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 often do NFL teams go for it on fourth down?
  2. How much carbon dioxide does each country emit per person?

Chart 1 of 2 · NFL

How often do NFL teams go for it on fourth down?

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

NFL offenses went for it on 23.3% of fourth downs in the 2025 regular season, against 11% to 14% in every season from 1999 to 2017. The rest were punts and field goal tries. Fake punts and fake field goals count as going for it; plays wiped out by a penalty are not counted. The chart starts in 1999, the first season in nflverse's data.

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: nflverse, NFL play-by-play (nflverse-data) (CC BY 4.0 (nflverse)) · Data as of Jan 4, 2026

Open the chart and its numbers

Chart 2 of 2 · World

How much carbon dioxide does each country emit per person?

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

In 2024, people in the United States emitted 13.6 tonnes of carbon dioxide each, in China 9.3 and in India 2.2, against 4.7 worldwide. The highest figure was 82.8 tonnes in Palau, then Qatar (47.3) and Bahrain (23.9). Search 203 countries and territories. The figures count carbon dioxide from burning fuel, industry and other sources, but not from changes in land use such as cutting forests; in a small country, a few power plants, refineries or fuel sales spread over few people can make the figure very high.

How to read this chart

Each bar is the carbon dioxide a country put into the air in a year, divided by its population, in tonnes per person. The dashed line is the world. A country can emit a lot in total but little per person if it has many people, and a tiny country with a refinery or power plant can top the list.

Questions to discuss

  1. Compare the United States, China and India. Which emits the most per person, and is that the one that emits the most in total?
  2. Why might some small countries have the highest figures on the chart?
  3. Which seems fairer for comparing countries' share of the blame for climate change, total emissions or emissions per person? Why?

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