Climate Change Vs. Weather: The Difference Is Time

By Dr. Mark LeChevallier – January 9, 2013 – Comment

After any large-scale weather phenomenon, we are left with the cleanup and the lingering question: How can we prevent this from happening again? The aftermath of Super storm Sandy is, of course, no exception. We’re hyper-aware of the many changes that are happening to the earth at this time in history, and policy makers and scientists alike wrestle with climate variability and how best to cope with it. Perusing articles about Sandy leads the reader to a flurry of speculation…is it “climate change”, or is it just freak weather?

Well, let’s examine that. There is, in fact, a difference between climate variability and weather, and according to NASA, that difference is time. Weather is short-term, and climate “change” is a long-term, typically 30 year, span. The best thing we can do is twofold; 1. We can adapt and plan for the effects of long-term climate variability, and 2. We can work to mitigate current contributing factors where possible. For example, there are areas of Lower Manhattan that were not equipped to handle the onslaught of water that Sandy brought. Building barriers or levees that could have held off some of the water would be one step towards better future preparedness and planning as a solution that makes sense. Fortunately, water service through the storm remained intact even as other services and accessibility faltered, but the scenario could have easily been different.

As it relates to Sandy, this article from Scientific American does a great job of explaining some background. Basically, Sandy travelled north along the East Coast, picking up water that was still warm and using it as an energy surge. The storm expanded when the Jet Stream dipped south and forced cold air into the storm, which mixed with the warm Atlantic to provide even more energy for the super storm. All of these things happened during a small, isolated period of time.

Here’s where climate variability comes in: There is a phenomenon called NAO (North Atlantic Oscillation), which is the state of atmospheric pressure in the North Atlantic, and it can be positive or negative. Just before Sandy, it went negative, resulting in a wavy jet stream that quickly dipped south. Researchers at Cornell believe that as polar ice caps melt in the Arctic, the NAO is more likely to be negative during fall and winter. 

Sandy gave us a hard reminder of the immense power of water. There are many uncertainties associated with changing climate patterns and its impact on water, but there is little doubt that climate variability could disrupt water quality and supply without adequate planning and risk assessment. The bottom line is that communities, no matter how large or small, need to come together to better plan around both climate variability and weather. For now, we rebuild, replant, and move toward better preparing for future weather events.