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 long do Americans live, and how has that changed since 1900?
  2. Where does US electricity come from?
  3. How much has the US warmed since 1895?

Chart 1 of 3 · 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 2 of 3 · Energy

Where does US electricity come from?

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

In 2025 natural gas made 40.8% of US electricity, followed by nuclear (17.7%) and coal (16.6%). Wind made 10.5% and solar 6.7%. Solar counts only utility-scale plants, not rooftop panels, and the 2025 figures are preliminary.

How to read this chart

Each bar is one energy source's share of all the electricity made in the U.S. in a year, so the bars add up to about 100%. The bars start at zero, so a bar twice as long means twice the share. Solar counts only large power plants, not panels on rooftops.

Questions to discuss

  1. Which source makes the most electricity? About how many times more than the smallest bar?
  2. Which of these sources burn fuel and which don't? What share of electricity comes from each group?
  3. Why might a chart of this kind look different in your state than for the whole country?

Source: U.S. Energy Information Administration, Monthly Energy Review (Table 7.2a) (Public domain (U.S. government work)) · Data as of Dec 31, 2025

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Chart 3 of 3 · 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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