Answer:
Deforestation.
Explanation:
Cattle grazing in Amazon rainforest is indeed the major cause of deforestation. It has been seen in Brazil since at least the 1970s: from the year 1966 to 1975, which attributed 38% of deforestation to huge-scale cattle grazing.
In Amazon, cattle grasslands cover 80% of deforested areas. The run-off of farmland contaminates streams. Fires that used to control files are often transmitted to remaining forest. Ranching deforestation even contributes to change in climate, dumping 340 million of tons of carbon per year into environment.
