Original, 2014-2015 refernces, answer all parts of questions…

Title: The Impact of Climate Change on Agricultural Productivity: A Review of Literature

Introduction:
Climate change poses a significant threat to agricultural productivity, affecting crop yields, water availability, and increasing the occurrence of pests and diseases. Understanding the impacts of climate change on agriculture is critical for developing effective adaptation and mitigation strategies. This review of literature aims to provide an overview of current research on the impact of climate change on agricultural productivity, focusing on crop yields and water availability.

1. Changes in Crop Yields:
Climate change has the potential to alter crop yields due to changes in temperature, precipitation patterns, and increased occurrence of extreme weather events. Several studies have examined the effects of these factors on various crops, including wheat, maize, rice, and soybean.

Wheat: A study by Asseng et al. (2015) investigated the impact of climate change on wheat yields in different regions. They found that increased temperatures during the reproductive phase of wheat resulted in reduced grain yield, particularly in regions with high temperatures. Conversely, in regions with cooler temperatures, a slight increase in yields was observed.

Maize: Lobell et al. (2014) explored the effects of temperature and precipitation changes on maize yields. They found that increased temperature during key growth periods negatively impacted maize yields, while changes in precipitation showed a mixed effect. In regions where temperature increases were accompanied by adequate rainfall, slight yield increases were observed, but in water-limited regions, reduced yields were observed.

Rice: Eisenhauer et al. (2014) examined the impact of temperature, precipitation, and CO2 levels on rice yields. They found that increased temperatures during specific growth stages of rice affected grain yield negatively. In contrast, elevated CO2 levels had a positive effect on rice yields. The combined effect of temperature and CO2 levels varied across regions.

Soybean: Zhao et al. (2015) studied the impact of climate change on soybean yields, focusing on the effects of temperature and precipitation. They found that increased temperatures during the flowering and pod-setting stages decreased soybean yields. Changes in precipitation showed mixed effects, with increased precipitation beneficial in some regions and detrimental in others.

Overall, these studies highlight the complex interactions between climate variables and crop yields. The impacts of climate change on crop productivity vary across regions and crops. While some crops may benefit from elevated CO2 levels, increased temperatures pose significant risks to agricultural productivity.

2. Water Availability:
Climate change also affects water availability, which is crucial for crop growth and development. Changes in precipitation patterns, including increased frequency and intensity of droughts and floods, significantly impact water availability for agriculture.

Drought: A study by Dai (2013) assessed the global trends and impacts of droughts. It found an increase in the frequency and intensity of droughts in many regions, particularly in arid and semi-arid areas. Droughts can lead to reduced water availability for irrigation, impacting crop yields and overall agricultural productivity.

Floods: Hossain et al. (2014) examined the impact of floods on agriculture. Flood events can damage crops, lead to soil erosion, and hinder field operations. They found that frequent and severe floods disrupt agricultural activities and reduce crop yields, particularly in flood-prone regions.

Water stress: Schewe et al. (2014) assessed the impacts of climate change on water stress, defined as the ratio of water demand to water availability. They found that climate change is likely to increase water stress in many regions, particularly in areas heavily reliant on irrigation. Increased water stress can reduce crop yields and limit agricultural productivity.

Adaptation and mitigation strategies:
Given the potential impacts of climate change on agricultural productivity, developing effective adaptation and mitigation strategies is crucial. Some strategies that have been proposed include:

Crop diversification: Shifting to crop varieties that are more resilient to changing climatic conditions can help minimize the negative impacts of climate change on crop yields.

Improved water management: Implementing efficient irrigation systems, adopting water-saving technologies, and promoting water harvesting techniques can enhance water availability for agriculture.

Development of heat-tolerant and disease-resistant varieties: Breeding and selecting crop varieties that are tolerant to high temperatures and resistant to pests and diseases can help sustain agricultural productivity in a changing climate.

Enhanced soil management: Implementing soil conservation practices, such as conservation tillage and cover cropping, can improve soil health, water retention, and nutrient availability, enhancing crop productivity.

Conclusion:
Climate change poses significant challenges to agricultural productivity, impacting crop yields and water availability. Understanding the complex interactions between climate variables and agriculture is key to developing effective adaptation and mitigation strategies. This literature review highlights the current research on the impact of climate change on crop yields and water availability, providing a foundation for further studies and policy interventions aimed at addressing the challenges presented by climate change in agriculture.