Charts in the wild! Visualizing Florida’s population growth

The U.S. Census Bureau reports that in 2022, Florida was the fastest-growing state in the country for the first time since 1957. Each decade since World War II, my home state’s population growth has been positive. It increased by 1.9% to 22,244,823 between 2021 and 2022, according to the Census.

The average annual growth rate of all states was 0.5% in 2020. In Florida, it was 2%.

At Tableau Conference last week, the three Iron Viz finalists were assigned a renewable energy dataset to visualize. As she presented her analysis and visualization, fellow Floridian Brittany Rosenau emphasized the need to consider sustainable growth in our state. I’m grateful to the Tableau and Salesforce team for choosing an impactful dataset for this highly anticipated contest. We humans sometimes struggle to understand the gravity of the environmental impacts of our actions. Data visualization can facilitate understanding of complex scientific data and large numbers that are difficult to grasp. When we do it well, it can make the abstract more concrete, inspiring us to take action.

I’ve encountered three charts “in the wild” addressing — with varying degrees of success — the topic of population growth in Florida over the past couple of weeks.

This hybrid quadrant chart/bubble chart from Chartr provides context for understanding Florida’s growth by showing the net migration of individuals and percentage change in population of both growing states and states Americans are leaving. There’s a lot happening in this chart, but each element serves a purpose. On the x-axis is the raw number of people (the size of the population) that have migrated to or from a state. On the y-axis is the percentage change in population.

The bubble size represents the same measure as the position along the x-axis: the number of people moving. This is an example of double encoding (also called redundant encoding), or the presentation of the same information more than once in a visual. It is considered a poor practice by some data visualization practitioners (even “experts”), but research from Northwestern University and M.A. Borkin et al. (summarized nicely for the Tableau blog by Mike Cisneros and Lilach Manheim) has shown it can improve readability and the viewer’s understanding of the chart. Imagine for a moment if the bubbles on this chart were all the same size. Even with the annotations (text like “S. Carolina +84k”), it would take us longer to discern the key takeaway of this chart. Chartr also employed color encoding to show which states lost population (red) and which gained (blue). This additional encoding allows us to see nearly instantly which states gained and lost population, much like the bubble sizes allow us to see the degree of population change.

For years, people from all over the U.S. and the world have migrated to Florida for its beautiful weather and abundance of natural — and weird, unnatural — wonders from Crystal River State Park to South Beach to the mermaids of Weeki Wachi Springs to Walt Disney World. They also come for the business-friendly climate, the nonexistent state income tax, and lax environmental regulations. In 2010, Republican governor Rick Scott encouraged years of unfettered land development when he disbanded Florida’s Department of Community Affairs, the state agency tasked with managing growth. NPR reported that the disbanding of the agency may have also increased the impact of last year’s Hurricane Ian, which killed at least 149 people in 19 counties.

All of this migration is taking an environmental toll on Florida. Sea levels are rising, wildlife habitats are dwindling, and important wetlands and watershed areas have been destroyed or are at risk. In March, the University of Florida and 1000 Friends of Florida, a land-use advocacy organization, released a joint report cautioning against continued reckless development. They urged the state to prioritize protection of the most vulnerable lands.

I’ll acknowledge my bias right up front — I’m a superfan of Axios Visuals’ clean and aesthetically pleasing visualizations. Their minimal aesthetic doesn’t introduce unnecessary complexity and employs color palettes that are interesting but don’t distract from important topics such as this one. It’s easy to spot an Axios graphic. They’re consistent about the typeface, placement of legends, and labeling. And they sometimes have fun with charts, too. (Information designer Chesca Kirkland wrote an enjoyable piece about their process, Behind the Scenes with Axios Data Visualization, in July for Nightingale.)

As indicated by the dark green and light gray-shaded areas, this viz focuses on where the fast growth happened (dark green) and did not happen (light gray) between 2020 and 2022.

Central Florida

Central Florida grew at 5% per year or more, except in Hillsborough, Pinellas, Orange, and Seminole counties, areas which experienced moderate growth (between 1% and 5%). The cities of Tampa, St. Petersburg, and Orlando are situated in these moderate-growth counties and generally have a higher cost of living than faster-growing Pasco, Hernando, Citrus, Lake, Marion, Sumter, Polk, and Osceola. The Villages, a census-designated place (CDP) rather than a city per se, was the fastest growing metro area in the U.S. in 2020. (It’s located in parts of Sumter, Marion, and Lake counties.)

Pinellas County, home of just under 1 million residents, the hip city of St. Petersburg, and some of the country’s most beautiful beaches, has maintained its population, but lacks the slight growth indicated by the light green of Hillsborough, Orange, and Seminole.

The Panhandle

In the Panhandle, the Emerald Coast counties — Gulf, Bay, and Walton — experienced significant growth. Leon County, home to the state capitol of Tallahassee, experienced moderate growth. (DeSantis is probabIy trying to get it banned, but before he does, I highly recommend you watch the 2021 Suncoast Regional Emmy Award-winning documentary Invisible History: Middle Florida’s Hidden Roots, directed by Valerie Scoon of Florida State University’s College of Motion Picture Arts. The film uncovers the little-known plantation culture of the county and how its large enslaved population shaped the county and region. It’s on Amazon Prime, Apple TV+, and PBS.)

North and South Florida

In these boom years, a few counties actually declined in population. In South Florida, remote Monroe County, home to the Florida Keys, is losing population along with North Florida’s Taylor, Baker, Bradford, Hamilton, Liberty, and Calhoun counties. My educated guess about the causes of Monroe’s population loss include its combination of vulnerability to increasingly dangerous hurricanes and pricier home insurance (guess why), geographical remoteness, and the cost of real estate.

Also in South Florida, Miami-Dade — the most populous Florida county with about 2.67 million residents — added no significant new growth from 2020 to 2022 according to the Axios map.

To compare several segments of populations, a pictogram — basically a unit chart made with icons — is generally a good chart choice. The Florida Chamber of Commerce created one to show possible future population growth versus the population at the time of publication in ten counties where they predict half of the total new growth by 2030 will occur. While the map didn’t show recent growth, the Chamber’s pictogram shows that the county’s population could increase to 3 million by 2030.

The chart clearly shows the projected growth in the selected counties, but it really falls short from an accessibility perspective. The lighter blue (#52B3D9) text and icons on the darker blue (#254290) background does not meet Web Content Accessibility Guidelines for normal-sized (16 px) text — the bare minimum color contrast guidelines. The green (#8BC646) meets the WCAG guidelines, but would need to be 32 px or larger to meet a more truly accessible standard like APCA (the Advanced Perception of Color Algorithm). Also, I’m confused about why the legend has a white background and the rest of the chart does not.

The environmental impact of population growth is just one area where well-executed data visualizations can raise awareness about an urgent issue, inform the public, and inspire action.

Have you seen any impactful charts related to the environment, population growth, or climate change lately? Send them my way! And I’m interested in what you think about the effectiveness of these three charts. Let me know in the comments or DM me on Twitter.