Rocket has printed NOAA's global temperature graph and taped it beside the crew's little anomaly chart.
"Ours has ten bars," he says. "Theirs has more than a hundred and seventy."
Raven runs a finger along the bottom. "Blue on the left. Red on the right. What do you notice about the last few decades?"
"The red bars get taller," Rocket says. "And there is no blue at all near the end."
Nova brightens two spots on the graph, one near 1850 and one near 2024. "Read the slope between them," she hints. "Then read only the last fifty years."
Rocket squints. "It is steeper at the end. Much steeper."
"That is what the numbers say too," Raven says, opening the table.
NOAA's page on global temperature, on climate.gov, gives these rates. They come from the combined land and ocean record.
| Period (NOAA) | Warming rate per decade | Total change |
|---|---|---|
| 1850 to 2024 | 0.11 degrees F (0.06 degrees C) | About 2 degrees F in total since 1850 |
| 1975 to 2024 | 0.36 degrees F (0.20 degrees C) | More than three times the long-term rate |
NOAA also reports that 2024 was 2.32 degrees Fahrenheit above the 20th-century average of 57.0 degrees.
The 2024 anomaly was 0.18 degrees Fahrenheit warmer than the previous record, set in 2023.
When the century began, the first year to set a record was 2005. NOAA notes 2005 is now only the 13th warmest year.
NOAA's page on atmospheric carbon dioxide, also on climate.gov, reports how fast the amount in the air has grown each decade.
The modern record began at Mauna Loa Observatory in Hawaii in 1958. Amounts are given in parts per million, or ppm.
| Decade (NOAA) | Average yearly increase in carbon dioxide |
|---|---|
| 1960s | 0.8 ppm per year |
| 1980s | 1.6 ppm per year |
| 1990s | 1.5 ppm per year |
| 2015 to 2024 | 2.6 ppm per year |
In 2024 the global average reached 422.8 ppm, a record. The rise during 2024 was 3.75 ppm, the largest one-year increase on record.
NOAA states that carbon dioxide is now 50 percent higher than before the Industrial Revolution.
NOAA explains why it keeps rising: each year human activities release more carbon dioxide than natural processes can remove.
Natural sinks, mainly plant growth and the ocean, remove about half of what is emitted. The rest stays in the air.
Both tables show the same shape. The rate of change was slower in the earlier rows and faster in the later rows.
NGSS asks you to ask questions that clarify this evidence. A good question connects the two tables.
For example: when the carbon dioxide rate doubled, what happened to the warming rate? Both tables let you check.
Another: if natural sinks remove about half the emissions, why does the amount in the air still rise? NOAA answers that above.
| Reading both tables | True or false? |
|---|---|
| The warming rate since 1975 is more than three times the rate since 1850. | ? |
| Carbon dioxide rose faster in the 1960s than from 2015 to 2024. | ? |
| The modern carbon dioxide record began in 1958 at Mauna Loa. | ? |
| Natural sinks remove all the carbon dioxide people emit each year. | ? |
| Carbon dioxide is now about 50 percent higher than before the Industrial Revolution. | ? |
Careful reading. Tomorrow you look at evidence from ice, sea and sky.