Professor John Sweeney:

Good morning Deputies and Senators. I will kick off with a brief introduction to issues where I think there is a very strong linkage between the Paris agreement and issues which are relevant to the Department of Foreign Affairs and Trade. I suppose this is our target audience when dealing with these matters. People in the developing countries have a particularly difficult way of life at the moment. Last September, I travelled to Zambia as part of a group from Maynooth. Maynooth University runs a masters programme with some African universities. We were graduating 26 students from Maynooth University, who were all based in Zambia and Malawi. As part of that, I visited some of the people concerned. We were dealing with people at the grassroots level in terms of poverty. They are some of the poorest people in the world. I went there to hear their particular issues which I think are quite relevant. A slide shows their community hall and church where we listened to what they had to say, both the older and younger people. The men and the women had very different issues. When one is dealing with issues of environment and climate, it is important to hear some of the older voices in the community because they will have long memories about extreme events and whether things have changed substantially.

Another slide shows an old man in whom I was especially interested. He told me the hardship he had now begun to experience was because of a fundamental change in the reliability of the rainfall. He said that their seeds withered because the rains had not arrived on time and that their crops were dying in the field because the rains were retreating earlier than had been his experience over many years. Therefore, acute hardships were being felt. Although he did not directly say this to me, the unwritten question was, why is this happening? Who is responsible for these changes? The scientific answer to that would be that it is largely us, in the developed world, who are responsible for what he is experiencing.

I will show the committee two slides that epitomise the problems that are now developing in many part of Africa as a result of climate change. The first slide shows the famous Victoria Falls where the mighty Zambezi tumbles over the escarpment and flows down into Lake Kariba, which is the largest man-made lake in the world. It generates 90% or more of the electricity supply for the country of Zambia and a substantial supply for other countries as well. Members will be able to see quite clearly the problem beginning to emerge. The lack of reliable rainfall and an absence of rainfall mean the rains no longer feed the falls and, in turn, the falls no longer feed the hydropower station on which so much of that country depends. As a consequence, there are all kinds of knock-on effects for the economies and societies in that poorest part of the world.

People can live without heat in tropical Africa but one still needs to cook food and if there is no electricity, then one has to use charcoal. Deforestation is taking place as a consequence and is now emerging as a major problem. One can see that urban dwellers are starting to move large amounts of wood into the cities. Even the poor people who walk on average 11 km a day to collect firewood in that part of the world now find it increasingly difficult to source wood. In the cities, there are 12 hour power cuts, resulting in disinvestment which, in turn, is producing high unemployment and thus hardship in the cities concerned. The impacts of climate change, although we think of them as something alien to us, are really profound in many parts of the developing world. Irish Aid is active in these countries in terms of trying to foster sustainable development.

We know from the climate science conducted by the Intergovernmental Panel on Climate Change, IPCC, that we are on an upward trajectory. In each of the past three decades, the earth has been warmer than in any of the preceding decades since 1850, when reliable records began. We know that for the past 30 years, we have been privileged to live in the warmest 30-year period of the past millennium and a half on this planet. Things have changed, and they are changing quite radically.

It is not simply the developing world that is affected by this situation. There are strong connections back to us here in Ireland. We know that the flooding that we have experienced here in the past few weeks has had a component in it which has intensified its magnitude.

That has rendered that kind of an event likely to occur more frequently as a result of climate change. It is a connection that is universal for all of Ireland.

We will see changes in our agricultural viability and the kinds of pests and diseases that we must cope with in agriculture. We will also see changes in the infrastructural protection that we need in our towns and cities. As with all environmental hazards, we will see them affecting those who are least able to bear them. It is one of the features of environmental hazards of all kinds that they tend to affect the poorer people in society and those who do not have the wherewithal to escape and protect themselves. For example, our small farmers will be particularly at risk. We know the changes will entail considerable costs for them. We have seen a hint of that in the fodder crises from a few years ago and we will see that kind of event more commonly in future.

We know last year was the warmest year globally on record, and before that it was 2014. That was partly contributed to by a major El Niño event but it was also partly brought about by the ongoing loading of the atmosphere by greenhouse gases. We know from our own hard experience in Ireland the impact of extremely wet months such as last December, the wettest December since we started reliable measurements in the 1940s or so. It has been an exceptional past few months in Ireland.

Anywhere in Ireland today is a half degree Celsius warmer than it was 30 years ago. Ireland is warming at the same rate as the rest of the world, on average, and as a mid-latitude country that is unsurprising. Every month of the year is roughly a half degree Celsius warmer than it was 30 years ago. Climate change is affecting us and it is under way in Ireland. Our models suggest we will undergo another warming of a half degree Celsius in the next 20 to 25 years. The trend is quite clear and what is happening in the rest of the world is having an impact on us in Ireland in terms of temperature. The models suggest there will be a further and perhaps more severe impact on Ireland in terms of rainfall. The red areas in the map distributed to members indicate areas where in winter we expect substantial increases in rainfall with all the consequent impacts for flooding. We expect drier summers with all the consequent impacts on water supplies for towns, cities and agriculture.

It is quite clear from the fifth assessment report, which the Irish Government has signed up to - as it has with all the Intergovernmental Panel on Climate Change, IPCC, reports since 1990 - that there is a very strong link between the cumulative amount of carbon we put into the atmosphere and the climate change it induces. In particular, the Paris agreement, which we are discussing today, has as a focus the need to avoid taking the temperature change to levels at which we enter the unknown in climate science, specifically what is unknown about what will happen in Greenland, Antarctica and the gulf stream.

There is an issue I will address before we move on. There is a strong relationship that came from the last IPCC report and although it was alluded to in Paris, it did not form the centrepiece of the negotiations. One suspects that was for political reasons. There is a straight line between how much we have historically put into the atmosphere and how much warming we have experienced. One can see that over the past century or so, we have put in approximately 500,000 million tonnes of carbon and the relationship with temperature is very straightforward, with under a degree Celsius of warming. We can base future carbon emission predictions on that. Taking it forward, if we want to avoid warming of 2° Celsius, we have a certain carbon budget and once we exceed it, we will irrevocably enter dangerous climate change territory. That entry will occur when we exceed an emission of approximately just under 800 billion tonnes of carbon.

That is what we have to work with globally and once we go beyond that as a planet, we will have warming of 2° Celsius come what may. Currently we have emitted 545,000 million tonnes of that 790,000 million tonnes of carbon. What we have left to divvy up among the global community is 245 billion tonnes. That may not sound like much carbon but we are currently putting into the atmosphere approximately 11 billion tonnes every year, meaning we have 24, 25 or 30 years at the most to get that carbon emission sorted out. That is why the IPCC is quite adamant in its conclusion that there are only two decades left before the window closes and we can avoid a dangerous climate change scenario. That will of course impact not just the developing world but also Ireland. That is why it is important that we enter the territory of decarbonisation as soon as we can, not just for the sake of the developing world. I have indicated that it is already experiencing acute stress from climate change but we must also think of our own citizens, who will also in the medium and long term have to face the consequences of quite serious change in climate.