In his interview with Bill Moyers, David Suzuki discusses the question of what humans are doing to our air, our soil, and our water. He points out that the consequences of our actions are not yet clear, but that undoubtedly, future generations will see the effects of environmental stress. In his most recent television series, THE SACRED BALANCE, Suzuki discusses how human beings are intimately connected to all life processes on Earth.
One of the problems many scientists attribute to human activity is global warming. A study by the JOURNAL IN GEOPHYSICAL RESEARCH published in January 2002 showed that human activity has affected the Earth's surface temperature during the last 130 years, and that the shift is not over. While Earth's global temperature during the last ice age, more than 15,000 years ago, was only 3 to 5 degrees Celsius (5 to 9 degrees Fahrenheit) cooler than it is now, northern hemispheric temperature may increase by up to 3.5 degrees Celsius (6.3 degrees Fahrenheit) during the next century alone. On the Environmental News Network, a section on Global Warming and Climate Change expresses the fears of some scientists, warning:
More frequent and extreme weather events can be expected, including floods, heat waves, windstorms, droughts and disruption in water supplies. As a result, serious diseases like malaria and yellow fever will spread. Natural resource industries such as agriculture, fishing and forestry will be impacted. As polar ice caps melt and sea level rise, entire island nations will disappear. Coastal flooding with leave hundreds of thousands homeless mostly in poor, developing countries.
Other affects of human behavior on the Earth are so profound that they are visible from space. Photographer Emmet Gowin has been taking the measure of the human footprint on the earth. His stunning aerial photographs appear in a NOW photo essay, Changing the Earth.
In addition, NASA's Visible Earth is a searchable directory of images, visualizations, and animations of the Earth. And NATIONAL GEOGRAPHIC presents a continuing series on satellite imagery called Eye in the Sky, which discusses human impact in relation to floods and dams, ozone and pollution, deforestation and desertification, and overpopulation with vivid graphic support.
Global city lights: Marc Imhoff and a team of researchers at NASA’s Goddard Space Flight Center use a method of mapping urbanization on a countrywide scale by using satellite images of the light cities generate at night to measure the effects of urbanization on the biological productivity in the U. S. and other countries around the world.
NOW's coverage of the World Summit on Sustainable Development in Johannesburg, South Africa in August 2002 includes a briefing on critical issues discussed by the world's leading scientists, with facts and figures on Population and Development, Poverty and Hunger, Health, Energy, Water, and Genetic Diversity.
The following web sites offer more opportunities to track the extent of human impact on our natural resources:
Water Resources of the United States
Water is essential for life. The U.S. Geological Survey (USGS) operates in every State with the goal to provide water information through publications, data, maps, and applications software. One of the features of the site is the Waterwatch, including a "real-time streamflow" map tracking short-term changes (over several hours) in rivers and streams.
Human Impacts on the Landscape
Over the last 150 years, humans have had a large impact on the landscape of the southwestern United States. Agriculture, forestry, and urbanization have modified the land and diverted its resources for human use. Population growth has accelerated in the last few decades, and the increasing number of people may both expand these impacts and make the landscape more vulnerable to climatic variations. This site, also from the USGS provides a list of issues and discussion topics by linking to articles and reports.
After much careful study, environmental scientists have determined that the presence, condition, and numbers of the types of fish, insects, algae, and plants can provide accurate information about the health of a specific river, stream, lake, wetland, or estuary. These types of plants and animals are called biological indicators. This site from the EPA studies the stress on bioindicators to understand current conditions, changes over time, and cumulative effects on the nation's waters.
Population and the Planet
This site explores population issues in considerable detail, asking the question, "Who Cares About Population, Anyway?" in an introductory chapter. Also featured are a "60 Second Tour," and chapters exploring the history of world population, key trends and indicators, the effect of population on the environment, economy, and society, and much more.
United Nations Division for Sustainable Development
The Division for Sustainable Development is responsible for servicing the Commission on Sustainable Development for follow-up of the implementation plans developed during the World Summit on Sustainable Development.