If you read The Australian newspaper the other day, you might be forgiven for thinking a new study into the amount of energy coming from the sun had found that the chances of the world experiencing another “little ice age” had gone up.
You might think that because that’s what the newspaper’s environment editor wrote.
Here are the first two paragraphs, under the headline “Chances of little ice age on the rise“.
The sun’s power is weakening at its fastest rate in 9300 years, doubling the odds of a return to little ice age conditions by mid-century, according to research by the British Met Office.
The chance of a repeat of conditions that last occurred between 1645 and 1715 when London’s Thames River regularly froze over and became the scene of winter fairs, was now rated at between 15 and 20 per cent, up from 10 per cent in 2010.
The big problem with these two sentences, is that the study did not look at the chances of the world, or even parts of the world, “returning to little ice age conditions”.
Rather, the study referred to the chances of the sun having a prolonged period of low solar activity similar to a period known as the Maunder Minimum, which coincided with the Little Ice Age but might not necessarily have actually caused it.
The study was published in Nature Communications and amazingly (or not surprisingly if you have followed much of Lloyd’s work over the years) it doesn’t even mention the Little Ice Age. So what does it say?
The study looked at the chances of the sun falling into a lull and then asked what might happen to global temperatures if this happened. Here’s the relevant bit from the abstract:
An 8% chance of a return to Maunder Minimum-like conditions within the next 40 years was estimated in 2010 (ref. 2). The decline in solar activity has continued, to the time of writing, and is faster than any other such decline in the 9,300 years covered by the cosmogenic isotope data. If this recent rate of decline is added to the analysis, the 8% probability estimate is now raised to between 15 and 20%.
So the study says the chances of the sun falling into a long lull have increased significantly. It doesn’t say anything about a return to “Little Ice Age” conditions. Why?
Because the main part of the study finds that any negative effect that a solar minimum might have on temperatures will be massively outstripped by temperature rises caused by increasing greenhouse gas emissions.
Using a series of climate models, the researchers based at the UK’s Met Office find that between 2050 and 2099, the drop in solar activity would have an impact of -0.12C and -0.13C on global temperatures. The paper states:
This offsets or delays the global warming trend by ~2 years and is small compared with the modelled global warming.
But the paper does suggest that the impact of a solar minimum would be slightly larger in Europe. In a scenario where global temperatures in the region could rise by 6.6C, the drop in solar activity could shave between 0.4C and 0.8C off that warming.
Curiously, later in Lloyds story he actually contradicts his own introduction when he does state the research “found the impact from reduced solar output was a minor cooling effect of about -0.1C”. Lloyd then quotes the met Office scientist Dr Ineson (the quote is the same as the one Ineson gave to a website called reportingclimatescience.com – perhaps that’s where Lloyd got it).
The UK’s Independent newspaper did actually speak to some the scientists. Ineson told The Independent:
This study shows that the Sun isn’t going to save use from global warming, but it could have impacts at a regional level that should be factored in to decisions about adapting to climate change for the decades to come.
The regional impacts of a grand solar minimum are likely to be larger than the global effect, but it’s still nowhere near big enough to override the expected global warming trend due to man-made change.
This means that even if we were to see a return to levels of solar activity not seen since the Maunder minimum, our winters would likely still be getting milder overall.
So the chances of a “little ice age” are not on the rise, as Lloyd’s story claimed, and the study that Lloyd said had showed this, didn’t show that.