Category Archives: Science and Society

Four graphs that suggest we can’t blame climate change on solar activity

The past decade (2010-2019) was the hottest on record and five of the top 10 warmest single years have all occurred since 2015, according to reports released by the UK Met Office and the World Meteorological Organisation.

The current Australian bushfire crisis is also the worst on record, having emerged due to a combination of increased average temperature (roughly 1.5°C above the long term average) and a reduction in rainfall.

But can we attribute this to anything more natural than anthropogenic effects? Solar activity, for example, has previously been linked to temperature and is sometimes blamed for climate change. But our new analysis provides evidence for why this isn’t the case.

The sun is the dominant source of energy for the Earth’s climate, so quantifying what influence it has had on global temperatures since industrialisation is very important.

Like all stars, the sun undergoes variations in solar activity, meaning its energy output varies with time. The visible surface of the sun (which you should never look at directly) is called the photosphere. When imaged, it appears as a white disk which is occasionally blotted by the appearance of sunspots.

These sunspots are regions of intense magnetic fields that restrict the movement of gas and cause it to cool, making these areas appear dark. However, these same intense magnetic fields connect the visible sunspots on the photosphere with active regions we can’t see. These are areas of gas thousands of kilometres above the visible surface that are superheated to millions of degrees. Such active regions emit light very strongly in ultra-violet and x-ray radiation.

The oldest and easiest way of approximating solar activity at any given time is to simply count the number of sunspots visible on the photosphere. The more sunspots, the more solar activity, and hence the greater overall emission of ultra-violet and x-rays. These emissions are largely absorbed by the Earth’s atmosphere before they reach the ground, causing heating (although some studies suggest the situation is more complicated).

Like our planet, the sun also has a magnetic field that extends outwards. The solar magnetic field defines the size of the solar system and can deflect incoming charged particle radiation from space, called cosmic rays. These cosmic rays have been linked with the Earth’s atmospheric chemistry, seeding cloud formation and extreme lightning storms, meaning they affect temperature and weather.

The number of sunspots rises and falls as part of a roughly 11-year solar activity cycle. There are many sunspots – and more associated emissions of UV and X-rays – at solar maximum and few or even no sunspots at solar minimum.

The solar magnetic field also varies in strength with this solar cycle. It is weakest at solar minimum and strongest at solar maximum. When the solar magnetic field is weak, more cosmic rays can reach the Earth’s atmosphere and affect the climate (as well as the radiation environment of space).

Our current cycle

Some of the earliest scientific sunspot observations were made by Galileo Galilei in the 1610s. From the 1700s, such observations became more regular. They constitute one of the longest historically continuous data sets in all of science. The first observed solar cycle (1755-1766) is called solar cycle 1, the next solar cycle 2, and so on. The most recent is solar cycle 24, which officially began in December 2008 and is still ongoing. We are rapidly approaching the next solar minimum, which is expected in the next year or so.

Solar cycle 24 is unusually weak, with a relatively low number of sunspots, compared to previous cycles. The last one this weak was solar cycle 14, which began in January 1902.

If solar activity did play a significant role in recent changes in global temperatures, then those temperatures should have stayed roughly the same or even declined over the last decade. A paper from 2012 even predicted there would be a 1.0°C decrease in temperatures. Clearly this has not turned out to be the case. The hottest decade on record has coincided with the weakest solar cycle for over a century.

Given this combination of factors, it is rather difficult to defend the position that solar activity is indeed responsible for present climate change without a radical shake up of the understanding of solar physics. In the graphs below we have attempted to correlate the number of sunspots with variations in global sea surface temperatures (taken from the Japan Meteorological Agency), and global surface temperatures (taken from GISTEMP data).

The top panels show the warming trend and sunspot number over time. Our analysis reveals no significant correlation between solar activity, based on sunspot number, and atmospheric or sea surface temperatures over the last century. The divergence between sunspot number and temperatures is particularly apparent in the most recent solar cycle.

