Collecting firewood was the biggest reason for cutting down forests in the past.
Curtis and colleagues (2018) analysed Google Earth to distinguish between five causes of deforestation:
Commodity-driven means that the forests are permanently turned into something else, this could be agriculture, mining, or oil and gas production.
Other sources (1, 2, 3) show us that most of those commodities are meat. So together with 'shifting agriculture', food is the biggest cause of deforestation.
The red arrow represents our human influence on the carbon cycle. It's small compared to nature, but big enough to bring the system out of balance.
About a quarter of the arrow comes from cutting down trees and other ways of affecting the carbon cycle of plants and animals.
24% of human greenhouse gas emissions come from 'Agriculture, Forestry and Other Land Use' (IPCC, 2018).
Our total greenhouse gas emissions not only include CO2, but also methane and nitrous oxide.
Almost all of the CO2 emissions from' Agriculture, Forestry and Other Land Use' come from deforestation. 'Enteric fermentation' is a topic for later; these are the methane burps from cows.