Explainer: What is attribution science?
Climate and weather are related — but not the same. Climate describes patterns of weather in an area over long stretches of time. Weather refers to specific events, such as hot days or thunderstorms. Heat waves, droughts, wildfires, hurricanes, tornadoes and floods are all examples of extreme weather.
When extreme weather occurs, people often want to know if climate change is to blame. However, notes Stephanie Herring, “there’s no way to answer that question.” Herring is a climate scientist at the National Centers for Environmental Information in Boulder, Colo. Any weather event could happen by chance, she explains. It could simply be part of the natural variation in weather.
It’s better, she says, to ask about the influence of climate change. A region’s climate sets the stage for an extreme event. Scientists can then probe: Did climate change make some extreme event worse?
Investigating links between climate and extreme weather is known as attribution (Aa-trih-BU-shun) science. Such studies often can be tricky — but not impossible. And in recent years, scientists have developed ways to do it with ever more confidence.
An important part of that process is asking the right questions, explains Herring. Then scientists use computer models to analyze climate data with math. Those scientists are finding new and better ways to quantify, or measure, the impacts of climate change. Think of them like sports scientists who might study a player who hit 10 home runs in a single game. Did that athlete have a really good night? Or did he cheat in some way? And how can you know for sure? With enough data and some pretty fancy math, trustworthy answers to such questions may emerge.
Scientists had long predicted climate change would worsen some extreme weather events. It might also make them more frequent. With attribution studies, signs have recently begun to offer support for that. They can show not only that a link is real, but also how strong it is.
attribution science A field of research, largely used in climate studies. It seeks to test whether — and by how much — climate change may be responsible for certain extreme weather events, such as droughts, extreme flooding, hurricanes, excessive heat or odd storm trajectories.
climate The weather conditions that typically exist in one area, in general, or over a long period.
climate change Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.
computer model A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.
data Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.
drought An extended period of abnormally low rainfall; a shortage of water resulting from this.
model A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes. Or an individual that is meant to display how something would work in or look on others.
weather Conditions in the atmosphere at a localized place and a particular time. It is usually described in terms of particular features, such as air pressure, humidity, moisture, any precipitation (rain, snow or ice), temperature and wind speed. Weather constitutes the actual conditions that occur at any time and place. It’s different from climate, which is a description of the conditions that tend to occur in some general region during a particular month or season.