand of the people (Otitoju and Enete, 2014) and is the key to coping well with the damages caused by climate change in the future. Some farmers may adjust and adapt better than others depending on many factors such as agricultural management practices, land management, production characteristics and socio-demographics (Mabe et al., 2014). Identifying appropriate adaptation measures for each crop/livestock type and analyzing factors influencing the decision to adopt adaptation measures is necessary to enhance understanding of farmers' adaptation behavior. In addition, climate change has the potential to reduce the production efficiency of the agricultural sector, the consequences of which directly affect sustainable farming systems, reducing crop and livestock productivity (Aulong and Kast, 2011). Some authors have demonstrated that the production efficiency of some crops and livestock is low due to the impact of climate change (Makki et al., 2010; Nagothu et al., 2012; Cao Le Quyen et al., 2015; Tasnim et al., 2015; Tran Dai Nghia, 2015). This is because agricultural production is closely linked to the natural and social environment, so the extent to which climate change can affect agricultural systems depends largely on these factors.

Thus, previous studies have been conducted but they are only specific studies in each specific area, in different fields without seeing the overall picture of the vulnerable context, the level of vulnerability and corresponding adaptation measures, as well as the impact of these measures on the production efficiency of farming households. Therefore, a study addressing these relationships of farming households for a specific crop/livestock is necessary. The research results will contribute to the theoretical and empirical basis for the ongoing and extremely complex issue of climate change, contributing to the stabilization and development of agricultural production.

1.2. Practical urgency

Maybe you are interested!

Vietnam is one of the five most vulnerable countries in the world due to climate change, including the Mekong Delta (Dasgupta et al. , 2007; Nguyen Mau Dung, 2010) and especially the coastal provinces (World Bank, 2010). Aquaculture is confirmed to contribute the least to promoting climate change of the earth but is the sector most affected by climate change (Nguyen Ngoc Thanh et al., 2015). Aquaculture is one of the important livelihoods of coastal residents in Vietnam, but ranks 27th out of 132 countries in the world in terms of TDBTT due to the impact of climate change (Alison et al., 2009). Meanwhile, the marine shrimp farming industry in Vietnam occupies an important position in the economic development strategy, contributing to creating jobs, increasing income and reducing poverty for millions of coastal people (Institute of Economics and Fisheries Planning, 2015) and is one of the top 5 countries in the world in terms of farmed shrimp production (FAO, 2015). Vietnam's shrimp products are present in 99 countries around the world (such as Japan, China, Korea, the US, the EU and Australia). Whiteleg shrimp occupies a dominant position in the structure of Vietnam's shrimp export products (accounting for 68.7%), black tiger shrimp accounts for 23% and other shrimp accounts for 8.3%. The area of marine shrimp farming nationwide in 2018 reached 712.7 thousand hectares, an increase of 1.4% over the previous year. Black tiger shrimp output in 2018 is estimated at 274.3 thousand tons, an increase of 5.5% over the previous year; Whiteleg shrimp production reached 492.3 thousand tons, up 10% (Directorate of Fisheries, 2018). However, in recent years, climate change is affecting the structure and function of coastal ecosystems, becoming a threat to the growth of the shrimp farming industry. Climate change can directly or indirectly affect farmed shrimp through water sources, area, farming environment, breeds and diseases, affecting productivity and output. Small-scale coastal shrimp farming communities are among the most sensitive to climate change in terms of economy, society and adaptive capacity (Institute of Fisheries Economics and Planning, 2015). Research by Kam et al. (2010) in the Mekong Delta showed that without adaptation solutions, shrimp farming households' income could decrease by 130 million VND/ha in 2020 and 950 million VND/ha in 2050.

