Green Daily

Disease has traditionally been Mother Nature's most effective way of keeping human populations in check. From black plague to smallpox to tuberculosis, pandemics - massive outbreaks of infectious disease - have killed billions. Science has freed us of many of the plagues that our ancestors knew, but as our population skyrockets, changes the climate, and builds strip malls in parts of the planet where we haven't been before, we're uncovering new threats and reviving old ones at an unprecedented rate.

A fast-moving outbreak of some new disease could kill millions very quickly, like the Spanish influenza pandemic of 1918 that killed between 20 and 40 million people.

The World Health Organization 2007 report on health and security, titled A Safer Future, notes that "Since the 1970s, newly emerging diseases have been identified at the unprecedented rate of one or more per year." They've also identified more than 1100 "epidemic events" around the world since 2002 (an epidemic differs from a pandemic in that it affects a smaller region and fewer people.) Between November 2002 and July 2003, an outbreak of a never-before-seen disease dubbed Severe Acute Respiratory Syndrome (SARS) threatened to become a pandemic, infecting over 8000 people on 4 continents and killing 774 before it was brought under control.

Right now, the illness that's considered by many researchers to be the mostly likely future pandemic is the H5N1 avian influenza virus, or bird flu. An extremely dangerous virus with a high mortality rate, it's thus far only been found in humans who've been in direct contact with chickens or other fowl. However, if a mutation emerged that allowed the virus to jump from human to human, our penchant for jet travel and international migration would send it around the world in days. And that's just one of the diseases that we know about.

Quite a lot. Although the risk of pandemic is real, it's also something that governments take very seriously. The SARS pandemic would have been far worse without international cooperation, and outbreaks of the dreaded Ebola virus draw doctors from around the world to deal with them. Research is ongoing on bird flu and other known threats.

Disast-o-meter rating? 5/10 .

The danger shouldn't be underestimated, but a lot of work is being done to make sure it doesn't happen.

More doom and gloom