23 June 2015, The Carbon Brief, Solar minimum could bring cold winters to Europe and US, but would not hold off climate change. Over the past few decades, our Sun has been relatively active, giving off high levels of the solar radiation that warms the Earth. However, in recent years this peak activity has tailed off, prompting scientists to wonder if the Sun is heading into a period of lower output. A new study says even if the Sun’s activity did drop off for a while, it wouldn’t have much impact on rising global temperatures. But it could mean a higher chance of a chilly winter in Europe and the US, the researchers say.
The Sun’s activity rises and falls on an approximately 11-year cycle, but it can experience longer variations from one century to another. Over the past 10,000 years, the Sun has hit around 30 periods of very high or very low activity – called ‘grand maxima’ and ‘grand minima’. One of these occurred between 1645 and 1715, when the Sun went through a prolonged spell of low solar activity, known as the Maunder Minimum. This didn’t have much of an effect on global climate, but it was linked to a number of very cold winters in Europe. In 2010, scientists predicted an 8% chance that we could return to Maunder Minimum conditions within the next 40 years.
But since that study was published, solar activity has declined further, and this likelihood has increased to 15 or 20%, says new research published today in open-access journal Nature Communications. In fact, the Sun’s output has declined faster than any time in our 9,300-year record, say the researchers. And so they set out to analyse what this could mean for global and regional climate. The researchers used a climate model to run two scenarios where solar activity declines to a grand minimum. They then compared the results with a control scenario where the Sun continues on its regular cycle. For all model runs they used the RCP8.5 scenario to account for future climate change – this is the scenario with the highest greenhouse gas emissions of those used by the Intergovernmental Panel on Climate Change ( IPCC). Global emissions are currently tracking just above this scenario. Read More here