A recent article in The Conversation suggests, based on new evidence of past hurricane frequencies, that coastal areas and islands in the Atlantic Hurricane basin could be facing a dire future involving greater threat from hurricanes. This seems an odd claim since the evidence the article provides indicates that during the recent period of warming hurricanes are less frequent than they have been in the past, with the most intense periods of hurricane activity occurring when seas were cooler. Indeed, the data shows hurricanes were more frequent during multiple periods over the past approximately 2,000 years, than they are at present, all when carbon dioxide levels were much lower than today. This fact suggests there is no causal connection between carbon dioxide concentrations and hurricane formation.
In The Conversation story, “We’re decoding ancient hurricanes’ traces on the sea floor – and evidence from millennia of Atlantic storms is not good news for the coast,” the author, Tyler Winkler, correctly notes:
[The 2022 hurricane season provides] a reminder that small sample sizes can be misleading when assessing trends in hurricane behavior. There is so much natural variability in hurricane behavior year to year and even decade to decade that we need to look much further back in time for the real trends to come clear.
Fortunately, hurricanes leave behind telltale evidence that goes back millennia.
Two thousand years of this evidence indicates that the Atlantic has experienced even stormier periods in the past than we’ve seen in recent years.
The evidence Winkler is discussing is borehole cores containing sediment and shell deposits found in coastal marshes, sink holes, and ponds from various locations on the Atlantic coast and various islands.
What the Winkler’s data shows is that over the past 2,000 years, decadal data show hurricanes, including strong hurricanes, often occurred more frequently in the past than in the present, during periods of both higher and lower temperatures.
“For example, Thatchpoint Blue Hole on Great Abaco Island in the northern Bahamas includes evidence of at least 13 hurricanes per century that were Category 2 or above between the years 1500 and 1670,’ reported Winkler. “That significantly exceeds the rate of nine per century documented since 1850.”
Winkler’s data clearly demonstrates that there have been multiple periods in the past, when carbon dioxide concentrations were much lower than at present, when hurricane frequency and severity was greater. This conclusion is confirmed in every core sample from every location. (see the graphic below)
In every sample, the evidence suggest that time the period which produced the greatest number of hurricanes were multiple decades in the middle and towards the end of the little ice age. Despite his own research indicating natural factors, not anthropogenic climate change, have driven hurricane cycles throughout history Winkler writes, that the evidence “tells coastal oceanographers like me that we may be significantly underestimating the threat hurricanes pose to Caribbean islands and the North American coast in the future.”
It is unclear what Winkler’s stated fear is based on. Indeed, alternative sources of data and other research confirms that factors, some of which Winkler discusses, like wind shear and multi-decadal oceanic oscillations in ocean currents, not warmer temperatures are responsible for the rise and fall in hurricane incidences.
For example, Climate Realism has published dozens of posts, like here, here, and here, exploring the factors that drive hurricanes and demonstrating there is no evidence they have become or are likely to become more frequent or severe in the near future, based on our current understanding of hurricane dynamics. Also, the Intergovernmental Panel on Climate Change’s most recent report finds no evidence the modest warming that the Earth has experienced since the end of the little ice age around 1850 has impacted hurricane patterns or that there is any “human fingerprint” on hurricane numbers or intensity.
Rather than warning of a grave future due to climate changes’ model projected impacts on future hurricane cycles, Winkler should trust what his own data and research show. It provides no evidence that human energy use is having any effect on the formation of hurricanes or their relative power when they form.
Winkler is right to warn that hurricanes pose a danger to coastal areas in the Atlantic basin, but this is something everyone already knows. It is equally clear, that modern settlement patterns and population growth near coastal areas prone to hurricanes have contributed to greater numbers of people and associated infrastructure being impacted when hurricanes strike. It is good to be prepared and take steps to minimize the devastating impact hurricanes often have on society.
Efforts to control climate change by limiting the use of life sustaining fossil fuels will do nothing to either prevent hurricanes from forming or to reduce the harm when they occur. Rather policies restricting fossil fuel use will make minimizing the negative impacts of hurricanes harder.