Most of our experience is local, related to the neighbourhoods and communities where we live. We have our local fishery and forestry issues, our regional airport projects, and the nearby hydroelectric dams that we maintain and upgrade. None of this seems to be of global significance — until we expand the horizon of our perspective.

The dams and diversions built on the Campbell River system were part of a world-wide trend that now obstructs the flow of almost every river on the planet. The 5,000 dams of 15 metres or higher that blocked the world’s rivers in 1950 have now increased to 45,000. This represents an average completion rate of two large dams per day for half a century. Hundreds of thousands of smaller dams are uncounted. Fewer than five of the world’s major rivers now flow unimpeded to the sea — some no longer even reach the sea. Countless river-dependent fisheries and ecologies have been dramatically compromised.

We cheer the new flights that come to our regional airports. The convenience of easier access to the rest of the world seems innocent enough. But these few extra landings and takeoffs add to the 3.2 million flights in 2006 that moved about 400 million people to hundreds of destinations around the planet, flights that produced more than twice the total carbon dioxide output of the billion people living in India.

Should we be concerned about the release of a few toxins into the environment? The chemicals seeping from just the industrial waste dumps on the Niagara Peninsula, if they were fed to children, contain enough toxic material to cause developmental defects in every child on the planet for the next million years. The amount of PCBs contained in all the electrical transformers manufactured is sufficient to contaminate all the world’s fish. The release of mercury into ecosystems, primarily from burning coal, is now accomplishing this dark task — pregnant women and small children are currently advised to eat limited quantities of some marine fish.

And how is the local fishing? If you are planning a sunny summer of stalking salmon on the ocean, you might be interested to know that your single boat will join about 4 million industrial-sized vessels that are removing close to 100 million tonnes of fish each year from the same ocean you will be fishing. Worldwide stocks of large fish have been reduced by about 90 percent. Many key species are now close to commercial extinction. As a simple measure of the enormous scale of catch and consumption, house cats in America are fed 2.9 million tones of fish each year.

The Earth Policy Institute is thinking about what all this means. The most recent report by its scientists and economists provides a fair snapshot of the health and sustainability of the natural ecosystems that support human life on our planet. “More than half the world’s people depend directly on croplands, rangelands, forest and fisheries for their livelihoods,” notes its report (Guardian Weekly, May 4-10/07). Since environmental deterioration translates into economic decline, the Institute is concerned that this erosion of ecological health should be corrected while we can still afford to do so. In keeping with this objective, it has calculated our needs, suggested remedies and estimated the cost in dollars.

Restoring global fisheries will require “a worldwide network of marine reserves” covering about 30 percent of the oceans’ surface. This would cost about $13 billion per year. But it would eventually establish a sustainable global fishery. Given our present practices, our oceans will be empty of fish by 2050.

For our forests, the Institute reckons we will need to remediate 30 million hectares and add an additional 55m hectares to meet a growing demand for forest products. “Anchoring soils and restoring hydrological stability will require a further 100m hectares.” Making this a 10-year project would cost about $6 billion per year.

Topsoil conservation is crucial because it is presently being lost to erosion and unsustainable farming practices faster than it is being created. About 10 percent of the world’s cropland needs to be replanted in grass and trees in order to save and rebuild supplies. Soil-saving farming practices have to be implemented. The total cost of this topsoil protection plan would be about $24 billion per year.

The protection of rangelands from desertification and deterioration due to overgrazing is a 20-year restoration project estimated to cost $180 billion. The yearly investment would be $9 billion.

Wildlife protection will require about $25 billion per year to enhance existing parks, with $6 billion more for additional reserves. This annual cost of $31 billion will help to secure some ecological balance and maintain a sampling of species diversity.

Fresh water problems must be addressed. Water tables are dropping in almost all crucial agricultural areas and water shortages are rising almost everywhere. Food production is threatened in many places and mass starvation would likely trigger global political instability. Improved irrigation techniques and new technologies will require about $10 billion per year.

None of this will directly address carbon dioxide emissions and the resulting threat of climate change. That’s another investment we will have to make if we want a viable future. But the Institute’s estimate of $93 billion per year will buy us some semblance of ecological sanity.

By all local measures, $93 billion seems like a lot of money — until we realize that the world’s annual military spending is $1,200 billion.