The Changing Earth: Environmental Trends Since Rio
The first United Nations Conference on Sustainable Development, the Rio Earth Summit in 1992, addressed the state of the environment and sustainable development. The Rio Earth Summit resulted in several milestone outcomes, including treaties on climate change, biodiversity and desertification, and a plan of action (known as ‘Agenda 21’ and adopted by over 178 governments to address human impacts on the environment at all scales). Ten years later, a second summit in Johannesburg (the World Summit on Sustainable Development) confirmed the international commitment to the ambitions identified at the Rio Summit.
In 2012, the United Nations Conference on Sustainable Development, or Rio+20 Earth Summit, aimed to renew the political commitment to sustainable development, review progress and identify implementation gaps, and address new and emerging challenges. Earth and its human population have seen remarkable changes in the 20 years since Rio – technologically, economically, socially and environmentally. Until very recently in the history of Earth, humans and their activities have not featured as a significant force in the dynamics of the Earth System. Today, humankind has begun to match and even surpass the forces of nature in changing key Earth System processes.
Over the past two centuries, both the human population and the economic wealth of the world have grown rapidly. These two factors have increased resource consumption significantly, evident in agriculture and food production, industrial development, energy production and urbanisation. In the 20 years since Rio, the world’s population has grown from 4.5 billion to 7 billion people – an extraordinary increase of more than half in less than a generation. All share basic human needs, such as the demand for water, food, shelter, community health and employment. The ways in which these needs are met are critical determinants of the environmental consequences at all scales. In the developed world, affluence and the demand for consumer goods for entertainment, mobility, communication and a broad range of goods and services are placing significant demands on the global environment and natural resources.
The nature of the changes now occurring simultaneously in the global environment, their magnitudes and their rates are unprecedented in human history, and probably in the planet’s history.