It has warmed about 1°C (1.8°F) over the past century, and is predicted by the United Nations’ climate panel (IPCC) to warm between 1.6-3.8°C (2.9-6.8°F) during this century, mainly owing to increased CO2. An average of all 38 available standard runs from the IPCC shows that models expect a temperature increase in this decade of about 0.2°C.