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Scientific Views of Threats to Humanity

by Louise Good

From the poster for “It’s Not a Zombie Apocalypse: Scientific Views of Threats to Humanity”
Background image IR/visible by Jason K. Chu. IR faces courtesy Gordon Squires. Art and design by Karen Teramura.

The pre-Halloween Frontiers of Astronomy Community Event held on October 23 was not for scaredy-cats. No, it wasn’t the presence of ghosts, goblins, or zombies that was scary. It is the dangers faced by our planet and the human race that could give you nightmares.

“It’s Not a Zombie Apocalypse: Scientific Views of Threats to Humanity” began with astronomer Karen Meech giving a brief history—past and future—of our planet. She explained that we live in an era when Earth is neither too hot nor too cold for complex life, including humans, but that this will not last for more than another half a billion years.

Next, Larry Denneau, a software engineer with the Pan-STARRS project, spoke about the possibility of a sizable asteroid hitting Earth. There are about 650,000 known asteroids. Of these, about 9,000 qualify as near-Earth asteroids, and of these 1,300 are “potentially hazardous.” But with Pan-STARRS and other observing programs searching the heavens for these asteroids, we may be able to find those on a collision course with Earth in time to deflect them. It is believed that a large asteroid caused the demise of the dinosaurs about 65 million years ago, but as the saying goes, “The dinosaurs did not have a space program.” Besides, the demise of the dinosaurs ultimately resulted in the rise of mammals, so in a real sense we may owe our existence to that asteroid.

Mike Mottl, a professor in the UH Oceanography Department, spoke about supervolcanoes and something called large igneous provinces (LIPs). He said that the volcano under Yellowstone National Park is potentially the most dangerous on Earth. The 1980 eruption of Mount St. Helens in Washington state blew 1.2 cubic kilometers of pulverized rock into the air. Previous Yellowstone eruptions have spewed hundreds or thousands of cubic kilometers of material into the air. An LIP is a large deposit (more than 100,000 square kilometers) of igneous rocks that is connected to a hotspot, a stationary region in which hot mantle rises to the surface, much like the hotspot that has made the Hawaiian Islands, only much, much larger. LIPs release huge amounts of lava in a very short geological time, resulting in rises in sea level, seawater temperature, and the temperature of Earth’s atmosphere, thereby causing mass extinctions. Fortunately, the eruption of a supervolcano or an LIP does not appear to be imminent.

Rich Gazan of the UH Information and Computer Sciences Department discussed the threat from technology in which people will choose to live a virtual life through technology rather than face life’s real challenges. He sees it starting to happen, with people spending more and more time interacting with screens (television, video games, the Internet, etc.) than with other humans. He fears that “humanity will willingly transform itself into components of a massive biotechnological computer matrix that generates and experiences its own stories, because real life is too hard.”

It got scarier: Biochemist Steve Freeland spoke about the exponential rise in population that has occurred in the last century. So far, our gains in technology have enabled us to raise enough food to prevent widespread famine, but that may not last. There is a good chance that we will exhaust the resources of our planet. He said that one bright spot is that the education and empowerment of women brings down the birth rate and the level of violence in the world.

But the scariest moment came when Mottl replied to a question: He said that the consequences of global warming have consistently been underestimated by scientists and that there is now evidence that the limit of carbon dioxide that Earth can absorb will be reached in 16 years. Reaching this limit could trigger what Mottl calls “irreversible feedbacks,” causing Earth to become significantly warmer, making it unlivable for a significant percentage of its already-huge human population.