So far, science has described more than 2 million species, and millions more await discovery. 

While species have value in themselves, many also deliver important ecosystem services to humanity, such as insects that pollinate our crops. 

Meanwhile, as we lack a standardized system to quantify the value of different species, it is too easy to jump to the conclusion that they are practically worthless. 

As a result, humanity has been quick to justify actions that diminish populations and even imperil biodiversity at large. 

In a study, published in the scholarly open-science journal Research Ideas and Outcomes, a team of Estonian and Swedish scientists propose to formalize the value of all species through a conceptual species 'stock market' (SSM). 

Much like the regular stock market, the SSM is to act as a unified basis for instantaneous valuation of all items in its holdings. 

However, other aspects of the SSM would be starkly different from the regular stock market. 

Ownership, transactions, and trading will take new forms. Indeed, species have no owners, and 'trade' would not be about transfer of ownership rights among shareholders. 

Instead, the concept of 'selling' would comprise processes that erase species from some specific area—such as war, deforestation, or pollution. 

Conversely, taking some action that benefits biodiversity—as estimated through individuals of species—would be akin to buying on the species stock market. 

Buying, too, has a price tag on it, but this price should probably be thought of in goodwill terms. Here, 'money' represents an investment towards increased biodiversity. 

"By rooting such actions in a unified valuation system it is hoped that goodwill actions will become increasingly difficult to dodge and dismiss," adds Kõljalg.

The study proposes that the SSM is orchestrated by the international associations of taxonomists and economists.