“It’s physics, actually”

Warmer oceans and warmer air equal bigger storms

A few years ago, my wife and I hosted an exchange student from Colombia.  She had a healthy curiosity, so many suppertime conversations were centered around science and the way the world works.  In answering her questions, I often found myself starting with, “It’s physics, actually.” 

That’s because physics, the study of matter, motion and energy, is at the heart of the way our world works.  And that sure hit home this past week when Hurricane Helene pounded much of southeastern US. 

Here are a few key facts about physics and climate that I hope will resonate:

• It’s a simple principle of physics that warm water evaporates more easily than cold water.  So when oceans warm, more water evaporates from them.
• It’s another simple principle of physics that warm air holds more moisture than cool air.  In fact, for every one-degree C of warming our atmosphere can hold about seven per cent more moisture. 
• About 90 per cent of global warming so far has taken place in our oceans, which are warmer than ever.  Just 10 per cent has happened on land, where we humans live.
• Globally, 2023 was the hottest year on record, with an average temperature about 1.35 degrees C higher than pre-industrial revolution temperatures.  So far 2024 is even warmer.

Together, the above four points are a big part of the reason why last week’s Hurricane Helene was so severe: picking up an incredible amount of moisture over the Gulf of Mexico, and then dumping up to 75 cm of rain in localized areas (that’s three-quarters of a meter!!).  It’s no small irony that one of the communities hardest hit by flooding, Asheville, NC, was on a list of US cities expected to see an influx of people avoiding the impacts of climate change.

One final principle of physics to share: warmer temperatures also cause evaporation to happen more quickly from soil, causing more drought – which leads to crop failures and wildfires.  Yuck.

Two key takeaways here:

First, even in this era of lamentable scientific illiteracy, science really matters, because it’s the way the world around us works.  The more people understand about science, the better positioned we are to act.

Second, climate change is driven primarily by emissions from our burning of fossil fuels oil, coal and natural gas.  The sooner we can eliminate them, the sooner we’ll rein in our climate crisis… something for us all to think about every time we turn a vehicle key or flip a light switch.