Carbon dioxide: Correlation
Prices it moves with, and why
Merchant carbon dioxide is mostly captured as a by-product of ammonia, hydrogen and ethanol plants, then purified and liquefied. Prices are set in long contracts with gas suppliers, so they rise in steps and jump when source plants shut.
Price index US PPI: carbon dioxide index (BLS base period) · monthly, Jan 2006 to Sep 2026What its price moves with
Selected linkCarbon dioxide and Ammonia
Monthly changes -0.09 little or none correlation 12-month changes 0.11 little or none correlation Last 5 years -0.40 monthly changes Lead or lag +6 mo Ammonia tends to lead by 6 months (r 0.16) Price function, Jan 2006 to Sep 2026 Carbon dioxide ≈ 3.76 × (Ammonia)0.76 R² 0.32 On this fit, a 10% higher ammonia price goes with a 7.5% higher carbon dioxide price over the long run. Units: index (BLS base period) and index (BLS base period).Chart: Carbon dioxide and Ammonia prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Carbon dioxide price against Ammonia price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Ammonia plants are a main CO2 source, so when high gas prices close them, as in Europe in 2022, CO2 gets scarce and dearer. The two can move in opposite directions: -0.09 monthly and -0.40 over the last five years.
little or none co-movement month to month · 248 months Show chartsFermentation at ethanol plants gives a pure CO2 stream, a key source in the US and Brazil. The ethanol index moves with the CO2 index at only 0.05 monthly and 0.22 yearly, because CO2 prices are fixed in long supply contracts.
little or none co-movement month to month · 248 months Show chartsHydrogen and ammonia made from gas release CO2 as a by-product, and gas prices decide whether those plants run. European gas moves with the CO2 index at only 0.10 monthly and 0.15 yearly, reflecting contract pricing.
little or none co-movement month to month · 248 months Show chartsThe same industrial gas companies sell CO2, nitrogen and oxygen by tanker and cylinder, sharing delivery and contract terms. The industrial gases index moves with the CO2 index at 0.30 monthly, its strongest monthly tie.
weak co-movement month to month · 248 months Show chartsPurifying and liquefying CO2 uses electricity for compression and refrigeration. The industrial power index moves with the CO2 index at 0.09 monthly, rising to 0.40 over the last five years.
little or none co-movement month to month · 248 months Show chartsSynthetic fuels such as e-methanol and e-kerosene need a carbon source, which could add large new demand for captured CO2. This use is still small and has no price series, so the link is shown as text.
Not enough overlapping price history to measure.How to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.