There are almost 8 billion people in the world, that is 10x more than before the Industrial Revolution (only about 250 years ago). The world economy is producing a gross world product (GWP) of $90 trillion a year and it is growing rapidly but it is also highly unequal in its distribution of income within and between countries. Almost 1 in 7 people live in extreme poverty, that is about 1 billion people worldwide that cannot meet basic living needs!
Poverty is not only a lack of adequate income it means also lack of access to basic health services, access to electricity or gas, safe drinking water, sanitation, clothing and safe shelter, education, some of the basic human rights. With the growing population and vast economy output, humanity puts a massive strain on earth’s ecosystem. The very one we need to survive and thrive. We simply cannot continue along the business as usual path. We need to establish the: safe operating limits for the planet; planetary boundaries: climate change, ocean acidification, ozone depletion, the nitrogen cycle, the phosphorus cycle, global freshwater use, change in land use, loss of biodiversity, aerosol loading, chemical pollution (poisoning air and water).
The purpose of Sustainability and Sustainable Development is to understand how do the: economic, social, environmental, political, cultural factors fit together and to set goals on how to make the world prosperous, fair and environmentally sustainable. The world is a fascinating, complicated, interconnected organism, we need to try to understand it and help to improve it.