**3. Global perspectives**

Globally, more than 70 billion animals are slaughtered every year for food. On the basis of data provided by UN FAO, the five major groups of animals slaughtered are cows, chicken, goats, sheep, and pigs [19]. It is expected that by 2050, intensive farming production will double with the major advancement taking place in less industrialized countries. This expansion has had serious consequences because only the livestock sector generates about 18% of greenhouse gas which is more than any kind of transport. Moreover, 70% of the Earth's surface is directly or indirectly involved in livestock production leading to land degradation, environmental pollution, and other health-associated issues [20]. These problems will not go away on their own if more and more extensive farming systems are being shifted toward intensive animal farms where animals are raised in confinement at high stocking density using advanced machinery and biotechnology. Intensive farming production systems were the norms of Europe and America, but now this practice is increasingly becoming common in Asia and Latin America. According to UN reports, the global shift of farming systems and environmental problems associated with these systems has not given much importance which is why they now have become a serious concern [21].

There are numerous problems associated with intensive animal farming system, a few of which is discussed below:

### **3.1 Increased emission**

As in intensive farming system, animals are raised indoors, therefore large amount of energy is required for heating, cooling, and ventilation as well as for feed production and transportation producing more emissions of carbon dioxide and anthropogenic nitrous oxide (which stays in the atmosphere for up to 15 years) and has more global warming potential leading to depletion of ozone layer. The livestock sector generates 64% ammonia emissions thereby contributing to acid rain and acidification of biodiversity [22].

Worldwide, farm animals are also a source of methane emission. Methane has 23 times more global warming potential than carbon dioxide. The operation of intensive farm animals leads to increased emission of methane because of animal diet which also causes diseases in animals and emits 50% more methane than animals feed on grasses in open lands. The only reason is that in intensive system animals are raised on a concentrated high-protein diet (made up of 50% corn and 80% soybean). This food is cheap and easy to produce and animals by eating such diets put on weight faster. This emission of greenhouse gases will continue to increase as the intensive farming system spread to more and more developing countries [22].

#### **3.2 Climate changes**

Developing countries suffer more from the impact of climate change because of abrupt increase in hunger and disease. This is because developing nations have limited coping capacities and they are dependent upon climate-sensitive food and water supply chains. Climatic changes are responsible for food scarcity in developing sectors. Excessive flooding, storms, loss in biodiversity, land degradation, and water and air pollution affect developing countries mostly because of health, poverty, and infrastructure constraints [23].
