Tag Archives: climate science

In support of Greta Thunberg

This article of mine appeared in The Irish Times last week. I reprint it here for convenience.

‘What’s your take on Greta Thunberg and her school strike?’, a colleague asked me over lunch a few days ago. ‘Wouldn’t she and her followers be better off staying in school’?

Like most people who have been writing about the problem of climate change for some years, I have nothing but admiration for Greta Thunberg.  It’s hard to believe that it is only a year since the diminutive Swede took to absenting herself from school on Friday afternoons in order to sit on the steps of the Swedish parliament, accompanied only by a handwritten placard demanding governmental action on climate change.

But does she really have science on her side?, asked my lunch companion. ‘Or is she some sort of alarmist?’

There is little question that Thunberg has science on her side. Indeed, her demand is not that anyone should listen to her but that they should listen to the climate scientists. It is telling that she began her recent address to the United Nations (an intimidating undertaking for any 16 year-old) by stating that she should not be there. Instead of submitting a written script to accompany her speech, she submitted a chapter of the most recent IPCC report.

But how did her solitary protest become such a big movement?’, my colleague asks. ‘It’s obvious that the movement has been hijacked by the usual collection of eco-loons, anachists and what have you. Who’s paying for all this?’

The growth of Greta’s solitary school strike into a worldwide movement is certainly astonishing. Last month, more than a million schoolchildren worldwide marched in protest. However, there is no evidence the movement has been hijacked or financed by anybody. It seems that a great many of Greta’s contemporaries worldwide have grasped her simple point – the chasm between what they learn in school about the effect of greenhouse gases on global climate and the fact that emissions continue to rise year on year.

‘But the emissions of countries like Ireland and Sweden are negligible in comparison with countries like China. It makes no sense for us to suffer cutbacks while they continue to emit.’

We will never make progress if each nation waits for the other to act. Also, it’s not a given that moving from fossil fuels to renewable energy leads to economic hardship. As it happens, China is now making huge investments in renewable energy.

I’ll bet many of those kids get a lift to school everyday in Daddy’s SUV. And if they’re anything like my lot, they probably have 2 showers a day.’

This is quite possibly true. However, you have to live in the world while trying to change it. While individual actions are important, actions at governmental level are vital. For example, we didn’t address the problem of the hole in the ozone layer by using less deodorant – instead we changed the product.

 ‘ Why can’t they have their marches when school is out?’

One reason is that it wouldn’t be a strike! Presumably, it would be much easier for the students (and their parents) to march on Saturdays, but it would also be much less disruptive.  After all, a postman can refuse to deliver post, and a pilot can refuse to refuse a plane. If schoolchildren want to rause awareness of an issue, they have only one weapon available to them.

‘Don’t talk to me of airplanes – the next time I fly, I can expect delays because some lunatic has glued himself to the roof. By the way, I take it you still fly to conferences?’

I attend very few conferences these days and never in the US – but that’s partly due to a lack of funding for fundamental research. In any case, it’s not the schoolkids who have been targeting aviation – that’s Extinction Rebellion.

‘Ah yes, those guys are determined to make life inconvenient. Ivan Yates compared them to the Taliban the other day’ .

Not a great comparison as Extinction Rebellion is a peaceful protest movement, not a terrorist organization that murders civilians. What XR have in common with the school strikers is a concern for the future. According to the scientists, there is no guarantee that global warming will continue at the current gradual pace. Instead, it is very possible that positive feedbacks will cause the warming to accelerate, rendering some nations uninhabitable due to persistent drought and other nations uninhabitable due to rising sea level. Now that would be inconvenient…

Dr Cormac O’Raifeartaigh lectures in physics at Waterford Institute of Technology and is a Visiting Associate Professor at the School of Physics at UCD. He blogs at www.antimatter.ie

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My favourite conference; the Institute of Physics Spring Weekend

This weekend I attended the annual meeting of the Institute of Physics in Ireland. I always enjoy these meetings – more relaxing than a technical conference and a great way of keeping in touch with physicists from all over the country. As ever, there were a number of interesting presentations, plenty of discussions of science and philosophy over breakfast, lunch and dinner, all topped off by the annual awarding of the Rosse Medal, a highly competitive competition for physics postgraduates across the nation.

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The theme of this year’s meeting was ‘A Climate of Change’ and thus the programme included several talks on the highly topical subject of anthropogenic climate change. First up was ‘The science of climate change’, a cracking talk on the basic physics of climate change by Professor Joanna Haigh of Imperial College London. This was followed by ‘Climate change: where we are post the IPCC report and COP24’, an excellent presentation by Professor John Sweeney of Maynooth University on the latest results from the IPCC. Then it was my turn. In ‘Climate science in the media – a war on information?’,  I compared the coverage of climate change in the media with that of other scientific topics such as medical science and and big bang cosmology. My conclusion was that climate change is a difficult subject to convey to the public, and matters are not helped by actors who deliberately attempt to muddle the science and downplay the threat. You can find details of the full conference programme here and the slides for my own talk are here.

