We already know several impacts of global warming on the environment. These include the melting of polar ice caps (increasing sea level), an increase in the amount of precipitation on a global level and the effects these events have on animal populations. A recent study found that if carbon emissions and greenhouse gases are not substantially reduced, then a serious decline in crop productivity will be seen. From the article, there seems to be a significant difference in expected effects to developing countries versus rich countries. Rich countries tend to have lower average temperatures where developing countries tend to have higher average temperatures. As these temperatures increase, they rise above crop tolerances making it very difficult to grow a sufficient amount of food. For example, India already has an average temperature of 27 degrees Celsius (80 degrees Fahrenheit), and with that temperature expected to rise in the next 50 years it is not ideal for growing crops. Experts predict a 30-40% decrease in productivity in India alone. Overall agricultural productivity for the entire world is projected to decline 3-16% in the next 50 years if the levels of greenhouse gases continues to rise as it is now.
So along with global warming comes increased temperatures which will potentially cause a decrease in crop output. To combat this we need better agriculture technology and techniques to offset the climate change. Many things need to be considered when trying to use technology to solve this problem. First, the demand for food is going to continue to increase as the global population increases. Second, crops are used for other things besides food sources. We've already seen the effects of using grain for bio-fuels instead of food. So with additional investment into crop production the effects of climate change can be managed, however, the additional technology used will cost more money which will increase the cost it takes to grow the food. So either way we're going to see an increase in crop prices.
For more information of the causes and effects of climate change: