First, I may mention a few fascinating possibilities which make great topics for “disaster porn” (ala Sci-Fi Channel), but which are not at all likely to occur in our century:
- An asteroid or comet
collision could one day wipe out mankind, but the chance of a very
bad asteroid or comet collision occurring in this century is very
low. One need merely consider that we haven't had such a collision
during the roughly 5000 years of recorded history, so the chance of
it occurring in the remainder of this century is much less than 2%.
- There is a gigantic
volcanic time-bomb sitting underneath Yellowstone National Park, and
scientists think the last time it erupted it pretty much buried
North America in ash and dust. It could do the same thing again, as mentioned here, but
thankfully the previous eruption was more than 600,000 years ago. So
the chance of such a disaster occurring in our century is much less than
- The widely discussed
possibility of a “gray goo” disaster caused by an uncontrollable
reproduction of nanotechnology is probably something that has a low
chance of happening in this century. Nobel Prize winner Richard
Smalley argued that there are technical reasons why he don't have to
worry about this possibility.
- There is very little
chance that before the year 2100 robots will take over the world or
make us slaves or get rid of us. While there will be fantastic leaps
in robot hardware, you need equally great leaps in software before
robots are a huge risk to mankind; and software is only increasing
gradually rather than exponentially.
1. A City-Busting Hurricane
Global warming is slowly increasing the temperature of seawater, and it is warm seawater that leads to hurricanes. The National Oceanic and Atmospheric Administration says, “It is likely that greenhouse warming will cause hurricanes in the coming century to be more intense globally and have higher rainfall rates than present-day hurricanes.”
Unfortunately, many of the world's largest cities are in danger from this possibility. Hurricanes cause storm surges that temporarily and locally raise sea levels. When you combine such surges with sea levels that may already be elevated because of global warming, the chance of devastation is very high. The devastation in New York caused by Hurricane Sandy and the similar devastation in New Orleans may be just a foretaste of far worst disasters in our century. Before 2100 we will probably see at least one major city more or less wiped out by a hurricane.
2. A City-Busting Nuclear Explosion
Despite the progress that has been made in reducing Cold-War worries about nuclear war, there is a still a very large chance that at least one city will be destroyed by a nuclear bomb before the year 2100. Even though the United States and Russia have reduced their nuclear arsenals, they each still have about 2000 active nuclear weapons. India and Pakistan each have about 100 nuclear weapons. The continued risk of nuclear war was highlighted by a recent announcement by the Bulletin of Atomic Scientists that it was keeping its Doomsday Clock (a warning of global risk) set at five minutes before midnight. Many of the US and Russian nuclear weapon systems are very old, built using technology that does not meet modern standards of reliability. The risk of an accidental launch or detonation is significant.
Besides the danger of a conventional nuclear war, there is the ongoing risk of nuclear terrorism. Outside of the world's nuclear bombs is enough highly enriched uranium and plutonium to make 40,000 additional nuclear weapons. Much of this exists in places in less than ideal security. If terrorists were to steal only a softball-sized amount of this highly enriched uranium, it would then be fairly easy for them to construct a homemade nuclear bomb. We are very lucky that no city has yet been lost in a mushroom cloud.
3. A Mega-drought
Currently California is facing the worst drought in its 163-year history. A few years ago, Texas faced a similar drought. These are probably just like tremors warning us of the earthquakes to come. This study projects future droughts using a Palmer Drought Severity Index, in which bigger droughts have a larger negative number. The worst drought ever recorded had a Palmer Drought Severity Index of -3 or -4. But the study projects that by the year 2100 some parts of the United States will see droughts with a Palmer Drought Severity Index of -8 or -10, more than twice as bad as the worst drought ever recorded. The same study forecasts that by the year 2100 some Mediterranean areas will face droughts with a Palmer Drought Severity Index in the -15 or -20 range, four or five times worse than the worst ever recorded.
4. An Energy Crunch
By an energy crunch I mean a gap between the amount of energy the world has and the amount of energy the world needs for its current economic activities. There is a huge risk of a gigantic energy crunch in this century, because we have limited supplies of fossil fuels. It is predicted that global oil production will peak within a few decades. It is also predicted that global coal production will peak in this century, probably a few decades later than oil production will peak. The result may be a catastrophe even worse than global warming, one that leaves millions shivering or sweating in a world where electrical power is unreliable. In this study a Cal Tech scientist cites a forecast that 90% of global fossil fuels will be exhausted by 2067.
5. Mass Famine
There are four reasons why a mass famine is a large possibility before the year 2100:
large possibility of terrible droughts, discussed above.
global stressing of available water supplies, which will make it
harder to irrigate crops.
large possibility that global oil supplies will plunge long before
the year 2100, because of the depletion of this limited resource. Oil is
a major factor in agricultural production, being used to transport
food and make fertilizers.
fact that global population will have greatly increased, rising to
as high as ten billion.
6. Global Depression or Economic Collapse
The global economy is something that has grown erratically, in fits and starts, with very little previous planning or design. No one ever designed the global economy to last a thousand years, and there is no reason to be very confident that it can survive something such as a gigantic energy crunch, particularly if such a disaster is combined with some of the other disasters discussed here. In particular, the global economy has a strong tendency to rely on debt, and once things start going wrong, many people lose the ability to repay debts. We saw a tremendous ripple effect caused when many people couldn't repay their debts during the 2008 economic crisis. Something similar could happen to a degree that could be ten times worse, and it bring down the whole economy like a collapsing house of cards. The result would at best be a global depression like we saw in the 1930's, and at worst a global economic collapse. The chance of such a thing seems worse when one considers that after the 2008 financial crisis, the world's nations patched on a lot of band-aids and used "extend and pretend" to muddle through, rather than making the hard choices needed to reduce the risk of similar problems in the future.
7. A Global Pandemic
The risk of a global pandemic or plague is described in my previous How to Have a Pleasant Pandemic. The risk is very substantial because of three main factors: (1) global warming will increase the risk from certain types of diseases; (2) increased jet travel increases the chance of diseases spreading around the world; (3) there is a very substantial risk that mankind will be inflicted by some new disease deliberately cooked up in a laboratory by some malevolent party.
In regard to the third of these factors, consider that gene-analysis technology that used to cost millions of dollars is now available in desktop devices for a few thousand dollars. Technology leaps such as that may in a few decades make it so that any Tom, Dick, or Harry can whip up a new virus or bacteria in his garage, or genetically turbocharge an existing type of germ. Once that happens the risk of a global pandemic will rise much higher.
So that is my list of the seven likeliest disasters of this century. If it leaves you depressed, please read my vastly more optimistic post The 8 Luckiest Things That Could Happen in the Future.