 

Images of my talk from IoP Ireland 

There followed by a panel discussion in which Professor Haigh, Professor Sweeney and I answered questions from the floor on climate science. I don’t always enjoy panel discussions, but I think this one was useful thanks to some excellent chairing by Paul Hardaker of the Institute of Physics.

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Panel discussion of the threat of anthopogenic climate change

After lunch, we were treated to a truly fascinating seminar: ‘Tropical storms, hurricanes, or just a very windy day?: Making environmental science accessible through Irish Sign Language’, by Dr Elizabeth Mathews of Dublin City University, on the challenge of making media descriptions of threats such as storms hurricanes and climate change accessible to deaf people. This was followed by a most informative talk by Dr Bajram Zeqiri of the National Physical Laboratory on the recent redefinition of the kilogram,  ‘The measure of all things: redefinition of the kilogram, the kelvin, the ampere and the mole’.

Finally, we had the hardest part of the day, the business of trying to select the best postgraduate posters and choosing a winner from the shortlist. As usual, I was blown away by the standard, far ahead of anything I or my colleagues ever produced. In the end, the Rosse Medal was awarded to Sarah Markham of the University of Limerick for a truly impressive poster and presentation.

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Viewing posters at the IoP 2019 meeting; image courtesy of IoP Ireland

All in all, another super IoP Spring weekend. Now it’s back to earth and back to teaching…

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No man-made global warming in Ireland, thank you

My letter on global warming in The Irish Times (see post below) got a response from an Irish lobby group called Turn 180. The sub-title of their blog is ‘Humans are not causing global warming’, top marks for clarity there. You can read their objections in their own words here.

The Turn 180 blog got me thinking about why there is so much resistance to the whole idea of an enhanced greenhouse effect. Below are some favourite points:

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Q1. Why do climate scientists keep banging on about recent changes over the last few decades, when everyone knows that, by definition, it is only meaningful to talk about climate over extremely long timeframes?

A. Studies of past climate changes (yes, climate has certainly changed in the past) suggest that once started, climate change tends to happen quite quickly due to feedbacks – with noticeable effects over decades rather than hundreds of years.

Q2. If climate change has occurred in the past, clearly not linked to human activity, why are the boffins so sure it’s different this time?

A. The fact that climate change has had natural causes in the past doesn’t mean it can’t have a man-made cause now. We know greenhouse gases (GHGs) in the atmosphere such as C02 play a major role in regulating the heat of the earth and we know we have increased the GHG concentration by over 40%. It would be very nice to show that this has had no effect on climate, but the evidence points the other way. In particular, measurements of infra-red radiation emerging from the atmosphere into space show it has been steadily decreasing over recent decades. This matches the rise in temp measurements, ice melt and sea-level rise measured worldwide. At the same time, there is no matchup between the recent temp rise and natural cycles  (e.g. studies of sun cycles, earth orbit cycles etc suggest we should be in a cooling cycle).

Q3. Isn’t it true that C02 rise has followed temp rise in past climate change, not vice versa?

A. Yes, but the data also show that once started, a rise in C02 leads in turn to further temp rise. Ouch.

Q4. What’s all this about consensus, hasn’t scientific consensus been wrong in the past?

A. Yes; Scientists like evidence, not ‘he said, she said’. However, if a serious threat to society is perceived (think meteor or alien invasion) the first thing is to find out if the experts are agreed amongst themselves. The IPCC was set up for precisely this purpose, to collate and make sense of the many hundreds of diverse scientific studies of various aspects of global warming. The most striking aspect of the IPCC reports is how closely the studies agree – all this from scientists who like nothing better than proving each other wrong.

On consensus in science, it’s quite hard to find examples in modern science where the consensus was wrong, from the dangers of tobacco to the ozone layer. Examples quoted usually predate the rise of the scientific method.

Q5.Ok, so what is the principle at work in the current climate change?

A. The physics of the greenhouse effect is quite straightforward. The earth’s heat balance is regulated by certain gases in the atmosphere that trap emerging heat, known as greenhouse gases. Given the sensitivity of the earth’s heat balance to greenhouse gases, and given that we have increased their concentration by 40%, one would expect a gradual increase in trapped heat and temperature. This is exactly what we measure, in many different ways.

Q6. Any good news?

A: There’a a Nobel prize waiting for anyone who can show that carbon emissions don’t matter i.e. that greenhouse gases created by human activity quietly disappear instead of clogging up the atmosphere (about 50% currently gets absorbed by the oceans, but that is also causing problems and cannot last). Drinks on me if you do prove this.

Update

There is a reference to a really interesting paper in the comments section, thanks Justin! The paper, by Tony Dorlas of the Dublin Institute of Advanced Studies, takes a most unusual and simple approach; in the complex system that is climate, take the one parameter that is varying in a systematic way  (C02), explore from first principles what variation in average temperature this parameter could lead to, and compare the results to the measured warming. The result is pretty thought-provoking, see here

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Where is the global warming?

