"H. sapiens took around 250,000 years to reach a global population of 1 billion in 1820, and just over 200 years to go from 1 billion to 8 billion. This was largely made possible by our species’ access to cheap, easy, exosomatic energy, mainly fossil fuels. Fossil fuels enabled us to reduce negative feedback (e.g. food shortages) and thus delay and evade the consequences of surpassing natural limits. In that same 200 year period, fossil energy (FF) use increased 1300-fold, fueling a 100-fold increase in real gross world product, i.e. consumption, and the human enterprise is still expanding exponentially."