There
are concerns that merit serious consideration. Many people worry about
overpopulation and the water and food shortages it may bring. Others
fret about the consequences of a global financial collapse. What about
natural disasters, epidemics, or nuclear war? Could such events bring
about a global catastrophe?
Consider briefly some commonly discussed
doomsday scenarios. Not all threaten to kill everyone on earth, but they
certainly appear to have the potential to bring doom to civilization as
we know it. They include the following.
Supervolcanoes
In 1991, Mount Pinatubo erupted in the
Philippines, killing more than 700 people and leaving some 100,000
homeless. A huge cloud of ash rose 19 miles (30 km) into the sky and
then fell to the earth, burying crops and causing the roofs of buildings
to collapse. Pinatubo and other volcanoes like it cause changes in
climate for several years after erupting.
Super eruptions, such as those that have occurred
in the distant past, would be hundreds of times larger and more
devastating than any eruptions in recorded history and would do far more
damage. Apart from the immediate destructive power, global climate
change would cause crop failure, disrupt food supplies, and lead to mass
starvation.
“Volcanoes kill plants and animals for miles around; supervolcanoes threaten whole species with extinction by changing the climate across the entire planet.”—National Geographic.
Asteroids
Early one morning in 1908, a man was sitting on
the front porch of a trading post in Vanavara, Siberia, when an
explosion flung him from his chair. The heat was so intense that he felt
as though his shirt were on fire. Ground zero for that explosion was
some 40 miles (60 km) away. The blast was caused by an asteroid that was
about 120 feet (35 m) in diameter and weighed approximately 220 million
pounds (100 million kg). After entering earth’s atmosphere, the
asteroid exploded as a result of the pressure and the heat of its
descent. The explosion released energy equivalent to 1,000
Hiroshima-sized bombs and flattened some 800 square miles (2,000 sq km)
of Siberian forest. A larger asteroid, of course, would do much more
damage, generating immense firestorms, which would be followed by
plummeting global temperatures and major extinctions.
“Throughout earth’s history, we have been bombarded by comets and asteroids from space. Impacts happened more frequently in the past, but they will happen again. It is just a matter of when.”—Chris Palma, senior lecturer in astronomy and astrophysics at Penn State University.
Climate Change
Scientists believe that a rise in the earth’s
average temperature, extremes in weather, the melting of ice caps and
glaciers, and the death of coral reefs and important species all point
to global climate change. Though the subject is debated, many hold the
cause to be the burning of coal, oil, and natural gas
Some experts believe that those emissions act
like a greenhouse, slowing the escape of heat from the earth into space
and causing temperatures to rise. Because trees absorb carbon dioxide,
large-scale deforestation may also contribute to climate change.
“If present rates of global warming continue and production of carbon dioxide is not curtailed, many scientists believe the Earth’s average temperature will continue to rise, resulting in wilder and more unpredictable climatic swings and higher ocean levels that could threaten the low-lying coastal areas where much of humanity makes its home.”—A Mind for Tomorrow: Facts, Values, and the Future.
Disease Pandemic
In the 14th century, the Black Death wiped out a
third of the population of Europe in just two years. Between 1918 and
1920, the Spanish flu killed at least 50 million people. Slow methods of
travel impeded the spread of those diseases. However, with the growth
of cities and the ease of international travel today, a similar disease
could rapidly spread across all continents.
Such a pandemic disease could be a natural
occurrence. But there are also growing fears of biological weapons,
man-made diseases. Experts in the field say that a small group of people
who are trained in key disciplines could buy equipment on the Internet
and produce deadly biological weapons.
“Naturally occurring disease remains a serious biological threat; however, a thinking enemy armed with these same pathogens—or with [multidrug-resistant] or synthetically engineered pathogens— could produce catastrophic consequences” —The Bipartisan WMD Terrorism Research Center.
Extinction of Critical Species
Over the past five years, beekeepers in the
United States have lost about 30 percent of their bees each year on
account of colony collapse disorder, a global phenomenon in which entire
colonies of bees abruptly and mysteriously disappear from their hives.
Bees do more than provide us with honey. They pollinate key crops,
including grapes, apples, soybeans, and cotton. We depend on bees.
We also depend on phytoplankton. Without it we
would have no fish. Without worms to aerate the soil, we would have far
fewer crops. The extinction of such key species would result in food
shortage and starvation, leading to violence and riots. Pollution,
overpopulation, overharvesting, habitat destruction, and climate change
contribute to the extinction of animal species perhaps as much as 1,000
times more than natural rates.
“Every year, between 18,000 and 55,000 species become extinct. The cause: human activities.”—United Nations Development Program.
Nuclear War
One nuclear explosion can instantly obliterate a city
“Nuclear weapons remain the gravest and most immediate threat to human civilization. . . . There are still some 25,000 nuclear weapons worldwide . . . Eventually, terrorists will get the bomb.”—Union of Concerned Scientists.