A few days ago, the letter below was published in The Irish Times, Ireland’s most respected newspaper:

Sir, – I’ll believe in global warming when I don’t have to turn on my central heating in mid-June. – Yours, etc,

PETER STAPLETON,

Drumshanbo,

Co Leitrim.

As the short statement contains three common misunderstandings, I thought it worthwhile to respond. My response is published in The Irish Times today :

Sir, – Peter Stapleton writes “I’ll believe in global warming when I don’t have to turn on my central heating in mid-June” (June 16th). This short statement contains three classic errors:

1. Weather is not climate. Mr Stapleton has confused a wet summer in Ireland with longterm trends in global climate.

2. There is now a great deal of evidence pointing towards a gradual increase in the average surface temperature of the earth and its oceans, an increase that is strongly linked to carbon emissions. Recent data from MET Éireann show a warming in Ireland in line with this global trend.

3. Climate change is not a question of belief, it is a question of science. The overwhelming consensus among climate scientists is that global warming has the potential to affect the lives of many millions of people, from widespread flooding in some countries to permanent drought in others.

Sadly, one suspects Mr Stapleton’s misapprehensions are shared by a great many political leaders worldwide. – Yours, etc,

CORMAC O’RAIFEARTAIGH,

Lecturer in Physics,

Waterford Institute of Technology.


All in all, I think the two letters sum up the challenges of communicating climate science. Could it be that mankind will one day face devastating cimate change, all because we couldn’t distinguish between weather and climate?

Flooding in Bangladesh: soon to be permanent?

Drought in Africa: more frequent and severe?

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Tyndall conference in Ireland

This weekend, I caught the last day of a climate conference honouring the memory of the great Irish scientist John Tyndall. Born in County Carlow, Tyndall became a key member of the Royal Society around the time of Charles Darwin. He studied under Robert Bunsen in Germany and did much to promote the idea of experimentation in science. Among his many contributions are the discovery of the Tyndall effect (an explanation for the colour of the sky in terms of the scattering of light) and pioneering works in optics.

Tyndall’s most important contribution was his experimental demonstration of the greenhouse effect. He was the first to show that certain gases – notably carbon dioxide and water vapour – absorb radiation of infra-red wavelength, thus trapping heat reflected from the earth. This discovery forms the bedrock of the modern climate science. Today’s phenomenon of global warming (measured as an increase in global temperature, glacier-melt and sea level rise over the last few decades) has been attributed to an increased concentration of greenhouse gases in the atmosphere caused by the burning of fossil fuels.


The 2011 Tyndall climate conference was sponsored by the EPA and the Royal Irish Academy

The conference celebrated the 150th anniversary of the publication of Tyndall’s landmark paper On the Absorption and Radiation of Heat by Gases and Vapours and took place in Dublin castle, a superb venue in the heart of Dublin’s vibrant city center (and the seat of British rule in Ireland only a century ago). Day one was an overview of Tyndall’s life and work, with a keynote lecture by eminent climatologist Richard Sommerville. The next two days featured slightly more technical talks on climate science. You can find the conference program and book of abstracts here.

I caught several excellent talks on Friday, including a talk on climate sensitivity and feedback mechanisms by John Mitchell of the UK Hadley Centre, and a talk on tipping points and their predictability by Peter Ditlevensen of the Center for Ice and Climate at the Niels Bohr Institute in Copenhagen. Another talk, by George Moore of the University of Toronto, suggested that we may already have passed such a tipping point. The lecture  ’20 years of IPCC projections’ by Ulrich Cubasch of the Free University of Berlin, demonstrated how well IPCC projections have stood the test of time. This is a point often overlooked in discussions of climate science in the media. The public are wary of theoretical models, and climate scientists sometimes forget to point out that we have had twenty years to test predictions – so far, the projections have turned out to be all too accurate.

Possibly the most advanced talk of the day was by Professor Ray Bates of the Meteorology and Climate Centre at University College Dublin, a former professor of meteorology at the Neils Bohr Institute. In his talk, Ray presented a new global climate model, contrasting it with the recent model of Dick Lindzen. The Lindzen model is quite controversial as it suggests that conventional climate models overestimate the contribution of an enhanced greenhouse effect on climate. In good scientific fashion, Ray outlined the basic physics underpinning the two models, steering clear of polemics and concentrating on the science. You can Ray’s paper on his, and other, models here .

All in all, a great conference, I was sorry to miss the first two days. One of the aspects the increased teaching workload in the Institute of Technology sector is that there is almost no time left over for conferences – someone’s idea of increased productivity.

Update

Richard Sommerville did a very nice interview on the Pat Kenny show, a flagship radio show on RTE radio 1. Pat raised almost every point favoured by climate skeptics, while Richard provided clear and cogent answers to each. Well worth a listen, you can download a podcast here.

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