5 Questions on Climate Change

Professor John Sodeau, UCC. Photo: Emmet Curtin.
26 Aug 2016

Professor John Sodeau discusses climate change and what Ireland can do to play its part in the fight against the phenomenon termed global warming.

97% of climate scientists believe that we humans have a direct influence on our climate and are responsible for the phenomenon termed global warming. After many years of dithering, politicians have recognised that something needs to be done, and done quickly, to avoid globally catastrophic events such as drought, extreme weather events, desertification, food shortages and mass-scale emigrations from the most likely affected countries such as Bangladesh. But the general public still are skeptical, in part due to some politicians who hold strident opinions not based on scientific facts.

Fortunately, a fight-back by people who are knowledgeable has begun to happen. For example, a striking temperature spiral graphic was shown at the recent opening ceremony of the Rio Olympic Games to show how close we are to now breaching the 1.5 oC barrier beyond which our planet might not be able to environmentally recover. And so here is my own small contribution to the debate.

Q. Is a greenhouse a good way of explaining to the public why climate change is happening?

A. It is good for explaining the natural (or baseline) Greenhouse Effect that allows planet Earth to be habitable. As we all know seedlings, flowers and vegetables thrive in the glass structures often found in our gardens. And we thrive in a world that has an atmosphere like ours. Ultraviolet and visible light from the Sun gets through to the surface turning into heat, which then tries to escape the planet. But much of it is effectively trapped by an atmosphere that contains water vapour, carbon dioxide and ozone.

However, there is a better analogy for the enhanced Greenhouse Effect that we have experienced since the Industrial Revolution began in about 1830. That is to think of our atmosphere as a woolen shawl with holes in it. Then, if we increase the thickness of the wool (the carbon dioxide content) or fill in the holes (with other “Greenhouse” materials like methane or nitrous oxide or soot-like particles), we get hotter. And that is the global warming experience we read about most days of the week now, although that is just one of the changes in our climate system that we are currently experiencing.

Q. Who is to blame for global warming?

A. We all are because we all want three cars, four TVs and five laptops/i-Pads/mobile phones in every household (go on count them!) Using all that energy in a fossil fuel based economy leads to carbon dioxide production. But if we want to identify some particular whipping boys besides prevaricating politicians and decision makers around the world then one of them would be me for keeping quiet for too long about the dangers we face from climate change. The reason I have held back, but it’s not a good enough defence really, is that scientists tend to use safe, precise, remote vocabulary that has any emotional resonance stripped away. And so we often lose the ability to communicate effectively with the general public. That has meant demagogues and village idiots have been allowed to occupy (until recently) an empty playing field in order to seize the climate change agenda for their own purposes.

Q. What current scientific data is available about climate change that worries you the most?

A. There are three, likely connected, sets of measurements that have worried me from observations made over the last couple of years. The first is from an Observatory sited in a remote location in Hawaii called Mauna Loa. Measurements of carbon dioxide levels in the atmosphere have been taken there since 1958. Between 1960 and the mid-seventies the increase was about a 1 ppmv (parts per million by volume) increase on average per year. This value increased to an average of about 1.5 ppmv between 1975 and 1995 and again increased after that, by about 2015, to a level of 2 ppmv. But between 2015 and 2016 the figure doubled to 4 ppmv. That worries me.

Also there are now measurements from NASA that show the 10 warmest years in the 134-year record that is available (since 1884) have all occurred since 2000, with the exception of 1998. And the year 2015 ranks as the warmest on record!

And then there are the record lows in Arctic sea-ice that have been observed this past year.

Q. Is it too late for us to prevent the environmental problems (such as extreme weather events, drought, food insecurity and mass migrations) predicted to accompany climate change over the next 30 years?

A. It might be.

Q. What can Ireland do to play its part in the fight against global warming?

A. Individuals can always do more by reducing their carbon footprint in a fossil fuel-based economy. But every country can always do more by continually assessing their policies about agriculture, transportation and generation of energy that underpin their respective economies. However, we should be wary of making political deals that put the strength of the national economy first and foremost. No matter what the calculations about “Greenhouse” gas reductions are and the relative fairness to national economies, we should all aim to reduce our footprints to zero. Otherwise triumphant politicians may simply win Pyrrhic victories because the various national economies will not be there if we are under water or live in a desert or on an island that has no fields or wildlife or agriculture. Just trees.

John Sodeau is an atmospheric scientist who has who has performed research in the area since the late 1970s. When he worked in the University of California at Irvine, UCI, he had coffee most mornings with Sherry Rowland and Mario Molina who were soon to win a Noble Prize in Chemistry for making the connection between chlorofluorocarbons (CFCs) and stratospheric ozone depletion. He came to UCC in 1998 where he set up the Centre for Research into Atmospheric Chemistry, CRACLab, which is part of the Chemistry Department and the ERI, alongside John Wenger. He had an epiphany about two years ago when he realised how little scientific knowledge breakfast-time radio presenters possessed and decided to become much more active in communicating with the public about the problems and challenges we face with air pollution and global warming. Check out the crac.ucc.ie website for much more information on air pollution and climate change.