PARIS, France - From the food we eat to the air that we breathe, Nature not only provides mankind with the means to live but also the services to thrive.
Ahead of a major biodiversity summit in Paris expected to outline in the starkest terms yet the threat humans pose to Earth's natural habitats and species, here is a look at what Nature does for us.
ON OUR PLATE
One of the main unseen roles played by Nature comes in the form of pollinating insects.
As much as three quarters of all food produced globally relies on insects to pollinate the crop -- an industry upon which 1.4 billion people rely for income, according to one study.
Yet faced with global temperature increases caused by man-made emissions and poisoned by blanket pesticide use, insects are dying en masse.
This has a cascading effect up the food chain -- birds, lizards, and frogs that eat bugs are also dying out. In just 30 years, Europe has lost 80 percent of its insect population leading to the disappearance of some 400 million birds.
In addition, the erosion of coral reefs due to warming seas imperils as much as 30 percent of all marine species, including the fish that half a billion people rely on to feed themselves.
IN THE MEDICINE CABINET
Around half of the active ingredients in commercial medicines derive from plants or animals.
Starfishes, sea urchins, and periwinkles are just three of the myriad species known to have anti-carcinogenic properties, while molecules from marine worms have proven crucial in preserving skin grafts.
But the health benefits of simply living near Nature -- reducing allergies, alleviating chronic physical, and mental conditions -- might outweigh those provided by any drug.
One US study of 100,000 people over eight years showed those who lived within 250 meters of a green space were 12 percent less likely to die than those who didn't.
Four billion people rely primarily on natural medicines for their healthcare, and 70 percent of drugs used for cancer are natural or bio-inspired, according to a draft report to be vetted at the Paris meeting.
Plants and micro-organisms play a vital role in providing humans with clean water for drinking and crop production, sucking out dangerous particles from rainfall and sanitizing groundwater.
According to biologist Gilles Boeuf, "no waste treatment plant can ever be as good as a living swamp" for clean water production.
AIR WE BREATHE
Forests and oceans absorb around half of all man-made greenhouse gas emissions annually, offsetting the worst excesses of global warming and providing us with clean air to breathe.
But as emissions continue to rise and the levels of greenhouse gases in the atmosphere hit their highest in three million years, scientists warn that Earth's natural CO2 absorption ability may not be able to keep pace.
Plants are also a powerful filter against air pollution in cities. A recent study in Shanghai showed that its green spaces were capable of capturing 10 percent of dangerous fine particles.
Another study, from 2008, showed a fully-grown tree can sequester as much as 20 kilograms of particulate matter.
Much research has tried to evaluate the worth, in monetary terms, of the services rendered to us by Nature.
One estimate puts Nature's worth at $125 trillion each year, corresponding to roughly a half of global GDP.
Insect pollination alone is worth $200 billion per annum.
One study from 2010 put the cost of biodiversity loss at between $1.35-3.1 trillion annually.