The lower panels show scatter plots of the number of sunspots against temperature, and again no clear relationship is visible. You can work out mathematically how good the correlation is by measuring how close the datapoints are to a straight line. In such a calculation, a value of 0 suggests the data is random noise and a value of 1 represents a perfect correlation. We got values of between 0.09 and 0.04, which suggests that the variation is largely due to factors other than solar activity.

When looking at global temperatures, the average value serves as a baseline and any observed difference from this is called a temperature anomaly. It is clear from the lower panels that increasing the sunspot number has little discernible effect on the global temperature anomaly. If it did, we would see points clustered around a line sloping upwards to the right in each plot.

These observations of the present solar cycle make it very difficult to defend the position that solar activity is ultimately responsible for the world’s current warming trend. Instead they fit with the argument that human influences are responsible for a large amount of the recent increase in global temperatures.

While the sun is responsible for the overall climactic conditions on Earth, there has not been enough of a long-term difference in solar activity since industrialisation to fully explain our current global warming trend.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

Source: The Conversation: Technology http://theconversation.com/four-graphs-that-suggest-we-cant-blame-climate-change-on-solar-activity-130154

Polygraph lie detector tests: can they really stop criminals reoffending?

The UK government recently announced it was planning to increase the use of polygraphs to monitor offenders on probation, specifically those convicted of terrorist offences.

This is one of several new measures to prevent a repeat of the recent London Bridge attack, which was committed by an offender out in the community on license. One difficulty with deciding which offenders can be released this way is that offenders can lie about their actions, thoughts and intentions to convince probation officers that they pose a low risk.

The government hopes that an increased use of polygraphs will help identify terrorists planning to reoffend. But are polygraphs actually able to do this?

Polygraphs are already in use in the UK for probation purposes. Since 2014, high-risk sex offenders have had to undergo polygraphs testing as part of their license conditions. Sex offenders are also routinely asked to undergo polygraphs in the US, but the practice is not common in other countries.

Although polygraphs are sometimes known as lie detectors, they don’t actually detect lies directly. Most modern polygraphs measure the interviewee’s heart rate, breathing rate and sweating while they are asked yes/no questions. These questions need to be simple and refer to a concrete event that is known by the interviewer. This makes it hard to use polygraphs to ask people what they plan to do in the future, because we don’t know enough to know the right questions to ask.

The polygraph picks up on any changes in breathing, heart or sweat rate during the interview. These changes can happen for many reasons. Sometimes a response is caused by the stress of lying. Sometimes they are an “orienting response”, people responding to something familiar or important to them.

This can be helpful to show that somebody knows something that they said they didn’t know (“guilty knowledge”). However, strong polygraph responses may also be due to shock or upset at the question or nervousness about the polygraph itself.

Better than average

So how accurate are polygraphs in actually detecting lies? There have been several reviews of polygraph accuracy. They suggest that polygraphs are accurate between 80% and 90% of the time. This means polygraphs are far from foolproof, but better than the average person’s ability to spot lies, which research suggests they can do around 55% of the time.

However, many of these polygraph studies involved people lying about clearly defined events in controlled experiments. It is possible that polygraphs are less accurate in real life probation cases. One study from 2006 attempted to estimate the accuracy of the polygraph with US sex offenders, but it relied on the offenders saying when the polygraph was wrong, which may not be entirely accurate.

Unfortunately, we don’t know how often probation officers suspect that offenders are lying and how good they are at identifying lies. So, we don’t know whether polygraphs are better than probation officers.

There are also concerns about when the polygraph is wrong. The test can be beaten by liars with knowledge of how polygraphs work and are used. These people may also be the ones that the probation officers are most interested in catching. They may have practised how to beat polygraphs precisely because they have very serious things to hide.

Some studies show that polygraphs are worse at detecting that people are telling the truth than detecting they are lying, in some cases indicating deception for almost half of the people who are actually telling the truth. This can be especially difficult to deal with in probation situations, where an offender may have no opportunity to prove that they were not lying when the polygraph indicates they are. How do you prove that you weren’t planning to reoffend?

