Question

part 1: graphing climate data and identifying patterns
lets look at how the average global temperatures have changed over time alongside some variables known to influence climate, such as the volcanic aerosol index (values represent relative stratospheric particles, not the number of eruptions), concentration of co₂ in the atmosphere, and the average number of sunspots (which correlates with solar activity). take a look at the table below and the values for each variable over time. answer the questions below.

year	average global temp. (°c)	volcanic aerosol index	co₂ concentration (ppm)	average # of sunspots
1965	14.0	0.05	320	75
1970	14.0	0.08	325	105
1975	14.0	0.04	331	18
1980	14.1	0.12	339	155
1985	14.2	0.03	348	10
1990	14.3	0.15	354	145
1995	14.4	0.09	361	18
2000	14.5	0.05	369	120
2005	14.7	0.02	378	30
2010	14.8	0.04	389	10
2015	15.0	0.03	401	80
2020	15.2	0.01	414	10
2025	15.3	0.02	419	65

1. without graphing the data, what patterns or trends do you observe in the data table?

1. which of the three variables correlates most closely with global temperatures?

1. choose one variable above to plot along with the temperature data on the graph below. write the name of the variable you choose on the line provided, and make sure to include an appropriate scale on the right - side y - axis.

Explanation:

1. For the first question: Observe the direction of change for each variable across the years. Average global temp and CO₂ concentration show a steady upward trend. Volcanic aerosol index has no consistent upward/downward trend, fluctuating up and down. Average sunspot count also fluctuates without a steady long-term upward or downward trend.
2. For the second question: Compare the trend alignment with average global temperature. CO₂ concentration increases consistently as global temperature rises, while the other two variables fluctuate irregularly, so CO₂ concentration has the closest correlation.
3. For the third question: Any of the three variables is acceptable; here we select CO₂ concentration as it has the clearest correlation with temperature, and an appropriate scale for it would be 310 to 420 ppm (matching the range in the table).

Answer:

1. - Average global temperature shows a consistent increasing trend over the years, rising from 13.9°C in 1960 to 15.3°C in 2025.

• Atmospheric CO₂ concentration also has a steady upward trend, increasing from 317 ppm in 1960 to 419 ppm in 2025.
• Volcanic aerosol index and average number of sunspots show no consistent long-term trend, instead fluctuating up and down across the measured years.

1. CO₂ Concentration (ppm)
2. Variable chosen: CO₂ Concentration (ppm); Appropriate right y-axis scale: 310, 330, 350, 370, 390, 410, 430 (covering the range of CO₂ values in the table)