Chapter 10 of the book by Sachs (2015) focuses on food insecurity, looking at the subject on a different level. First, Sachs (2015) focuses on explaining why food insecurity is a crucial matter by providing data on malnutrition around the globe. I was astounded to know that the proportion of hungry people in the world is close to 40%. At first, I did not believe the number, as it appeared obnoxious. However, as I continued reading the chapter, I realized that Sachs (2015) included obese people and people suffering from “hidden hunger” in this 40%. Moreover, the number is expected to grow in the nearest future, as the environmental shocks negatively affect crop yields while the population is continuously growing. While I was already aware of the food insecurity problem to some extent, the book helped me expand my understanding of world hunger. I realized that food insecurity goes beyond the people unable to provide food for their table. People unable to have healthy food for a wide variety of reasons is also a part of the problem. After discussing the problem of food insecurity in general terms, Sachs (2015) touches upon farm systems and ecology. Approximately 40% of the world’s land area is used for human food needs. It was remarkable for me that only 14 million square kilometers are occupied by farms, while the other 34 million are used for meadows and pasturelands. The problem is that in order to increase the number of lands used for farming, humans will need to use forest areas, as they are the most appropriate for farming in terms of climate and soil. Therefore, humans will need to destroy forests to use them for farming, which is already happening in the Amazon Basin, the Congo Basin, and the Indonesian archipelago. While reading this part of the chapter, I realized that the majority of the land is used to produce meat products. While it was not mentioned directly in the chapter, it is clear that around 71% of the land used for food needs are pastures and meadows, which implies that these lands are used to feed livestock. Moreover, I am sure that part of the 29% of arable lands is used to grow crops for livestock. Further in the chapter, Sachs (2015) mentions that up to 15 kilograms of crops are needed to produce 1 kilogram of beef. This implies that if humanity decreased its consumption of meat, it could have improved land-use efficiency. In other words, the increased consumption of meat is one of the central problems that affect food insecurity, and I was surprised that Sachs (2015) hardy touches upon this problem. After discussing the peculiarities of farming, Sachs (2015) turns to how environmental problems affect food security. The rise in temperatures will make it impossible for many areas to continue to grow crops, as crops will have to withstand increased heat and decreased water supply. The water is the central problem, as rivers are currently overused, and the amount of rainfall certain areas receive is decreasing. Apart from these problems, Sachs (2015) mentions that ocean acidification, chemical pollutants, invasive species, retreating glaciers, and excessive pumping of groundwater also have a negative effect on the farmlands. However, some of these problems are caused by farming