Encouraging truth telling

However, there is another use for polygraphs in probation. They encourage people to confess. Forensic psychologist Theresa Gannon and her colleagues studied this on UK sex offenders in 2014. They found that offenders were more likely to disclose something of interest when using the polygraph (75%, instead of 51% without). This disclosure often happened after the polygraph had indicated deception. It may be that offenders feel forced to make a confession after failing the polygraph. However, the study could not tell whether these confessions are true.

After failing a polygraph, offenders may feel that further denials won’t be believed and confessing is best, even when they were not lying. This research suggests that the polygraph can be used to psychologically pressure offenders into disclosing self-incriminating information. Information that may not even be true.

So, is it a good idea for the government to increase polygraph use to monitor offenders? Research shows that they are nowhere near foolproof, but they may have some usefulness as a potential indicator of deception and to encourage truth telling.

However, using them raises several ethical questions. For example, it is fair to use them to try and extract self-incriminating statements?

Some people may argue that something is better than nothing and polygraphs are the best we’ve got. But in instances where polygraphs are so inaccurate that they give probation officers more useless than useful information, nothing may be better than something.

Lara Warmelink does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Source: The Conversation: Technology http://theconversation.com/polygraph-lie-detector-tests-can-they-really-stop-criminals-reoffending-130477

Race to the bottom of the sea – the little known heroes of the 20th century’s ‘inner space race’

On January 23 1960, Jacques Piccard and Don Walsh climbed into an undersea craft called Trieste and dived nearly 11 kilometres to the deepest point in the ocean – the Challenger Deep of the Mariana Trench in the Pacific Ocean.

Down there, no sunlight can reach and the water is only ever a few degrees above freezing. The water pressure outside the walls of their vessel was 1,000 times greater than at the surface, but Piccard and Walsh overcame these conditions to enter history as the first Challenger Deep voyagers.

The first men to traverse these alien reaches of our world are much less well known than the first astronauts to walk on the Moon. Still, the race they led to the deepest point on Earth’s surface has profound implications for the modern world. The story of the earlier deep-sea pioneers whose achievements led to their dive is seldom told either, so who were the first “bathynauts” to visit the ocean depths?

Read more: Anthill 15: Unexplored places

Beebe and Barton’s bathysphere

William Beebe and Otis Barton became the first bathynauts in the early 1930s, diving in the “bathysphere” that Barton designed. In common with later deep-sea vehicles, the bathysphere had a strong metal hull to resist the pressure of the deep ocean, allowing those inside to remain at normal atmospheric conditions and avoid the need to decompress like scuba divers.

Beebe and Barton dived to 435 metres in 1930, and in 1932 they broadcast live from 671 metres down to listeners of NBC and BBC radio across the US and Europe. Finally, in 1934 they reached 923 metres deep, as Beebe described in his book “Half Mile Down”.

Beebe and Barton’s colleague Gloria Hollister became the first female bathynaut, diving to 368 metres deep in the bathysphere in 1934. Hollister remained the world’s deepest diving woman for several decades, as naval traditions that excluded women from submarines spilled over to ocean exploration during the cold war. Meanwhile, Barton went on to design another craft called the “benthoscope” to venture deeper than the bathysphere, and on August 19 1949 he set a new depth record of 1,372 metres inside it.

The bathysphere and benthoscope both dangled on a cable from a ship on the surface, which limited their manoeuvrability. But Swiss physicist and inventor Auguste Piccard, who had soared to record-breaking altitudes in the pressurised capsule of a balloon in the early 1930s, realised that the principles of an airship could be adapted to create a new type of undersea vehicle. Instead of using a cable to lower and raise the craft, Piccard’s “bathyscaphe” used detachable ballast weights and a buoyancy tank filled with lighter-than-water petrol, similar to the helium-filled envelope of an airship.

The first bathyscaphe was named FNRS-2 after Belgium’s Fonds National de la Researche Scientifique (FNRS), who paid for it. The craft was ready for testing in 1948, but ran into difficulties after an unoccupied test dive to 1,400 metres.

