Strategic use of visualizations and graphics, particularly when they are designed to be interactive, can be key to presenting large amounts of climate information in an easily digestible form. With outstanding graphics, audiences can engage directly with the information being presented, helping them make sense of large data sets and helping them see connections in complex phenomena.
Here’s an initial listing of some particularly effective climate graphics. If you don’t see your favorites below, please add a comment at the end of this feature identifying them.
This graphic is one of the best known and also the most hotly debated climate visualizations. Climate scientist Jerry Mahlman, a former director of NOAA’s Geophysical Fluid Dynamics Laboratory, dubbed the chart the “hockey stick,” because of the trend line’s sharply curving blade.
The hockey-stick graphic shows temperatures in the northern hemisphere during the past 1,000 years. Scientists used data from corals, tree rings, ice cores, and other records to estimate temperatures in the time before the use of thermometers became widespread. The chart also shows, in red, data from thermometers.
The graphic shows that recent temperatures are likely the warmest in the past millennium. The red color symbolizes data from thermometers, but to many readers, red also means “heat” and “danger.”
The chart is based on a paper published in 1999 in the peer-reviewed journal Geophysical Research Letters by climate scientists Michael Mann, Raymond Bradley, and Malcolm Hughes. It gained widespread attention in 2001 when IPCC scientists prominently included it in the Third Assessment Report. The chart has often been published — by climate advocates and deniers alike — without the gray error bars that represent uncertainty. Meanwhile, climate deniers attempted to discredit it, as described in this article in The Chronicle of Higher Education (subscription required). Eventually, the chart became the subject of 2006 congressional hearings and a review by the National Academy of Sciences and others. Subsequent research has upheld this basic conclusion: Temperatures in the late 20th century likely were significantly warmer than any other time in the past 600-1,000 years. Most scientists accepting the evidence of a human influence on recent decades of atmospheric warming accept the “hockey stick” research, and it has withstood numerous challenges and reviews. But among climate contrarians, there remains no more frequent target of their attacks.
Where do greenhouse gases come from, anyway? This chart by the World Resources Institute breaks down the origins of carbon dioxide, methane, and other gases by sector and end use. Although the graphic’s color-coding can be a bit confusing, it clearly shows the major contributors to climate change: energy production, agriculture, and deforestation.
Unusually hot temperatures broke records across the United States during July 2011. The National Climatic Data Center plotted the nearly 9,000 heat records tied or broken during the month, resulting in an image of nearly all of the United States. Significantly, more than 6,000 of the points were record high night-time temperatures. As night-time heat rises, people have a harder time recovering from daytime heat, which increases health risks (see here).
In the recent past, most Americans suffered through fewer than 10 days each year with temperatures above 100 degrees. But as Earth’s average temperature increases, 100-degree days will become more common. The U.S. Global Change Research Program created this simple interactive map that shows the number of days above 100 degrees in the recent past (1961-1979), and the number of 100-degree days that could occur in the future.
In addition to rising temperatures, a changing climate will likely increase American’s risk of air pollution, drought, flood, and disease. The Natural Resources Defense Council, an environmental advocacy group, produced this interactive graphic about climate threats in your region. Enter your Zip code to find out how climate change could affect your area and how your state is responding.
What are the best (and worst) foods for the climate? This graphic from the Environmental Working Group, a nonprofit research and advocacy organization, suggests that tomatoes and lentils are the two foods that contribute the least to climate change, while lamb and beef contribute the most. In what may come as a surprise to vegetarians, cheese is ranked third-worst — more damaging to the climate than pork and poultry. According to the analysis, eating four ounces of cheese has the same carbon footprint as driving a car more than three miles.
This interactive graphic on NOAA’s climate.gov site (scroll down) enables users to compare climate-related variables, such as temperature, carbon dioxide, and ocean heat content, between 1881 and 2011. This side-by-side view allows the user to compare how the variables have changed over time. For example, some climate deniers claim that the sun is responsible for recent warming. But this graphic shows that the sun’s energy has remained relatively constant since 1881, even as the atmosphere and the ocean have warmed.
Gapminder World, owned by Google, is a tool that allows you to create graphics by manipulating dozens of variables, such as a country’s carbon dioxide emissions, average life expectancy, per capita income, and even murder rates. The tool contains data on world carbon dioxide emissions through 2005. If users find a graph they particularly like, they can easily send it to friends and colleagues using the “share” tool.