Ben Tre is one of the coastal provinces in the Mekong Delta region with a 65 km long coastline, creating favorable conditions for aquaculture development. In particular, shrimp farming is one of the key industries of the province, concentrated in the three coastal districts of Binh Dai, Ba Tri and Thanh Phu (Nguyen Trong Hoai and Nguyen Van Hieu, 2013). The marine shrimp farming industry has made many important contributions to the socio-economic development of the locality with an area of about 35 thousand hectares in 2018, an output of about 55,000 tons, ranking fifth in terms of area and output nationwide. However, Ben Tre is also one of the localities most severely affected by climate change and rising sea levels (MORE, 2016), in which coastal districts suffer the most damage (Nguyen Thi Kim Anh et al., 2013). The most vulnerable industry is aquaculture, followed by forestry and agriculture. Marine shrimp farming livelihoods are ranked at a medium-high risk level due to pressures from development activities and climate change (Le Anh Tuan et al., 2012) and the adaptive capacity of shrimp farmers is only at a medium-low level (Le Anh Tuan et al., 2012; Le Thi Kim Thoa, 2013). Shrimp farming households face many difficulties in accessing credit capital, seeds, feed, medicine, labor, land area and agricultural extension services. In particular, in recent years, climate change phenomena such as rising temperatures, droughts, rising sea levels, storms, unseasonal rains, landslides, and saline intrusion have had a strong impact and significantly reduced the efficiency of shrimp farming in the area. To cope with these impacts, local authorities have made many efforts to prevent and mitigate the impacts of climate change on production sectors, including marine shrimp farming. Many infrastructure projects have been implemented, and a number of propaganda activities to raise awareness of climate change for the shrimp farming community have also been carried out by authorities at all levels. However, the results achieved are not high, the loss of human life, property, and annual output caused by natural disasters to shrimp farming households is still serious (Ben Tre Provincial People's Committee, 2018). The above difficulties and obstacles are important reasons for the low efficiency of shrimp farming households. In order to minimize the adverse impacts caused by climate change, it is important to assess vulnerability, adaptation measures, and production efficiency.

output of shrimp farming households in the context of climate change. Therefore, the topic "Analysis of climate change adaptation measures and the effectiveness of shrimp farming households in Ben Tre province " was chosen to implement. The research results of the topic will be knowledge and understanding at the micro level about the general picture of the impact of climate change on the activities of shrimp farming households and will be an important basis for local authorities to design support policies for the development of the shrimp farming industry, contributing to helping shrimp farming households limit the obstacles caused by climate change.

2. Research objectives

2.1. General objectives

Analysis of climate change adaptation measures and efficiency of shrimp farming households in Ben Tre province

2.2. Specific objectives

Objective 1: Analyze the current status of climate change adaptation of shrimp farming households in Ben Tre province

Objective 2: Assess the vulnerability of marine shrimp farming households to climate change in Ben Tre province

Objective 3: Analyze factors affecting the decision to apply climate change adaptation measures of shrimp farming households in Ben Tre province.

Objective 4: Analyze the impact of climate change adaptation measures on the efficiency of marine shrimp farming in Ben Tre province.

Objective 5: Propose solutions to improve climate change adaptation and production efficiency for shrimp farming households in Ben Tre province.

3. Research questions

To achieve the specific research objectives mentioned above, the topic focuses on answering the following questions: (1) What is the situation of adaptation to climate change of shrimp farming households in Ben Tre province?; (2) Is the level of vulnerability of shrimp farming households to climate change in Ben Tre province very high, high, medium, low or very low?; (3) What factors affect the decision to apply climate change adaptation measures of shrimp farming households in Ben Tre province?; (4) The level of technical and economic efficiency of shrimp farming households in Ben Tre province?

What is the climate change context achieved? (5) How effective are the climate change adaptation measures that shrimp farming households in Ben Tre province are applying? (6) To improve the climate change adaptation capacity and production efficiency of shrimp farming households in Ben Tre province, what solutions and policies need to be implemented?

4. Research subjects

The research object of the topic is theoretical and practical issues on vulnerability, adaptation and production efficiency of shrimp farming households. The survey objects are households raising improved extensive black tiger shrimp and intensive whiteleg shrimp in Ben Tre province, these are two popular shrimp farming models in the Mekong Delta in general and Ben Tre province in particular. The study does not survey shrimp farming facilities at farm or company scale, production and trading establishments of input materials, purchasing, preliminary processing, processing establishments and consumption markets.

5. Scope of research

5.1. Spatial scope

The topic focuses on studying the vulnerability, adaptation measures to climate change and production efficiency of shrimp farming households in Ben Tre province in general and in-depth research in three coastal districts: Ba Tri, Binh Dai and Thanh Phu.

5.2. Time range

Secondary data: The weather change situation was considered during the period from 1980 to 2017, the socio-economic situation and shrimp production during the period from 2012 to 2017 in Ben Tre province.

Primary data: Surveyed from shrimp farming households in Ben Tre province

2018.

6. Scientific and practical significance

6.1. Scientific significance

Applying the IPCC approach, the study proposed a set of indicators to assess the vulnerability of shrimp farming households to climate change, including 3 main indicators, 13 sub-indicators and 42 variables. The set of indicators was applied to assess the vulnerability of marine shrimp farming households to climate change in Ben Tre province. With the results achieved and from practical application in the study, it is possible to summarize this set of indicators

along with calculation methods to replicate and apply to other aquaculture areas or models with similar conditions.

