'There would be no natural disasters if it were not for humans:' Understanding our planet's hazards, risks
For 4.5 billion years, Earth has remained a dynamic planet, governed by powerful physical forces.
As inhabitants, these natural events can provide a source of great beauty, awe-inspiring wonder or terror and despair depending on the circumstances of Mother Nature’s influence.
It is only when human life and property are threatened or negatively impacted by nature do we view these natural events as “natural hazards” and “natural disasters,” according to Tulane University Professor Stephen Nelson.

This is an aerial view of a flooded neighborhood in New Orleans, Louisiana, on Thursday, Sept. 1, 2005, after Hurricane Katrina passed through the area. (AP Photo/Phil Coale)
Many of the natural events humans have come to view as disastrous are the same processes that have given rise to Earth’s varied landscapes, oceans and atmosphere.
“There would be no natural disasters if it were not for humans. Without humans, these are only natural events,” Nelson said on his university web page.
Variables for Earth’s habitability range from the volcanic activity, Earth’s density and geologic processes, the planet’s proximity to the sun and even a moon of perfect size and distance that limits Earth’s wobble, preventing vast fluctuations in temperature and extreme weather events.
Nelson, who teaches a course on natural disasters, said that a different perspective is required when assessing the hazards and risks associated with natural events occurring on Earth.
Natural hazards are natural threats that negatively affect humans, while natural disasters are the effects of these hazards that bring harm to human life or property, he said.
Most of the hazards around the globe are geologic in process including earthquakes, volcanic eruptions, landslides and subsidence. Meteorological hazards include the threat of powerful storms and flooding.
Biological hazards can include infectious disease and insect infestations, while other hazards can be cosmic in origin like asteroid impacts and solar storms.
As humans, risk is part of our relationship with the planet and its processes.

A car and debris smashed against a tree along Hot Springs Road in Montecito, Calif. Heavy rain brought flash flooding and mudslides to the area in Montecito, Calif. on Tuesday, January 9, 2018. At least five people were killed and homes were swept from their foundations Tuesday as heavy rain sent mud and boulders sliding down hills stripped of vegetation by a gigantic wildfire that raged in Southern California last month. (AP Photo/Daniel Dreifuss)
“There’s a risk in driving your car,” Nelson said, adding that this risk does not stop most of us from driving.
While the risk of being caught in the grip of a natural disaster can never be eliminated, understanding the potential hazards is key.
In areas that have undergone catastrophic natural disasters historically or areas that have geologic evidence of powerful events, humans sometimes ignore the warning signs and continually rebuild in these geographic regions.
“This is one of the things that puzzles me,” Nelson said, referring to continual reconstruction in areas prone to frequent severe weather and geologic events. “A lot of times it may be for economic decisions, and if the economic benefits outweigh the risk, we may tend to ignore it.”
Nelson said that understanding the risk is the first step in mitigating the impact a natural hazard can have on life and property.
“I think education is a big factor,” he said.
For example, if you are on a beach and feel a strong earthquake, rather than waiting for a warning, immediately seeking higher ground could save your life from a possible tsunami.
“If you take that simple step, you have already reduced your risk,” he said.
Construction standards should also be taken into account, Nelson said.
Improving structures for environmental hazards can be done by homeowners or regulated by state or local authorities through building codes and could save lives.
In many cases, residents must assess their own well-being and how to ensure the protection of their property as certain construction methods may not be required, even in areas prone to natural disasters like hurricanes, tornadoes or frequent flooding.
Building codes in the United States are not geared for extreme weather events such as tornadoes, Haag Engineering Co. Structural Engineer and Meteorologist Tim Marshall said in a 2014 AccuWeather report.
The country lacks building codes for tornadoes because they are isolated, and the general population may not witness one in a lifetime, Marshall said.
Nelson, who built his home prior to Hurricane Katrina in 2005, said he had the contractor employ the use of hurricane clips to better secure his roof against high wind gusts for an additional cost of $400. That building requirement that would be added to the area’s code a decade later.
While codes serve new construction and future construction, older structures are hard to upgrade, Marshall said. Storm shelters are likely a better investment for those who own older homes, he added.
Another factor Nelson said must be considered is geologic time in comparison to a human lifetime. Many natural hazards may be ignored because they occurred long before human record keeping, and geologic evidence indicates larger intervals of time between events.
However, the potential for disaster is still present.
“A different perspective is needed when we look at these events,” he said.
For example, while 20,000 years since a major eruption may seem like a long time when compared to the human experience, it is in fact brief considering Earth’s lifetime.
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For more safety and preparedness tips, visit AccuWeather.com/Ready.
