Chart assignment

Charts to read and discuss

Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.

  1. How do countries compare on wealth, health and the internet?
  2. How much has the US warmed since 1895?
  3. How long do Americans live, and how has that changed since 1900?
  4. How much rarer is each step up in earthquake magnitude?

Chart 1 of 4 · World

How do countries compare on wealth, health and the internet?

The interactive chart needs JavaScript. The numbers are on the chart's page.

Pick countries and compare them on GDP per person, population, life expectancy, internet use, access to electricity, unemployment, inflation, carbon emissions per person, health spending per person or college enrollment. It opens with GDP per person in 2024: $86,170 in the United States, $56,104 in Germany, $13,293 in China, $2,592 in India and $1,084 in Nigeria. Each measure uses the newest year most countries have reported; GDP is in US dollars at that year's exchange rates, not adjusted for prices.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: World Bank, World Development Indicators: GDP per capita (current US$) (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2024

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Chart 2 of 4 · Climate

How much has the US warmed since 1895?

The interactive chart needs JavaScript. The numbers are on the chart's page.

The contiguous US averaged 54.6°F in 2025. The warmest year since records began in 1895 was 2024, at 55.5°F. Through 2025, the dashed trend line, the straight line that best fits every year, rose about 0.18°F a decade, or 2.3°F since 1895, and warming had sped up to about 0.5°F a decade since 1970. Alaska and Hawaii aren't included.

How to read this chart

Each point is one year's average temperature across the lower 48 states, in degrees Fahrenheit. The axis doesn't start at zero, so a small rise looks steep: read the numbers on the axis, not the height of the line. The dashed line is the trend, the straight line that best fits every year; single years bounce above and below it.

Questions to discuss

  1. Find the warmest and coolest years on the chart. How many degrees apart are they?
  2. Why might one year be much cooler than the year before, even while the trend line keeps rising?
  3. The axis doesn't start at zero here, but bar charts always do. Why is that fair for temperatures but not for bars?

Source: NOAA National Centers for Environmental Information, Climate at a Glance (Public domain (U.S. government work)) · Data as of Dec 31, 2025

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Chart 3 of 4 · Health

How long do Americans live, and how has that changed since 1900?

The interactive chart needs JavaScript. The numbers are on the chart's page.

A baby born in the US in 2018 could expect to live 78.7 years, up from 47.3 in 1900. The sharpest drop was in 1918, to 39.1 years, during the influenza pandemic. This CDC dataset stops at 2018; later NCHS reports put life expectancy at 78.4 years in 2023 and 79.0 in 2024, after a fall during the COVID-19 pandemic.

How to read this chart

Each point is how long a baby born in that year could expect to live, if death rates stayed as they were that year. It is an average, so it is pulled down a lot when many babies and young people die. Hover or tap a point to read its year and value.

Questions to discuss

  1. Find the sharpest drop on the chart. What happened in the world that year?
  2. Life expectancy in 1900 was under 50. Does that mean most adults died in their 40s? What else could lower the average?
  3. What changes in medicine, food or public health could explain the long rise?

Source: CDC National Center for Health Statistics, Death rates and life expectancy at birth (Public domain (U.S. government work)) · Data as of Dec 31, 2018

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Chart 4 of 4 · Earthquakes

How much rarer is each step up in earthquake magnitude?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In 2025 the world recorded 6,428 earthquakes of magnitude 4.5 to 4.9, 1,983 of magnitude 5, 129 of magnitude 6, 15 of magnitude 7 and 1 of magnitude 8 or more. Each step up in magnitude is roughly ten times rarer, and releases about 32 times more energy. Countless smaller quakes go unrecorded worldwide, so the chart starts at 4.5.

How to read this chart

Each bar counts the earthquakes recorded worldwide in one year within a range of magnitudes. The bars start at zero. Each whole step up in magnitude releases about 32 times more energy, so a magnitude 7 quake is far more than one step stronger than a 6.

Questions to discuss

  1. Roughly how many times more common is each band than the one above it?
  2. The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?
  3. The chart starts at magnitude 4.5. Why might smaller earthquakes around the world go uncounted?

Source: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat) (Public domain (U.S. government work); source U.S. Geological Survey) · Data as of Dec 31, 2025

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