Yet another year is tugging impatiently at the sleeve of closure and within days will be history.

In environmentalist terms, 2002 may be best remembered for summer's U.N. Summit on Sustainable Development held in Johannesburg, South Africa -- though to many observers that Second Earth Summit seemed more circus than circumspection. Clearly a two-week global gathering couldn't possibly yield comprehensive accounting of the environmental problems humanity faces.

What, then, really is the status of our forests and freshwater supplies; our marine ecosystems and urban areas? What have we achieved environmentally in recent years; and what are the biggest challenges remaining?

For those serious about getting up to speed on where we stand, perhaps the most comprehensive and reasonable overview of the state of our planet is "Global Environment Outlook 3," produced under the auspices of the U.N. Environment Programme based in Nairobi, Kenya. This is the third in a series of UNEP state-of-the-environment reports drafted with the cooperation of more than 35 collaborating institutions worldwide. GEO-1 came out in 1997 and GEO-2 in 1999.

"GEO-3 provides an overview of the main environmental developments over the past three decades, and how social, economic and other factors have contributed to the changes that have occurred," states the report.

But why a 30-year perspective, rather than, say, 50 or 20 years? As GEO-3 notes, "The year 1972 stands as a watershed in modern environmentalism. The first international conference on the environment -- the U.N. Conference on the Human Environment -- was held in Stockholm that year, bringing together 113 nations and other stakeholders to discuss issues of common concern."

Personally, as a parent and teacher today, who remembers cleaning a river bank with other junior high school students on the first Earth Day in 1970, this 30-year overview certainly helps to put the environmental change and policy responses in my lifetime into perspective, adding to GEO-3's value as a learning and teaching tool. From land use to the atmosphere, the report offers a balanced overview of what we have done, where it has led us -- and where we are headed.

GEO-3 starts with a succinct look at our environmental ledger, beginning with some good news. "In the 30 years since [1972], the world has made great strides in placing the environment on the agenda at various levels -- from international to local. . . . Decisions made since Stockholm now influence governance, business and economic activity at different levels, define international environmental law and its application in different countries, determine international and bilateral relations among different countries and regions, and influence individual and society lifestyle choices."

Shortfalls, however, remain. "Some things have not progressed. For example, the environment is still at the periphery of socio-economic development. Poverty and excessive consumption continue to put enormous pressure on the environment. The unfortunate result is that sustainable development remains largely theoretical for the majority of the world's population of more than 6,000 million people.

"The level of awareness and action has not been commensurate with the state of the global environment today; it continues to deteriorate," says the report.

For teachers and students in particular, GEO-3 offers an excellent learning tool that can be used directly on the Internet or downloaded and printed out. Comprehensive and accessible, it presents theme-based analyses of socio-economic trends; land use; forests; biodiversity; freshwater, coastal and marine areas; atmosphere; and urban areas -- with each theme viewed from global and regional perspectives. Using the Stockholm conference as a baseline, GEO-3 examines how issues of resource use and abuse have evolved, and how the international community has addressed these issues with varying degrees of success and failure.

However, beyond simply documenting environmental problems, the report is useful for its consideration of how socio-economic trends are inextricably entwined with the environmental problems we face today. To help readers grasp these abstract global issues, GEO-3 categorizes the world into four major "divides" that impact efforts to solve environmental problems. The four are:

"The environmental divide -- characterized by a stable or improved environment in some regions, for example Europe and North America, and a degraded environment in other regions, mostly the developing countries;

"The policy divide -- characterized by two distinct dimensions involving policy development and implementation, with some regions having strength in both and others still struggling in both areas;

"The vulnerability gap -- which is widening within society, between countries and across regions with the disadvantaged more at risk due to environmental change and disasters;

"And the lifestyle divide -- partly a result of growing poverty and of affluence. One side of this divide is characterized by excesses of consumption by the minority one-fifth of the world population, which is responsible for close to 90 per cent of total personal consumption; the other side by extreme poverty, with 1.2 billion living on less than $1 per day."

While not all readers may agree with these classifications and the report's characterizations of each, the divisions remain useful constructs for considering the complex and interdependent nature of environmental problems at a variety of levels, from local to international.

Another feature of GEO-3 that may appeal to teachers is that it offers four potential scenarios "to explore what the future could be," depending on what policy approaches are taken in coming decades. The four are:

* Markets first -- if "values and expectations prevailing in today's industrialized countries" are maintained

* Policy first -- in which "decisive initiatives are taken by governments in an attempt to reach specific social and environmental goals"

* Security first -- which "assumes a world of striking disparities where inequality and conflict prevail"

* Sustainability first -- in which "a new environmental and development paradigm emerges"

For readers convinced that humankind is on its last legs, GEO-3 will appear too calm in its analysis. For those who subscribe to "don't worry, be happy" skepticism, it may seem alarmist. However, balanced reporting, in both tone and structure, is a key goal of GEO-3. For example, the last chapter, titled Conclusions, offers 12 environmental achievements of the past three decades, judiciously followed by 12 environmental challenges we still face, making this section a useful teaching tool on its own.

With so many sources now offering misleading bits and pieces, GEO-3 is an excellent place to begin making sense of the whole global story for the sake of your children, your students -- and yourself.