According to the United Nations, water stress is when annual water supplies drop below 1,700 m3 per person. Water scarcity is defined as annual water supplies below 1,000 m3 per person. Under a normal circumstance, let us assume people consume 2500 m3 of water per person per year. More than 2.8 billion people in 48 countries will face either water stress or scarcity conditions by 2025. Of these 48 countries, 40 are expected to be in West Asia or Africa. By 2050, far more people could be facing water shortages, depending both on population projections and scenarios for water supplies based on global warming and consumption patterns. As a result, [ A ] billion people will be water stressed, and [ B ] billion people will be suffering from water scarcity in 2050. What would be the total global water consumption per day in 2050? Instruction
• You can presume the total global population of 8 billion (8 x 109 or 8,000,000,000) in 2025. • Fill in A and B. • Get the final answer using the unit of m3 per day.
Extra information: 1) presume the pop of 2050 stays as the same level of 2025, or 2) project/predict the pop of 2050 by looking into the population in 2020 (7.6 billion) and 2025 (8 billion). What matters is how you tackle and how you process your calculations with what assumptions. Please elaborate/articulate what/how you do Q2, and make reasonable scientific justifications