Table 3.
Projected global yields of TFA from HFC-134a and HFO-1234yf and total deposition between 2020 and 2100
| HFC-134a | HFO-1234yf | Sum | |
|---|---|---|---|
| Annual formation of TFA (a. e., acid equivalents) | |||
| 2020 | 0.01–0.03 Tg year–1 | 0.03–0.03 Tg year–1 | 0.04–0.06 Tg year–1 |
| 2050 | 0.02–0.05 Tg year–1 | 0.34–0.49 Tg year–1 | 0.36–0.54 Tg year–1 |
| 2100 | 0.01–0.02 Tg year–1 | 0.63–1.03 Tg year–1 | 0.64–1.05 Tg year–1 |
| Sums of deposited TFA (a. e.) | |||
| 2020–2050 | 0.5–1.5 Tg | 5.3–6.6 Tg | 5.8–8.1 Tg |
| 2020–2100 | 1.0–2.9 Tg | 30.5–49.0 Tg | 31.5–51.9 Tg |
|
Concentration of TFA as the sodium salt in the oceans in |
2050 | 244–246 ng L−1 | |
| 2100 | 266–284 ng L−1 | ||
These data are taken from Table 7.3 of the 2022 report of the Science Assessment Panel [212] and currently are best estimates for the two listed refrigerants. Releases of other potential sources of TFA (see Fig. 12) have not been included but are expected to be much smaller. Estimated future concentration in the oceans is based on the nominal value of 200 ng a.e. L−1 in 2020 and a total volume of 1.36 × 109 km−3. For comparison to toxicity values, concentrations have been converted to sodium salt