We’ve all heard about climate change and its effects being induced by human activities, but how would we show this correlation? We can start with a one very observable phenomenon: Hurricanes. Have the frequency and intensity of these extreme weather events changed in the past century? If so, how can we relate them to climate change and ultimately the impacts that human activity has had? These are the topics i’ll address.
First we look at the frequency of hurricanes in the past century and a half or so.
Next, we can see that the average PDI of storms has also increased in the past few decades. It is most observable to the population of North America specifically in the number of category 4 and 5 storms that have hit.
PDI: Power Dissipation Index, a measure of hurricane intensity
So according to these graphs, hurricanes have increased in frequency and intensity over the last century. However, the second graph points out the correlation between sea surface temperatures and hurricane PDI’s. How is this related? Let’s take a look at a graph of average global sea surface temperatures and how they’ve increased.
We see that in the past century, global sea surface temperatures have increased from around -1 degree F to roughly 0.5 degrees F. This increase correlates to the increased PDI seen in the last graph.
Lastly, we add the human factor. What changes have humans caused that results in climate change and eventually, an increased number of hurricanes? All modern research points to one main culprit: CO2. After the industrial revolution, levels of CO2 continued to increase at an exponential rate. To summarize the cause quickly, this and other greenhouse gases add to the greenhouse effect, heating up the surface land and water.
Here we can see the correlation of emissions and average global temperatures.
For further evidence of increased hurricane intensity, we look to the most recent and most severe hurricane to date: Patricia. If the storm would have hit at full capacity, winds of over 200 mph would have resulted in a huge storm surge, which could have caused damage and loss of life on an unprecedented scale.
It’s a simple yet devastating correlation:
Increased emissions → Increased SST → Increased # of stronger Hurricanes
If we don’t curb emissions and change policies soon, we will set ourselves up on a course for disaster that we can’t turn away from.