The study identified 14 climate change adaptation measures of shrimp farming households divided into 4 groups: adjusting crop calendar, adjusting techniques, diversifying production and preventing risks. Applying the Multivariate Probit model, the study measured the interaction and influence of factors including household characteristics, access to social services and awareness of climate change on the decision to apply climate change adaptation measures.

The study has applied the issue of climate change impact into the assessment of technical efficiency and economic efficiency of marine shrimp farming households. Based on the Cobb-Douglas model of marginal production function and stochastic marginal profit and using the one-step estimation method, the study has measured the impact of vulnerability due to climate change and climate change adaptation measures on technical efficiency and economic efficiency of marine shrimp farming households.

6.2. Practical significance

The thesis was conducted on shrimp farming households in Ben Tre province, a locality identified to be heavily affected by climate change, especially coastal districts - where the area of marine shrimp farming is concentrated. The research results help shrimp farming households to recognize the current status of climate change adaptation and shrimp farming efficiency in order to adjust production accordingly. The research results also provide additional practical basis for climate change risk management for the Ben Tre shrimp farming industry.

The thesis has proposed a number of solutions to improve climate change adaptation and efficiency of marine shrimp farming. This will be an important reference document for the leaders of Ben Tre province and the agricultural sector of Ben Tre province to integrate climate change adaptation issues into planning and development planning of the shrimp farming industry.

The research results supplement the database and draw useful scientific conclusions on the assessment of TDBTT, adaptation measures, production efficiency and the relationship between them. The research methods and application models can be applied to other localities or agricultural production areas. The thesis provides more information for studying and teaching at universities.

research institute, and at the same time is a scientific basis for researchers and scientists to develop further research directions.

7. Structure of the thesis

The thesis consists of an introduction, conclusion-recommendations and 3 chapters with the following contents:

Introduction. This chapter presents the urgency, objectives, objects and scope of the research, research questions, scientific and practical significance of the thesis.

Chapter 1: Theoretical and practical basis. This chapter presents the theoretical basis related to the research content of the thesis including climate change, vulnerability to climate change, adaptation to climate change and production efficiency. At the same time, it evaluates existing research works of domestic and foreign authors related to the research content, pointing out the issues that the thesis topic needs to focus on researching and solving as a basis for proposing a general analytical framework.

Chapter 2: Research methodology. This chapter presents the method of data collection of the thesis and applies analytical methods for each research objective with empirical models. This chapter is the foundation for analysis to produce research results in a scientific manner.

Chapter 3: Research results and discussion. This chapter presents all research results (tables and illustrations), discussions, comments and assessments based on scientific data collected during the research process and compared with research results of other authors through reference documents. The main content of this chapter includes assessing the current status of adaptation to climate change of shrimp farming households, assessing the TDBTT of shrimp farming households due to climate change, analyzing factors affecting the decision to apply climate change adaptation measures, evaluating the production efficiency of shrimp farming households under the impact of climate change and analyzing the impact of adaptation measures on that production efficiency. Finally, proposing solutions to adapt to climate change, improving production efficiency for shrimp farming households in Ben Tre province.

Conclusion and recommendations. This chapter summarizes the research results achieved in accordance with the set objectives. At the same time, based on the research, recommendations are made for shrimp farmers and organizations/units on how to implement the proposed solutions.

Chapter 1

THEORETICAL AND PRACTICAL BASIS

In Chapter 1, the main contents presented include: (i) concepts, causes and impacts of climate change; (ii) livelihood resources in the context of climate change; (iii) vulnerability to climate change and assessment methods applied in practice; (iv) theory and practice of adapting to climate change in agricultural production; (v) production efficiency and methods of measuring agricultural production efficiency in practice; (vi) overview of the research area.

1.1. Concept, causes and impacts of climate change

1.1.1. Concept and causes of climate change

There are many different concepts of climate change (IPCC, 2007; MORE, 2008), each concept stands on a separate perspective but all agree on the understanding of climate change over a long and identifiable period of time. Among them, the concept of the Intergovernmental Panel on Climate Change (IPCC) is widely accepted. Accordingly, climate change is a change in the state of the climate system, which can be identified by changes in the average and variability of its properties, maintained over a long period of time, typically decades or longer.

Climate change is caused by two main factors: natural and human. Natural causes of climate change include changes in the intensity of sunlight, the appearance of sunspots, volcanic activity, ocean changes and changes in the Earth's orbit. However, according to research results and publications from the IPCC, the main cause of climate change is human socio-economic development activities that have increased the concentration of greenhouse gases (N 2 O, CH 4 , H 2 S, CFCs and CO2) in the atmosphere, causing global warming, changing the climate system and affecting the global environment. In the IPCC report (2007), a series of studies showed that human activities contribute to 90% of the causes of climate change.

Comment