The alarming link between climate change and hurricanes
Although scientists are uncertain whether climate change causes tropical storms, they are certain that rising sea levels, warmer ocean temperatures, and the weakening of tropical circulation do intensify the effects of climate change.
Resource: Google images
Six months after the destructive Hurricane Michael passed through State of Florida, people are still trying to put their lives back together. The Category 4 storm that happened last October, killed 43 people and caused about $10 billion of damage.
Approximately 40,000 homes were damaged or completely destroyed, and many people continue to live in tents. Shelley Summers provides a tent city in the backyard of her house for 17 men, women and children who have no place to go.
"They lost their homes and they needed a sense of security and a sense of belonging. That was the biggest thing for me," Summers said.
Approximately 40,000 homes were damaged or completely destroyed, and many people continue to live in tents. Shelley Summers provides a tent city in the backyard of her house for 17 men, women and children who have no place to go.
"They lost their homes and they needed a sense of security and a sense of belonging. That was the biggest thing for me," Summers said.
Hurricanes similar to Michael happen several times a year in different parts of our planet. They cause extensive damage to nature, people's health, and the economy. While scientists point out a few reasons why tropical cyclones are increasing in intensity, whether hurricanes are a direct result of global warming is an open issue.
The reasons are:
The reasons are:
Sea level rise
Sea temperature rise
Weakening of circulation
Sea level rise
Sea level rise is linked to thermal expansion and melting glaciers, and is a consequence of human-caused global warming. According to scientific evidence, over the last century the sea level has risen by 17cm.
Many scientists agree that general sea level rise is intensifying the impact of tropical cyclones. A group of scientists from Texas A&M University declared that global warming has the potential to increase hurricane flooding through the rising sea levels.
While analyzing the storm surge from Hurricane Florence, the First Street Foundation has found out that "1-in-5 of the homes impacted along the Carolina coast wouldn't have fared so badly had sea levels not risen significantly since 1970."
Sea level rise is linked to thermal expansion and melting glaciers, and is a consequence of human-caused global warming. According to scientific evidence, over the last century the sea level has risen by 17cm.
Many scientists agree that general sea level rise is intensifying the impact of tropical cyclones. A group of scientists from Texas A&M University declared that global warming has the potential to increase hurricane flooding through the rising sea levels.
While analyzing the storm surge from Hurricane Florence, the First Street Foundation has found out that "1-in-5 of the homes impacted along the Carolina coast wouldn't have fared so badly had sea levels not risen significantly since 1970."
Hurricane Florence, weakens slightly, as it churns toward East Coast. Resource: SBS News
Rising sea surface temperatures
Hurricanes draw energy from the ocean surface at a depth of 2,000m. The warmer water is, the more power a hurricane has. Climatologists warn that the temperature of the ocean is getting hotter every year. Last year was the hottest on record.
Tropical cyclones need warm water to release heat in the upper atmosphere, creating spiraling winds. That is why the warm features of the upper ocean can significantly affect the intensity of hurricanes.
Mark Saunders and Adam Lea conducted an experiment which showed that "a 0.5°C increase in sea surface temperature is associated with a ∼40% increase in hurricane frequency and activity."
The graphic bellow illustrates the tracks of simulated Atlantic category 4 & 5 hurricanes for the current climate and a warmer climate in the late 21st century. This is just a prediction, but it offers a general idea of the effect rising temperatures may produce.
Hurricanes draw energy from the ocean surface at a depth of 2,000m. The warmer water is, the more power a hurricane has. Climatologists warn that the temperature of the ocean is getting hotter every year. Last year was the hottest on record.
Tropical cyclones need warm water to release heat in the upper atmosphere, creating spiraling winds. That is why the warm features of the upper ocean can significantly affect the intensity of hurricanes.
Mark Saunders and Adam Lea conducted an experiment which showed that "a 0.5°C increase in sea surface temperature is associated with a ∼40% increase in hurricane frequency and activity."
The graphic bellow illustrates the tracks of simulated Atlantic category 4 & 5 hurricanes for the current climate and a warmer climate in the late 21st century. This is just a prediction, but it offers a general idea of the effect rising temperatures may produce.
Resource: NOAA GFDL
A general weakening of tropical circulation
Global warming has dramatically reduced the speed of hurricanes in the Atlantic and Pacific oceans. James Kossin from NOAA has studied the hurricanes formed between 1949 and 2016 and concluded that their speed gradually decreased with time. The climatologist believes that this is a consequence of climate change.
According to Kossin's scientific paper, the speed of tropical cyclones since 1949 has decreased by 20% in the Atlantic ocean, by 30% in the northwestern part of the Pacific ocean and by 19% on the coast of Australia. As a result, a level of precipitation has doubled and flooding has become more extreme.
A decrease in the speed of a cyclone causes another dangerous phenomenon — because of very weak prevailing winds a hurricane might change direction and strike flooded regions for the second time.
Global warming has dramatically reduced the speed of hurricanes in the Atlantic and Pacific oceans. James Kossin from NOAA has studied the hurricanes formed between 1949 and 2016 and concluded that their speed gradually decreased with time. The climatologist believes that this is a consequence of climate change.
According to Kossin's scientific paper, the speed of tropical cyclones since 1949 has decreased by 20% in the Atlantic ocean, by 30% in the northwestern part of the Pacific ocean and by 19% on the coast of Australia. As a result, a level of precipitation has doubled and flooding has become more extreme.
A decrease in the speed of a cyclone causes another dangerous phenomenon — because of very weak prevailing winds a hurricane might change direction and strike flooded regions for the second time.
Hurricane with stormy background. Resource: cediss.info
Does global warming bear responsibility for hurricane formation and its increasing intensity?
Many scientists agree that hurricane activity has increased significantly since the middle of the last century, but the underlying causes of this increase remain uncertain.
There is no consensus on whether climate change has affected the statistics of tropical cyclones yet, due to the lack of the data sets. At present, the period of the consistent scientific observations of this natural phenomenon is limited to less than a hundred years. Therefore, scientific researches on that subject are based on computer simulations. For more reliable results, more observation data is needed.
Many scientists agree that hurricane activity has increased significantly since the middle of the last century, but the underlying causes of this increase remain uncertain.
There is no consensus on whether climate change has affected the statistics of tropical cyclones yet, due to the lack of the data sets. At present, the period of the consistent scientific observations of this natural phenomenon is limited to less than a hundred years. Therefore, scientific researches on that subject are based on computer simulations. For more reliable results, more observation data is needed.
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It is premature to conclude that human activities — and particularly greenhouse gas emissions that cause global warming — have already had a detectable impact on Atlantic hurricane or global tropical cyclone activity. Human activities may have already caused changes that are not yet detectable due to the small magnitude of the changes or observational limitations, or are not yet confidently modeled.
We may have to wait decades to learn precisely how global warming affects tropical cyclones. However, global warming does exist and it is definitely affecting our planet. Measures should be taken to freeze climate change before it's too late.
For more information please watch Kerry Emanuel (Massachusetts Institute of Technology) who explains the connection between climate change and the increasing intensity of hurricanes.
