No, hurricanes are not becoming more frequent and more severe

As I write this I am sitting watching coverage of Hurricane Irma as it bears down on Florida, specifically the Tampa area.

I first visited that area in 1978, I last visited two years ago. My parents winter in Largo, a city that sits on the peninsula between the Gulf of Mexico and Tampa Bay. Not only is their home in the path of this storm, but so are many of their friends.

I hope and pray that as Irma drops in intensity, currently it is a category 2 hurricane, that there will be less damage to people’s homes and businesses, less loss of life.

With so much life at stake, so many people worried about their homes, I find it distasteful to talk about storms like this in political terms and yet, I can’t escape it. Go on social media, read the mainstream media and you will be hit with claims and stories that Hurricane Irma, or Harvey, or Jose are all the result of climate change.

I’ve heard politicians make these claims over the past few days. It is cold, it is callous and it is false.

While I hesitate to enter the debate, I feel I must, just to put some facts on the table.

It doesn’t matter what your view of climate change is, the main question when someone says that these storms are more frequent and more intense due to climate change is to ask if that claim is true.

The simple answer is no.

You can review the chart I created below and follow the links yourself to see what we have seen in terms of hurricane activity since 2000. The most active year was 2005, the year of Hurricane Katrina.

But even in 2005, Katrina was not the most powerful storm, that would be Wilma which arrived in October 2005, two months after the weaker but more devastating Katrina hit New Orleans.

Between 2005 and now, no storm had reached the intensity of Wilma – that is until Hurricane Irma.

In between then and now we have seen some seasons have as few as 2 hurricanes and no major hurricanes, meaning category 3 or greater.

Look beyond the 2000s into history that dates back to the 1880s and you will see that there is a complete lack of a pattern.

You can look at the list of most intense hurricanes by pressure and you will see that after Wilma in 2005 the list jumps back to Gilbert in 1988 and then Labour Day in 1935 before going all over the map.

You can look at the severity index for hurricanes that make landfall in the United States and you will find that the most severe happened a long time ago – in 1961, 1989 and 1965.

Even looking at how long storms last won’t fit the pattern that those trying to use storms for a political agenda would have you believe.

The longest sustained storm at category 5 was in 1899 followed by 1971.

None of this helps those who are dealing with the storm or its aftermath right now but neither does it help to jump on storms like this and claim that this is proof of climate change or that it is proof of storms becoming more frequent, more severe or intense.

The facts don’t back those claims up.

UPDATE: Nick sends in this link from the National Oceanic and Atmospheric Administration, a paper published less than two weeks ago on the impact of climate change on hurricanes. It says the evidence is less than conclusive.

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. That said, 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 (e.g., aerosol effects on regional climate).

ANOTHER UPDATE: For those that still don’t want to believe me that a direct link between hurricanes and climate change cannot be established, please look at this Summary for Policymakers prepared by the United Nations Intergovernmental Panel on Climate Change which says there is “low confidence” of human activity increasing tropical cyclone activity (see page 5). This is the summary from the scientists for the politicians by the global body in charge of climate change at the UN.

Year	Number of hurricanes	Number of major hurricanes (Cat 3 +)	Strongest storm and maximum winds
2000	8	3	Keith 140 mph (220 km/h
2001	9	4	Michelle 140 mph (220 km/h)
2002	4	2	Isidore 125 mph (205 km/h)
2003	7	3	Isabel 165 mph (270 km/h)
2004	9	6	Ivan 165 mph (270 km/h)
2005	15	7	Wilma 185 mph (295 km/h)
2006	5	2	Gordon and Helene 120 mph (195 km/h)
2007	6	2	Dean 175 mph (280 km/h)
2008	8	5	Ike 145 mph (230 km/h)
2009	3	2	Bill  130 mph (215 km/h)
2010	12	5	Igor 155 mph (250 km/h)
2011	7	4	Ophelia 140 mph (220 km/h)
2012	10	2	Sandy 115 mph (185 km/h)
2013	2	0	Humberto 90 mph (150 km/h)
2014	6	2	Gonzalo 145 mph (230 km/h)
2015	4	2	Joaquin 155 mph (250 km/h)
2016	7	4	Matthew 165 mph (270 km/h)
2017* so far	6	3	Irma 185 mph (295 km/h)