Piccard asked for more funds for another attempt, and his Belgian backers struck a deal with the French Navy, who were interested in developing the bathyscaphe further, eventually christening the rebuilt craft “FNRS-3”. But Piccard went his own way, working with his son Jacques to raise money from European industrialists for a new bathyscaphe, which they named the “Trieste”. On September 30 1953, father and son set a new depth record of 3,150 metres in the Trieste – and Auguste Piccard became the first person to explore the stratosphere and the deep ocean.

Back to the bottom

The French Navy pipped the Piccard’s record on February 15 1954, reaching 4,050 metres with Georges Houot and Pierre Willm in the bathyscaphe FNRS-3. Willm later designed the bathyscaphe Archimède, which made several dives into ocean trenches during the 1960s and took scientists to the undersea volcanic rift of the mid-ocean ridge for the first time in 1973.

The US Office for Naval Research chartered the Trieste for a series of science dives in the Mediterranean in 1957 – and the Piccards sold the Trieste to the US Navy in 1958, on the condition that Jacques would continue to operate it. The US Navy set the goal of using the Trieste to reach the deepest point in the ocean, which they achieved on January 23 1960 with Jacques and Lieutenant Don Walsh aboard.

Unlike astronauts, the race to the bottom of the ocean happened largely beyond the frenzied competition of cold war superpowers. It was instead driven mostly by private individuals, such as Beebe, Barton and the Piccards. After the record-setting plunge of 1960, deep-diving vehicles became a matter of national capability for science and strategic purposes.

But private citizens have taken up the torch for deep-sea exploration again. Hollywood director James Cameron returned to the Challenger Deep in 2012, while billionaire Victor Vescovo and his expedition team dived there several times in a new vehicle in 2019.

Another kind of “inner space race” is happening today. Governments are trying to extend their territorial rights to ocean resources and stake a claim to future deep-sea mining sites in places beyond national boundaries. Thanks to remote specks of overseas territories such as the Pitcairn Islands, the UK has the world’s fifth largest “exclusive economic zone” of rights to ocean resources – 27 times larger than the UK’s land area – along with licences from the United Nations to explore for manganese nodules in 133,539 square kilometres of the eastern Pacific.

Six decades on from the first dive to the Challenger Deep, the ability of countries to reach anywhere in the deep ocean may be quietly redrawing the geopolitical map.

Jon Copley receives funding from the Natural Environment Research Council.

Source: The Conversation: Technology http://theconversation.com/race-to-the-bottom-of-the-sea-the-little-known-heroes-of-the-20th-centurys-inner-space-race-130251

The civil service doesn’t just need more scientists – it needs a decision-making revolution

The UK government’s chief scientific adviser, Sir Patrick Vallance, recently said he was mounting a drive to recruit more scientists and engineers into the civil service. His comments echo the much-discussed call by the prime minister’s chief special adviser, Dominic Cummings, for more data scientists and other “assorted weirdos” to become civil servants.

From our experience working with and in government departments, we know that there are many problems in how the civil service uses evidence to support decision-making. And scientists (and other specialists from the social sciences and humanities), who value sound methodologies and are trained to search for robust evidence, well-designed studies and research questions, could indeed help with that.

But more scientists working within current systems won’t be enough. We need a transformation in thinking that goes far beyond what degree civil service recruits studied. Some of this can be achieved by building on some excellent practice already underway in many parts of the civil service, for example, the increased use of social science expertise and the valuable role played by department chief scientific advisers.

But here are six further ways the civil service could transform its approach to evidence and decision-making.

Horizon scanning

The process of gathering evidence is more efficient if an issue has been anticipated, but civil servants often work reactively. Academic researchers, on the other hand, regularly carry out “horizon scans” of various issues to identify key forthcoming topics for policy and research.

For example, a recent horizon scan of conservation issues found the increasing use of traditional Asian medicine, the use of artificial wombs, and the impact of the shrinking ozone hole on Antarctic sea ice could all be important issues to consider in 2020.

