The hiatus in the rise in global temperatures could last for another 10 years. Scientists have struggled to explain the so-called pause that began in 1999, despite ever increasing levels of CO2 in the atmosphere. The latest theory says that a naturally occurring 30-year cycle in the Atlantic Ocean is behind the slowdown.
The researchers says this slow-moving current could continue to divert heat into the deep seas for another decade. However, they caution that global temperatures are likely to increase rapidly when the cycle flips to a warmer phase. According to the Intergovernmental Panel on Climate Change (IPCC), global average temperatures have increased by around 0.05C per decade in the period between 1998 and 2012.
This compares with a decadal average of 0.12 between 1951 and 2012. More than a dozen theories have been put forward on the cause of this pause in temperature growth that occurred while emissions of carbon dioxide were at record highs. These ideas include the impact of pollution such as soot particles that have reflected back some of the Sun’s heat into space. Increased volcanic activity since 2000 has also been blamed, as have variations in solar activity.