Climate change 'not affected by solar activity'

Variations in heat from the sun are not a key influence in the advancement of climate change, according to a new study. Researchers have found that global warming is not overly influenced by differences in heat from the sun, largely disproving what was previously thought to be the case.

Historic research has led to the theory that large cold periods or extended warm weather are caused, in some part, by variations in temperature due to solar activity. However, new research has disproved this and suggests that something very different has been responsible for climate change.

Researchers looked at possible causes of global warming over the last 1,000 years in the northern hemisphere. They found that up until 1800, the most influential impact upon global temperatures was actually volcanic eruptions. 

According to the researchers, volcanic eruptions - which create large amounts of volcanic ash - meant that sunlight is unable to reach the Earth, resulting in colder and drier weather. After this time period, industry and the emissions it causes has been the driving force behind climatic changes. 

These new findings reveal that times of low sun activity do not necessarily have a large impact on global temperatures. The latest discovery is also expected to further the understanding of climate change and help with future forecasting of its effects.

The study was carried out by scientists from the University of Edinburgh and used past temperature records, which were aided by information from a number of historic sources, including tree rings. The collected data was compared to computer-based temperature models, which included changes in the sun - both major and minor.

It was found that the weaker alterations in the sun's activities correlated with the temperature records, suggesting that over the past millennium, changes in solar activity have had very little effect on global temperature.

Dr Andrew Schurer, from the University of Edinburgh's School of GeoSciences, said: "Until now, the influence of the sun on past climate has been poorly understood. We hope that our new discoveries will help improve our understanding of how temperatures have changed over the past few centuries, and improve predictions for how they might develop in future. Links between the sun and anomalously cold winters in the UK are still being explored."