JULY/AUGUST 2019. DISCOVER 75
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Hurricanes and Climate Change
Hurricanes are powered by warm water, so it seems obvious that climate change should
lead to more — and more powerful — storms. That’s half-right, according to researchers.
While they predict the number of intense hurricanes will increase as the oceans warm,
it’s likely the total number of hurricanes will actually decrease in the future.That’s because hurricane formation relies on a temperature difference between the
warm oceans and cooler upper atmosphere. A warmer atmosphere means more uniform
temperatures overall, and fewer hurricanes.
But, despite fewer total storms, the damage that results from more powerful ones is
likely to continue to grow. Not only will storms be stronger and bring more precipitation,
but coastal development has continued unabated, meaning there’s more for a hurricane
to destroy.
Notable Hurricanes
Strongest storm:
Typhoon Tip in
1979 had the
lowest recorded
barometric
pressure
(870 millibars),
meaning it had
the strongest-
ever low-pressure
system fueling it.
Worst Atlantic hurricane
season: A record-breaking 28
tropical storms were recorded
in 2005, 15 of which became
hurricanes. Five were bad
enough to have their names
retired; four of those reached
Category 5: Emily,
Katrina, Rita and
Wilma.
Deadliest in U.S.:
The Galveston
hurricane in
1900 claimed
6,000 to 12,000
lives.
Deadliest in the world:
Galveston’s got nothing on
the 1970 Bangladesh cyclone,
which killed 300,000. This
extreme devastation was
mostly because of storm
surge, which was exacerbated
by high tide and geography.The storm also destroyed
9,000 ocean fishing boats in a
region heavily dependent on
fish for food.
Strongest winds: In 1996,
Tropical Cyclone Olivia’s winds
peaked at over 250 mph.
Most rainfall in one day:
Hurricane Denise was the
wettest, dumping 71.8 inches
of rain in a 24-hour period
in 1966.
Five Categories of Mayhem
Hurricanes today are rated on the Saffir-Simpson scale, which places them into five
categories according to wind speed. But the scale has been criticized for not accounting
for rainfall totals, which can cause significant damage. Some atmospheric scientists
have lobbied for a sixth category for even stronger storms, but there’s no official
consensus on the idea.
74-95 mph (Hurricane Isaac in 2012): Damage to roofs and windows. Shallow
trees might be uprooted. Power outages are likely.
96-110 (Hurricane Arthur in 2014): Flying debris poses a substantial risk to people
and livestock. Mobile homes likely sustain heavy damage, and unreinforced
masonry walls can tumble. Widespread power outages.
111-129 (Hurricane Otto in 2016): Even well-built homes can suffer extensive
damage, while older metal and brick buildings might topple. Most high-rise
buildings will have shattered windows, and blackouts could last for weeks.
130-156 (Hurricane Harvey in 2017): Very high risk from flying debris. Most
mobile homes and poorly constructed homes will be destroyed, and even strong
houses could lose roofs or walls. Trees will be snapped or uprooted, and power
outages might last for weeks.
157+ (Hurricane Maria in 2017): Significant number of houses and buildings
destroyed. Windows will pretty much disappear; trees, signs and power polesannihilated; roofs will most likely be torn off. Power and water outages could
last months.
The Great
Hurricane of
1780 killed at least
24,000 in the Lesser
Antilles, and decimated
British and French fleets
concentrated there
for the American
Revolution.
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The Florida Panhandle
faced major destruction
in 2018 after Category 4
Hurricane Michael hit.