IN 1950, there were only 2.5 billion people in the world. The human population is projected to reach 8.5 billion in 2030, 9.7 billion in 2050, 10.4 billion in the mid-2080s, and perhaps 10.8 billion in 2100, despite a recent slight slowdown in population growth. (Source: United Nations)

As the population grows, the demand for natural resources — clean air, water, energy, minerals, metals and food — also increases. As natural resources are consumed on a large scale, the environment is threatened. Experts say that unless greenhouse gas (GHG) emissions are reduced, the Earth's temperature could increase by 2 degrees Celsius by 2034 or in 10 years. This is beyond the target of 1.5 Celsius that climate scientists prescribe to keep the Earth habitable.