John Sodeau

Air pollution and climate change expert and researcher.

Read this first

I don’t have the words…..

In the book, “Through the Looking Glass and what Alice found there” by Lewis Carroll, the White Queen admits: “Why, sometimes I’ve believed as many as six impossible things before breakfast.” I wonder what she would have thought about climate change? Would she be a believer or a denier?


On a recent RTE Claire Byrne Live programme a question was posed to a panel of 1000 people: do you believe that climate change will pose a serious threat to the world in your lifetime? 57% said yes but over a third said no with about 10% not knowing what they thought. In the same week, another survey was published but this time involving 8000 people from eight countries – the United States, China, India, Britain, Australia, Brazil, South Africa and Germany. It found that 84% of its sample believed climate change to be a “global catastrophic risk". That means the deniers represented less than half of

Continue reading →

Past its Prime Time

in a recent contribution to Prime Time the journalist, David McCullagh, asked the question: with around a million diesel cars in Ireland, how do we battle the health risks of diesel exhaust emissions? Good question but the
answers given were narrow and outdated and missed out on key information that the public needs to hear more often.


As they said on the programme, more than 1000 premature deaths from air pollution likely occur in Ireland each year. Many of these can be attributed to emissions from petrol and diesel-powered road transport. (Many also come from brake/tyre wear, solid fuel burning and agriculture). In London about 9500 extra premature deaths are estimated per year with a bit less than half due to the small, soot-like, solid particles that we call Particulate Matter (PM). More than half of them though are due to another important air pollutant coming from road

Continue reading →

Bin Diesel?

I am Spartacus. I own up to owning a diesel car. I should know better with my job but I’m human and I’m waiting for mid-level electric cars like Tesla’s to be readily available to us in Ireland. Increasing diesel pump prices and car taxes would also help me to move along my inevitable pathway. Not being able to get insurance on a diesel car would also help. None of this may be relevant soon because none of us maybe be able to even buy a petrol or diesel car by 2030……


There have been a number of recent pre-budget leaks about an up to 18 cent increase in diesel pump prices. Is a price increase on diesel necessary? Why?

There are compelling health reasons why diesel prices should increase at pumps. Not least the World Health Organization’s (WHO) recent classification of air pollution in general and diesel specifically (but not petrol) as Group 1 carcinogens, that is like cigarette

Continue reading →

Rae of Sunshine

I’ve just come back from Sunny California and in the last three weeks I’ve heard Donald Trump time and again calling for much more oil drilling in the USA because he says climate change does not exist. Then one of my research students (who is a Kerryman through and through) sent me a link from last week’s Irish Examiner giving a platform to the increasingly bizarre views of Danny Healy Rae about the same topic. So the headline was: To say Man is changing the weather is nonsensical. My headline would be: To say Dan knows anything about climate change is nonsensical.


His fundamental point is that natural phenomena like volcanoes, caused by Superior Influences lead to climate change. And we have nothing to do with it all at all, at all.

The problem is that he, like many other politicians such as Trump, have little to no understanding of science. Now people like me bear some of the

Continue reading →

Green with ENVA?

I saw the Irish EPA taking part in some real car crash TV for their organization last week on RTE’s PrimeTime programme. It involved numerous public complaints that had been made about the odours and likely health risks associated with the ENVA oil waste facility in Portlaoise. And, of course, who was to blame for the problems.


A “foul and pestilential congregation of vapours”, as Hamlet once internalized about, has gathered over Portlaoise since about 2000. Numerous complaints have been made by people living and working there over many years about bad smells and headaches and sickness. And so by now the media, the Seanad and of course the EPA are well aware of the town’s periodic problems with air quality. The culprit responsible has even been identified, caught and fined by the EPA. So why has every person that I’ve discussed the RTE programme with criticized the EPA rather than

Continue reading →

The Why, How and Where of Irish Air Pollution

“This most excellent canopy, the air, this brave o'erhanging firmament, this majestical roof fretted with golden fire, why, it appears no other thing to me than a foul and pestilential congregation of vapours. What a piece of work is a man!”

Hamlet Act 2, Scene 2. William Shakespeare


Why do particulates matter?

We have known for many years that carcinogenic chemicals and much smaller particulate matter (PM) than soot are produced by the combustion of fossil fuels. The small solids, termed PM2.5, are invisible to the naked eye but can kill with long-term exposures.

PM is a complex mixture of extremely small particles and liquid droplets that is made up by a number of chemical components including acids (like sulfuric and nitric), organic compounds (some carcinogenic), elemental carbon (soot) and metals (like lead). So the materials involved are mainly quite toxic. The composition

Continue reading →

Air emissions from farming might kill off coal and diesel burning in Ireland

When three planets align in our solar system it is called a syzygy. When three important air pollution issues align in one week then it is a synergy that might have far-reaching consequences for Irish air quality.


Three stories about air pollution have made the news in the last week. They might at first sight appear to be unrelated but, in our atmosphere, they are actually closely connected.

The first news article resulted from a publication in Nature showing that more than 3 million people a year are killed prematurely by outdoor air pollution, that is more than Malaria and HIV/AIDS combined. Atmospheric scientists were unsurprised at this because it is well known that burning coal, wood and peat as fuels in open fires at home releases small solid particles (known generally as soot or black carbon) that can enter our lungs leading to severe health effects on asthmatics and others

Continue reading →

Will the drop in world milk prices help to save the planet?

On 10th September the Irish Government agreed to take in 4000 refugees many of whom are leaving their homes as a result of the Syrian conflict. This number will be dwarfed by the possible level of environmental refugees predicted to be on the move later in the century because of global warming. That is, 150 million or more! How would Ireland cope with its share of that number?

Milking cow.jpg

The release of the Green House Gases (GHG), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) into the environment leads to global warming. There is no argument about this fact. The effect for CO2 was predicted as far back as 1896.

The presence of GHG in our atmosphere causes an effect on planet Earth that is just like the one caused by the panes of glass we use to build our garden greenhouses to help grow delicate plants. That is they let the sun’s visible light through to hit the ground or the

Continue reading →

Playing and ploughing with cold fire

Kfm in Kildare phoned me the other day to talk about the warning notices that Irish Water had just issued many households with in the Dublin area regarding lead piping. It got me thinking because at the same time a potentially related environmental problem was unfolding at the Killarney Lakes where I was on holiday.


In mid-August the public was warned not to drink from, fish or paddle in Lough Leane, which is the biggest of the Killarney lakes, after algal scum made up of blue-green cyanobacteria and other phytoplankton was observed there at a number of locations. The calm, warm weather conditions were suggested to be a reason for the problem but the root cause is most likely to be related to a build-up of phosphate nutrients from natural sources, detergents, farm effluent and sewage. They are, after all, the same reasons for the same problems seen there in the 1980s and the 1990s.

Continue reading →

Here comes the Sun

I was asked recently by the European Photochemistry Association to write an article about my career experiences in the subject of Photochemistry. Many others also contributed with the hope being to attract a whole new generation into the field. All I can say is that I have had a blast.

here comes the sun.jpg

An article with a title like the above will go one of two ways: the “solar energy materials” route or the “our atmosphere” route. (It could, of course, go by both if it is about “understanding photosynthesis”). Photochemistry obviously is the foundation for all three pathways but where the road goes very much depends on where the student starts walking. My lifelong interest in “Photochemistry and Photophysics” began while still an undergraduate at the University of Southampton (I won’t embarrass the person who sparked it all for me!) But my real journey started when, as a Postdoctoral Fellow at the

Continue reading →