1 July 2015, The Guardian, More evidence that global warming is intensifying extreme weather: A new study finds that global warming is causing weather whiplash. Just this week, a new article appeared in the journal Nature that provides more evidence of a connection between extreme weather and global warming. This falls on the heels of last week’s article which made a similar connection. So, what is new with the second paper? A lot. Extreme weather can be exacerbated by global warming either because the currents of atmosphere and oceans change, or it can be exacerbated through thermodynamics (the interaction of heat, energy, moisture, etc.). Last week’s study dealt with just the thermodynamics. This week’s study presents a method to deal with both. The authors, Daniel Horton, Noah Diffenbaugh and colleagues used a new technique to tease apart the complex influences of warming on changes to atmospheric circulation. Read More here
Category Archives: The Science
29 June 2015, Climate News Network, Stress on water resources threatens lives and livelihoods. Satellite data raises red-flag warning about the draining of underground aquifers to meet the demands of expanding populations. The planet’s great subterranean stores of water are running out – and nobody can be sure how much remains to supply billions of people in the future. Satellite instruments used to measure the flow from 37 underground aquifers between 2003 and 2013 have revealed that at least one-third of them were seriously stressed – with little or almost no natural replenishment. The research was conducted by scientists from California and the US space agency NASA, who report in the journal Water Resources Research that they used data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites to calculate what is happening to aquifers. Read More here
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
22 June 2015, The Carbon Brief, Climate change attribution studies are asking the wrong questions, study says. Scientists are calling for a rethink in the way we seek to understand how climate change affects extreme weather. The latest in so-called attribution studies is to study each individual event by itself, looking for how climate change may have made it stronger or more likely. But a new paper says the methods used in many of these studies underestimate the influence of climate change, and suggests a new approach to identify the “true likelihood of human influence”.
One of the first studies to attribute a single extreme weather event to climate change was published just over a decade ago. Researchers showed that climate change had doubled the chances of the record heatwave Europe experienced in 2003. In the years that followed, many more studies have aimed to provide answers on how climate change is affecting our most brutal weather. But while scientists have been able to attribute events caused by temperature extremes, linking other extreme events like storms and heavy rainfall events has proved more difficult, says a new paper in Nature Climate Change. Read More here