Badwater Basin in Death Valley, California. Over the past few days, temperatures in Death Valley have soared to 130 degrees Fahrenheit, matching or possibly exceeding the highest temperatures on Earth in 90 years. Image courtesy of Pixabay

Editor’s Note: This story was originally posted by Yale Climate Connections.

For some Americans, the signs of global warming are everywhere. In 2020 alone, wildfires broke records across the West, hurricanes fueled by unusually warm ocean temperatures hit the southeast, and a Death Valley weather station recorded a temperature. of 130 degrees Fahrenheit, perhaps the hottest daily maximum to be reliably documented on Earth. Now, drought has taken hold across much of the West, causing what is expected to be an extremely active fire season.

Climatologists have warned for decades that global warming will lead to more extreme weather conditions. And as more Americans begin to experience disastrous weather events personally, it is reasonable to question whether they will support aggressive climate action.

The short answer is already clear: not necessarily.

The signal of climate change is difficult for people to perceive against the noisy backdrop of daily and seasonal weather changes.

But even when a neighborhood, city, or region is experiencing truly unusual weather, some will see it as clearly linked to global warming, while for others the connection may not even occur to them. Just as two people can react in completely different ways to political events, the current fashion, or a football game, two people can share what appears to be the same experience and yet draw completely different conclusions about what is going on. happened, what caused it and what to do about it.

“The experience” is much more slippery than most of us realize. We don’t just use our senses to record information about our surroundings and everyday events – we to interpret these events and filter them through our emotions, our memories, our culture and, in the case of weather and climate, our politics. We then combine our beliefs, attitudes and evaluations of our past experiences to form new opinions, build new cause-and-effect models in our minds, and ultimately build accounts of events that allow us to make sense of the world and how we fit into it.

The Yale Climate Change Communications Program, publisher of Yale Climate Connections, has used nationally representative surveys for 12 years to determine which Americans believe they have personally experienced global warming.

The data shows that Democrats and Republicans living in the same states or counties – or even sharing the same roof – can be a world apart when it comes to the perceived experience of global warming (Figure 1). While 60% of Democrats say they have personally experienced global warming, only 22% of Republicans agree.

Democrats vs GOP on Climate Change Evidence
Figure 1. Percentage of Republicans and Democrats who say they have personally experienced the effects of global warming, by state, 2008-2018. Data from Mildenberger et al. 2017. For Democrats, estimates range from 53% in Wyoming to 66% in Oregon. For Republicans, estimates range from 14% in West Virginia and Wyoming to 48% in Hawaii and New York. (Source: Marlon et al. 2021)

Hot, dry days influence perceptions. The strong influence of partisanship on people’s understanding of global warming may not be surprising, but are there any climate changes that people are more likely to associate with “global warming?” If there are, these weather events are potential topics for climate change conversation.

In a recent study published in the journal Global environmental change, my colleagues and I tried to answer this question by combining 12 years of survey data from the Yale Climate Change Communication Program with 11 different temperature and precipitation indicators of changing weather conditions over time. time. Together, the indicators captured long-term trends in temperature and precipitation, as well as recent episodes of extreme heat, precipitation, and snowfall between 2008 and 2015.

We found that only one type of weather affected Americans’ belief that they had experienced global warming: hot, dry days. When hot, dry days persist for a long time, drought conditions arise. In particular, the intense heat and lack of precipitation that hit Texas in the Midwest in 2011, which turned into a severe drought, is evident in the study’s climate data (Figure 2, top panel). That drought was also associated with extreme wildfires in Texas, which burned about 4 million acres that year, doubling the previous record.

Figure 2. Geographic signature of the hot and dry day anomaly, September 2012 to March 2015. Top row: Hot and dry day anomalies by year. Bottom row: Differences between the perceived experience of climate change at the county level for the years 2009-2014 using the Yale Climate Opinion Maps model (Howe et al. 2015) and the estimates of the perceived experience at the using a model with the addition of hot and dry day anomalies. (Source: Marlon et al. 2021)

To see the influence of climate on people’s experience, we had to model it. The red and gray maps show the difference between a model that includes the influence of hot, dry days on people’s experience of global warming and one that does not (Figure 2, bottom panel). Red areas indicate where more people have personally reported experiencing global warming each year. The figures show that it was not only the drought in Texas of 2011 that influenced people, but also the droughts in the West in 2008, 2010 and 2014, and in the Midwest in 2012 and 2013. In contrast, the Darker gray areas of the Midwest in 2008 and 2010, for example, and along the East Coast in 2012, show that people there were less likely in those years to say they had experienced global warming.

The effects of actual weather and climate change on people’s experience of global warming are still subtle compared to the influence of politics. But as heat, drought and other severe weather events continue to become more extreme, many of us are hopeful that more people will be persuaded to reduce our carbon emissions more aggressively.

People don’t make the connection between showers and global warming. Encouragingly, some people are associating local increases in heat, drought and drought with the larger problem of global warming. Extreme heat is the leading cause of weather-related deaths in the United States, and its increasing frequency leads to greater heat-related risks, such as dehydration, heatstroke, and exhaustion. Moreover, these effects disproportionately hit the most vulnerable among us.

Today we are breaking records for heat twice as fast as records for cold, which before the 1950s were about as likely to occur. Drought is the most persistent extreme weather event and has devastating effects on agriculture and water supply, which may explain why people were likely to remember it and associate it with climate change.

In our study, people did not link local increases in heavy precipitation to global warming. Given that the links between global warming and precipitation patterns are more complex than those linked to temperature alone, this is perhaps not surprising. Yet the relationship is important and has major consequences for our economy and our health. Scientists recently calculated that the impact of global warming on Hurricane Sandy includes an $ 8 billion price tag from flood damage. But many Americans don’t understand how carbon pollution could lead to increased flooding and hurricane damage. For them, the dots have not yet been connected between cause and effects.

Many strive to connect these dots, showing how climate change is already shaping our lives and explaining the causal chains between the burning of fossil fuels, global warming and increasing extreme weather conditions. Kenton Gewecke, chief meteorologist at KOMU 8 in Columbia, Missouri, is just one example. He hosts a series called “Show Me Climate,” in which he talks to scientists and explains how temperatures, precipitation, storms and other events are changing in Missouri. Gewecke says many viewers appreciate the information. If other broadcast meteorologists follow Gewecke’s lead, they will serve as trusted and knowledgeable guides to help Americans understand and learn from our experiences.



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