claim: The costs of inaction far outweigh the costs of mitigation.
evidence: Scenario B1 Best estimate temperature rise of 1.8 °C with a likely range of 1.1 to 2.9 °C (3.2 °F with a likely range of 2.0 to 5.2 °F) Sea level rise likely range [18 to 38 cm] (7 to 15 inches) Scenario A1T Best estimate temperature rise of 2.4 °C with a likely range of 1.4 to 3.8 °C (4.3 °F with a likely range of 2.5 to 6.8 °F) Sea level rise likely range [20 to 45 cm] (8 to 18 inches) Scenario B2 Best estimate temperature rise of 2.4 °C with a likely range of 1.4 to 3.8 °C (4.3 °F with a likely range of 2.5 to 6.8 °F) Sea level rise likely range [20 to 43 cm] (8 to 17 inches) Scenario A1B Best estimate temperature rise of 2.8 °C with a likely range of 1.7 to 4.4 °C (5.0 °F with a likely range of 3.1 to 7.9 °F) Sea level rise likely range [21 to 48 cm] (8 to 19 inches) Scenario A2 Best estimate temperature rise of 3.4 °C with a likely range of 2.0 to 5.4 °C (6.1 °F with a likely range of 3.6 to 9.7 °F) Sea level rise likely range [23 to 51 cm] (9 to 20 inches) Scenario A1FI Best estimate temperature rise of 4.0 °C with a likely range of 2.4 to 6.4 °C (7.2 °F with a likely range of 4.3 to 11.5 °F) Sea level rise likely range [26 to 59 cm] (10 to 23 inches) "Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium, due to the timescales required for removal of this gas from the atmosphere."