Climate outlook to 2030

Our forecast for global average temperature to 2030 has been updated for the progression of Solar Cycle 23 and the contribution that will be made by increased carbon dioxide in the atmosphere. The increased length of Solar Cycle 23 supports the view that Solar Cycle 24 will be weak, with the consequence of increased certainty that that there will be a global average temperature decline in the range of 1° to 2°C for the forecast period. The projected increase of 40 ppm in atmospheric carbon dioxide to 2030 is calculated to contribute a global atmospheric temperature increase of 0.04°C. The anthropogenic contribution to climate change over the forecast period will be insignificant relative to natural cyclic variation.