Ars Technica reports: A new report published by the Organisation for Economic Co-Operation and Development paints a grim picture of the world in 2050 based on current global trends. It predicts a world population of 9.2 billion people, generating a global GDP four times the size of today’s, requiring 80 percent more energy. And with a worldwide energy mix still 85 percent reliant on fossil fuels by that time, it will be coal, oil, and gas that make up most of the difference, the OECD predicts.

Should that prove the case, and without new policy, the report warns the result will be the “locking in” of global warming, with a rise of as much as 6° C (about 10.8° F) predicted by the end of the century. Combined with other knock-on effects of population growth on biodiversity, water and health; the report asserts that the ensuing environmental degradation will result in consequences “that could endanger two centuries of rising living standards.”
[…]
The report predicts that, as a direct result of increased energy consumption, there will be a 70-percent increase in energy-oriented carbon dioxide emissions, and an overall increase in greenhouse gas emissions of 50 percent. This would correlate to a rise in global average temperature between 3° C and 6° C above preindustrial levels.

Air pollution will overtake contaminated water and lack of sanitation as the prime cause of premature mortality across the globe, potentially rising to 3.6 million deaths per year—mostly in China and India. Death rates caused by ground-level ozone among OECD countries are projected to be among the world’s highest, thanks in part to the aging, urbanized populations.

But population growth has more direct effects upon the environment. The world’s natural resources are set to undergo unprecedented strain. Water demand is projected to grow by 55 percent by 2050 (including a 400-percent rise in manufacturing water demand), when 40 percent of the global population will live in “water-stressed” areas. The report identifies groundwater depletion as the greatest threat to both agricultural and urban water supplies. Nutrient-pollution of water sources is projected to further deplete aquatic biodiversity. And though the number of people with access to an “improved” water source should increase, the report projects that by 2050, 1.4 billion people will be without basic sanitation.