Natural Disasters and the Human Factor

WHEN a car is well maintained, it can provide safe transportation. But that vehicle when abused and neglected can be dangerous. In some respects, the same may be said of planet Earth.

In the opinion of a number of scientists, human-induced changes in earth’s atmosphere and oceans have made our planet a dangerous place by contributing to more frequent and more severe natural disasters. And the future looks uncertain. “We’re in the middle of a large uncontrolled experiment on the only planet we have,” said an editorial on climate change in Science magazine.

As mentioned in the preceding article, there have been a number of powerful storms in recent years. Scientists are studying whether this is linked to global warming, which may be providing more energy to storm systems. Changes in the weather, however, may be just one symptom of global warming. Another potentially harmful consequence may already be in evidence.

Rising Sea Levels and Deforestation

According to an editorial in the journal Science, “sea levels have risen 10 to 20 centimeters [four to eight inches] in the past century, and more is in store for us.” How might this be related to global warming? Researchers point to two possible mechanisms. One is the prospect of the melting of land-based polar ice and glaciers, which would add to the volume of the oceans. The other factor is thermal expansion​—as oceans become warmer, their volume increases.

The tiny Pacific islands of Tuvalu may already be experiencing the effects of rising sea levels. Smithsonian magazine notes that data collected on the atoll of Funafuti shows that the sea level there has risen “an average of 0.22 inches [5.6 mm] annually over the past decade.”

In many parts of the world, population growth means more urban sprawl, more shantytowns, and more environmental degradation. These developments may tend to magnify the severity of natural disasters. Consider some examples.

Haiti is an island nation with a high population and a history of deforestation. A recent news report suggested that as bad as Haiti’s economic, political, and social problems may be, nothing threatens the country’s existence more than deforestation. This threat became tragically evident in 2004, when torrential rains caused mud slides that claimed thousands of lives.

Time Asia points to “global warming, dams, deforestation and slash-and-burn farming” as exacerbating factors in the natural disasters that have plagued South Asia. At the other extreme, deforestation can worsen drought by causing soil to dry out more quickly. In recent years, droughts in Indonesia and Brazil have paved the way for record-breaking fires in forests that are normally too wet to burn.

Again, however, the scale of such disasters hinges to some extent on the human element. One factor is population density in high-risk areas. “Nearly half the world’s big cities now lie in areas of seismic risk,” says author Andrew Robinson. Another factor is buildings​—the materials used and the structural quality. The adage, “Earthquakes don’t kill people; buildings do,” is all too often proved true. But what choice do people have when they are too poor to build earthquake-resistant structures?

Fortunately, volcanoes often give advance warning of an eruption. Such was the case with Mount Pelée on the Caribbean island of Martinique in 1902. An election was imminent in nearby St. Pierre, however, and politicians encouraged the people to stay, despite the ash, sickness, and fear that pervaded the city. In fact, most shops had been shut for days!

May 8 was Ascension Day, and many people went to the Catholic cathedral to pray for deliverance from the volcano. That morning, shortly before 8:00 a.m., Mount Pelée erupted, venting a searing mass of pyroclasts​—ash, cinders, obsidian, pumice, and superheated gas—​that ranged from 400 to 900 degrees Fahrenheit [200-500°C]. Hugging the ground, the resulting dark cloud of death rushed down the mountain, overwhelmed the city, killed almost 30,000 people, melted the church bell, and set fire to the ships in the harbor. It was the deadliest eruption of the 20th century. Yet, it would not have been so deadly if the people had heeded the warning signs.

Will Natural Disasters Increase?

In their World Disasters Report 2004, the International Federation of Red Cross and Red Crescent Societies states that during the past decade, geophysical and weather-related disasters have increased by over 60 percent. “This reflects longer-term trends,” says the report, which was published before the catastrophic December 26 tsunamis in the Indian Ocean. To be sure, if populations in high-risk areas continue to climb and forests continue to decline, there is little cause for optimism.

Additionally, many industrialized countries continue to pump ever more greenhouse gases into the atmosphere. According to an editorial in the journal Science, procrastinating on emissions reduction “is like refusing medication for a developing infection: It guarantees that greater costs will have to be paid later.” Pointing to those costs, a Canadian report on disaster mitigation stated: “Climate change can be argued to be the most pervasive and far-reaching environmental issue ever dealt with by the international community.”

At present, however, the international community cannot even agree on whether human activities contribute to global warming, let alone how to manage it.