I expected that moving to the East coast of India for college would be all about the beaches and the Rassagulas. However, 2 years into my stay in Odisha I experienced FANI. Being in the eye of the storm (literally) of something that used to be an ignoreable news story was genuinely scary and I have been obsessed ever since. And as Hurricane Beryl follows the Indian cricket team in taking the Caribbean by a storm, I wanted to take a look at tropical storm climatology. Stronger storms are occurring earlier in the season and getting intense faster, exposing generally vulnerable coastal communities to even greater risk of destruction. But first we actually have to gather this data. 

Researching storm classifications made me pretty pessimistic about finding homogenous data that would be easy to plot. But then WMO to the rescue, working with the various meteorological departments that monitor the different basins, WMO compiles International Best Track Archive for Climate Stewardship (IBTrACS), talk about a laboured acronym. This is a near real time dataset that compiles information about tropical and extra tropical storms all in a single file, information from each meterological agency is given alongside the WMO reported values for every storm in the list that goes back to 1842. The entire dataset is available on the NOAA NCEI website. So, let's ask some questions of it, first up, are we getting more cyclones?

There certainly appears to be a large increase in number of reported storms between 1960 to 1980, plateauing out in the more recent decades. Is this climate change?

flashback to April 1960... . The space race is rapidly approaching, new avenues of Earth observation are about to open. The value of satellite weather observations continues to be unproven because of the repeated failures of the Vanguard 2 satellite. It's successor, The Television Infrared Observation Satellite Program (TIROS) was the first weather satellite to successfully reach orbit and begin observations. An explicit goal of the TIROS satellite was  to improve decisions that are otherwise hard to make from Earth-bound observations like "should we evacuate the coast because of a hurricane?". and with TIROS beginning continuous coverage of the Earth's weather in 1962 we began to identify more storms that might have otherwise gone unnoticed or would have lacked enough observations to be included in the archive. Since, 1960 we have continued to add more weather satellites into orbit around the planet and today we have a near continuous and universal coverage of the entire surface of the planet in multiple spectral bands. And that is the steep increase in storm counts from 1960 to 1980.

The dominant effect of internal climate variability on storm formation also makes it harder to observe any changes that may be caused due to climate change. While it is a welcome realisation that the number of tropical storms is not increasingly drastically with climate change it does not mean that the process is immune to the effects of a warming planets. One effect is that the storms that do take shape have more food to available and so they grow stronger and more violent.

The most dramatic of weather events that cause the most visceral damage to humans does not appear to be undergoing a dramatic worsening because of climate change.  But the damage they cause is worsening, storm surges get higher every year as sea level rises, exposing new regions to storm flooding. The increasing amounts of latent energy that is being taken up by storms leads to changes in their dynamics, causing greater amounts of rainfall. All these effects have been shown to be caused by anthropogenic climate change and will continue to become more extreme as temperatures rise.