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.
