By EDWARD O. WILSON

IN one sense we know much less about Earth than we do about Mars. The vast majority of life forms on our planet are still undiscovered, and their significance for our own species remains unknown. This gap in knowledge is a serious matter: we will never completely understand and preserve the living world around us at our present level of ignorance. We are flying blind into our environmental future.

Since the Swedish naturalist Carl Linnaeus inaugurated the modern system of classification two and a half centuries ago, biologists have found and given Latinized names to about 1.8 million species of plants, animals and microorganisms — an impressive number but probably 10 percent or less of the total. Rough estimates of the number of species that remain to be discovered range from 10 million to more than 100 million.

But a new project in biology, an ambitious effort to create a vast new electronic database of known species, should make it possible to discover the remaining 90 percent of species in far less than 250 years, perhaps only one-tenth that time, a single human generation. On May 9 of this year, a consortium of institutions from Harvard and the Smithsonian to The Atlas of Living Australia began compiling The Encyclopedia of Life, which one day will provide single-portal access to all knowledge of living organisms.

Why bother making such an effort? Because each species from a bacterium to a whale is a masterpiece of evolution. Each has persisted, its mix of genes slowly evolving, for thousands to millions of years. And each is exquisitely adapted to its environment and interlocks with a legion of other species to form the ecosystems upon which our own lives ultimately depend. We need to properly explore Earth’s biodiversity if we are to understand, preserve and manage it.

Recent advances in technology and science have made it possible to compile, and enlarge, The Encyclopedia of Life. The accelerating pace of nucleic acid sequencing allows scientists to read any organism’s complete genetic code. A single viral or bacterial species can be decoded in hours, making the immense world of microorganisms — the “dark matter of the biosphere” — at last open to swift exploration.

The Encyclopedia of Life will contain an infinitely expandable page for each species, with links as needed, providing whatever is known of the species from its DNA to its place in the environment and its importance to humanity. It will ensure that existing knowledge is freely available to anyone, everywhere, at any time. And, most important, it will accelerate the discovery of the unknown species.

This should deliver immediately practical benefits. The discovery of wild plant species adaptable for agriculture, medicine and other uses, for example, will be speeded up, while disease-causing bacteria and viruses may be discovered and controlled before they can cause widespread harm.

It is crucial that we move quickly, as ecosystems and species are disappearing — due to habitat destruction, pollution, overpopulation and excessive hunting and fishing, as well as invasive species like fire ants, zebra mussels, bacteria and viruses. Human-caused climate change alone could eliminate a quarter of species during the next five decades.

What will we and future generations lose if a large part of the living environment continues to disappear? Huge potential stores of scientific information will never exist. Novel classes of pharmaceuticals and future crops will be thrown away. Ecological services like water purification, soil renewal and pollination — which are approximately equal to the world gross domestic product, and given away by natural ecosystems — will be diminished. Environmental stability will be harder to achieve.

The Encyclopedia of Life is science with a deadline. We have set a goal to organize and enter all basic information on the 1.8 million known species within 10 years. This is an ambitious timetable, but it is important to establish the project as big science, on par with the human genome project — a priority of biology that is ultimately supported with both government and private financing and with the participation of scientists worldwide. Even a partial success will be of incalculable value to humanity, and to the rest of life, for all time.