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.
Chart 1 of 2 · Space
How many planets outside our solar system are discovered each year?
The interactive chart needs JavaScript. The numbers are on the chart's page.
Astronomers confirmed 246 new planets around other stars in 2025. The first were found in 1992, and the count leaped in 2014 and 2016 (872 and 1,504), when NASA's Kepler team confirmed hundreds of its candidates at once. The archive counts a planet in the year its discovery was published and keeps adding late confirmations, so recent years can still rise.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: NASA Exoplanet Archive, Planetary Systems Composite Data (Public domain (NASA data); this research has made use of the NASA Exoplanet Archive, operated by Caltech under contract with NASA) · Data as of Dec 31, 2025
Open the chart and its numbersChart 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
- Compare the United States, China and India. Which emits the most per person, and is that the one that emits the most in total?
- Why might some small countries have the highest figures on the chart?
- Which seems fairer for comparing countries' share of the blame for climate change, total emissions or emissions per person? Why?
Source: World Bank, World Development Indicators: Carbon dioxide (CO2) emissions excluding LULUCF per capita (t CO2e/capita) (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2024
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