By Brittany Hoedemaker
Wildfire ash raining down from the sky. Bats falling out of trees. Hair-freezing temperatures. No, these aren’t just scenes from my nightmares. They’re real events being seen around the globe, with climate change projected to unleash even more frequent and more intense extreme weather events. But what’s the difference between weather and climate change, anyway?
Here’s the deal: weather is the atmospheric conditions at a moment in time, while climate is the atmospheric conditions averaged over a long period of time (usually over 30 years). For example, the weather today in Seattle is cold and snowy, in Houston it’s warm and rainy, and in San Diego it’s mild and sunny. However, these weather conditions will be slightly different tomorrow, and will be unique to each geographic location. After averaging these weather conditions out over a long period of time, we can categorize Seattle’s climate as temperate, Houston’s as humid subtropical, and San Diego’s as Mediterranean.
Still confusing? Put it this way: most people think “Seattle” is synonymous with “rainy.” So, on a 90 degree day in August, would you try to argue that Seattle has a tropical climate? No! Of course not! Because you know that on average Seattle is temperate, and those few hot days don’t discount the rest of the year’s weather. Nor does our latest snowstorm warrant a climate reclassification for the region as “tundra.”
Now you’re up to speed now on the difference between weather and climate, but you may wonder: does distinguishing between them really matter? The answer is a resounding “yes!” When bitter winter storms bring snow and cold weather to the U.S., out comes a cacophony of climate change skeptics mocking the existence of “global warming.” Herein lies the importance of understanding that cold weather events will not cease to exist despite a warming Earth. Similar to weather, climatic conditions vary (just over longer timescales), and that variation is not uniform across the globe, or even across the United States.
In fact, the Fourth National Climate Assessment notes in the climate chapter that some studies show increased frequency of the most intense northeastern winter storms, and recent snowfall and storm events in the Midwest and Northeast are consistent with climate change model projections. Thus, it’s critical to remember that periodic weather events do not refute long-term climate change projections. Furthermore, while some areas may experience intense winter storms, other changes in long-term weather patterns may result in longer periods of drought and higher temperatures leading to increased wildfire intensity. These changes aren’t far off into the future, either. The International Panel on Climate Change (IPCC) notes extreme weather events as one of the five Reasons for Concern (Figure SPM.2) about global warming, with impacts directly attributable to climate change already being seen around the globe.
What’s the difference between global warming and climate change, then? Global warming is typically used in reference to the average temperature of the globe increasing since the industrial revolution. Climate change refers more broadly to how various climate parameters (rainfall, snowfall, sea level, wind and storm patterns, biogeographical shifts) respond to global warming.
While the terms are used almost interchangeably within the field of climate science, science communicators including Columbia University’s Center for Research on Environmental Decisions argues in its “The Psychology of Climate Change Communication” guide that “[c]limate change is a better choice than the term global warming because it avoids the misleading implications that every region of the world is warming uniformly” (cue the aforementioned Twitter cacophony!). Furthermore, studies have found that for the American public “global warming and climate change are often not synonymous—they mean different things to different people—and activate different sets of beliefs, feelings, and behaviors, as well as different degrees of urgency about the need to respond.” This last part especially matters because if using “global warming” instead of “climate change” (or vice versa) could invoke different responses in individuals, it means terminology usage has the potential to influence support or disapproval of climate-related policy.
As we continue to alter our planet through the burning of fossil fuels, it is important to clarify these definitions as we communicate the short and long-term implications of our actions to the American public. Terminology choice can be misleading and can undermine the potential for consensus and progress on climate change policy. Precise use of “weather” and “climate,” as well as thoughtful use of “climate change” and “global warming” are essential to promoting an accurate understanding of the dynamic nature of climate change and the risks we face in the future.