All government departments could ensure they routinely look ahead by reflecting on existing horizon scans and encourage further scans in missing subject areas. There is a dedicated horizon scanning team in the civil service already, and increasing its activity could benefit all aspects of government.

Consider all the options

When decision-makers are blinkered by convention, a restricted formulation of the problem or narrow self-interest, they may overlook better policy alternatives. Horizon scanning provides a measure of protection against this myopia, but civil servants can also work with outside experts, businesses, charities and other organisations to broaden the scope of scenarios they consider.

Listening to as diverse a suite of perspectives on the problem as possible is particularly important, because research has shown that diverse thinking brings new ideas. This is why Dominic Cummings wants to recruit more “misfits and weirdos”, because a greater variety of thinking could produce more alternative policy solutions.

Collate evidence properly

There can often be problems gathering timely, suitable evidence to inform policymaking. But the civil service also has problems with its institutional culture when it comes to storing and using rigorous evidence. Based on our own secondment experience, we’ve seen that it can be difficult simply to find the evidence that exists in the ether of government IT infrastructure, even when it comes from research commissioned by the civil service. This either slows down decision-making or results in the same evidence-gathering exercises being repeated.

Things that could address this problem include routinely carrying out reviews of all relevant available evidence on a topic (known as subject-wide evidence synthesis), academic partnerships to fill critical knowledge gaps, and simply summarising evidence from previously commissioned research and evidence-gathering exercises. Producing clearly indexed summary paragraphs in accessible language (as done by the Conservation Evidence journal) would make it easier for new staff to find evidence and build institutional memory of previous research, even when staff move on to new jobs.

Evaluate evidence quality

Not all evidence is created equal. Research shows that how a study is designed considerably affects the accuracy of its results. What’s deemed “good” evidence can often be questionable. And “scientific” evidence isn’t necessarily more valuable than other forms, such as experience.

Civil servants may not be skilled at assessing these kinds of issues, which can affect the quality of evidence they use. So more need to be given an understanding of the basic elements of interpreting evidence. This includes bias, chance, pseudoreplication (repeating tests with the same subjects to bulk out your data), data dredging (selecting data that isn’t typical of the overall pattern) and regression to the mean (the fact that atypical values are likely to be followed by less extreme ones).

Use experts properly

Experts can be repositories of a wealth of useful information and are regularly used by government departments. But scientists’ views can be just as influenced by bias as anyone else’s, and this can affect how they collect and interpret data. In fact, research shows that if experts are used to estimate facts or to judge the outcomes of future events, the most highly regarded scientist is rarely any better than a relatively recent graduate.

Instead of relying on highly regarded individuals and the culture of scientific authority that goes with them, civil servants should seek a diverse set of independent estimates. They should collate the data with appropriate statistical procedures and form an overall scientific judgement. To make sure civil servants get their interactions with experts right, they should use skilled in-house science brokers.

Adopt effective decision-making techniques

Transparent decision-making and reducing bias are hallmarks of evidence-based policymaking. Yet a report published in 2018 found that, despite some improvements in transparency, many government departments did not routinely publish the evidence underlying new policies. It is often unclear how decisions are made.

A step change is needed to make the most of proven group decision-making processes designed to limit bias and increase transparency, such as the Delphi technique. And this is one area where civil servants with scientific training really could make a difference, by helping separate facts and values, and orchestrating the discussion of trade-offs between policy options.

These changes wouldn’t be hard to introduce and many civil servants would agree they would help. But they also complain that there isn’t the time to make the changes. Instead of looking for a special fix, the civil service needs to overcome its institutional inertia and make these changes happen.

David Rose receives funding from the ESRC.

Mark Burgman receives funding from UKRI, the Australian Research Council and DARPA.

William Sutherland receives funding from Arcadia, David and Claudia Harding Foundation, MAVA and NERC.

Source: The Conversation: Technology http://theconversation.com/the-civil-service-doesnt-just-need-more-scientists-it-needs-a-decision-making-revolution-130256