“Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level.”
This is how Barry O’Dwyer, Senior Researcher at UCC’s Environmental Research Unit, began his ‘Preparing for the Inevitable’ talk at Wexford Library last Tuesday. Presented in association with Future-Proof Wexford the focus of the evening was about the changes already being wrought by climate change and how we must act to both lessen and cope with these changes.
“There is certainty at the 95% confidence level that this warming is caused primarily by human interventions in the Earth’s coupled ocean-atmosphere system,” said O’Dwyer. “Globally all the trends point to temperatures rising at an unprecedented rate.”
April 2016 has been recorded as the warmest on record. This warming is the reason the World is experiencing rising sea levels, changing patterns of precipitation (rain/snow), increased storminess and more frequent periods of drought.
Ireland is no exception to these effects. In general our weather is now warmer, wetter and, as we saw last Winter, more stormy. Indeed last Winter’s storms were the worst, in terms of intensity and frequency, that we experienced in 143 years.
Globally sea levels have risen by close to 200mm since 1900. There is still some uncertainty as to how the continuing increase in emissions will impact on sea level rises. Estimates vary from 0.5m to 0.8m.
Climate change is bringing real and visible changes to Ireland, some gradual, others more unexpected and extreme. Examples:
Our growing season has changed;
The tillage, veg and fruit we grow will alter as changing conditions affect yields (how long before Wexford’s first commercial vineyard!)
High water flows are increasing;
Increased incidence of water quality being negatively affected;
Soft coasts are seeing more intense erosion;
Sea fish (eg mackerel) stocks have been negatively affected.
Projections for future global climate change are based on expected, or possible, future levels of greenhouse gas emissions, the response of the climate system to these, and natural influences on climate such as volcanic activity and changes in oceanic circulation patterns.
Future projections for global temperature are difficult to call. As Barry O’Dwyer put it “when it comes to global tipping points, all bets are off”. A low-emissions scenario could see a rise on 1990 levels of around 1.5°C. With no curb in emissions the rise could be 4-5°C. In the latter case the effects globally would be devastating: big sea level rises and major flooding, heatwaves, water and food shortages, melting glaciers, acidification of the seas, marine ecosystems destroyed, etc.
As things stand now, Ireland is looking at an increase in periods of drought and heavy precipitation events. With drought we will experience water shortages and water quality issues. The southeast can expect a 20% drop in Summer precipitation but much heavier precipitation when the clouds do open. The landscape and biodiversity will be negatively impacted – the agricultural sector will find itself adapting to cope with warmer Summers and longer, drier periods.
The flip side is that we can expect increased flood risk with more and more areas affected and more incidences of “bridge scour”, the process by which the structure of bridges is undermined. Storms, at least as intense as those of last Winter, will become a more common occurrence. The impact of sea level rises and storms will be seen initially on the southern coast while soft coastlines will be at increased risk. This will also have implications for ports, harbours and other coastal infrastructure.
On a more serious level there is a possibility that Ireland, and Europe, could lose the warming effect of the gulf stream giving us much colder Winters.
The two principle ways of dealing with climate change are mitigation (reduce emissions and you reduce the main cause of climate change) and adaptation (coping and preparing for the challenges ahead).
At the COP21 talks in Paris last year World leaders set a max policy target of 2°C warming on 1990 global temperatures. Projections using multiple global climate models give estimates of likely temperature rises for different levels of greenhouse gas emissions. These “Representative Concentration Pathways” give four likely outcomes varying from a low emissions rise of up to 2°C to a high emissions 4.5°C. Emissions would need to peak in the next five years if we are to have any chance of staying below a 2°C rise. We would also need to see net removal of CO2 from the atmosphere in the second half of this century to stay within target.
Is the political will there to collectively make this happen? Suffice to say that when it comes to dealing with the effects of climate change we are now looking as much at adaptation as we are at mitigation. Barry O’Dwyer says that adaptation is now considered an essential part of planning and socio-economic development. It involves learning by doing and constantly reviewing strategies and policies.
At a national and local level adaptive management might see us widening drains to increase capacity, installing one way valves, raising floor levels, using flood resilient materials, using sustainable means to slow down fast-flowing and swollen rivers, and, in some cases, relocating families.
While adaptive management is key to any policy what else can be done in Ireland to deal with the threats presented by climate change?
Ensure climate change is integrated into socio-economic planning at local and national level;
Raise public awareness and understanding both in the community and at public representative level;
Ensure equity and fairness play a part in any plans;
Continue to develop the evidence base – hard facts are hard to deny;
Accept that climate change is no longer just a notion, something that might happen. It is happening now and its effects will only become greater.
And the mention of “snakes” in the title? It would appear that there is a small but active snake population resident around the Dodder River in Dublin. These are snakes that were bought as pets but which subsequently escaped, or were released into the great outdoors. The warmer year-round temperatures means that they can now survive in the open. They are having a negative impact on the biodiversity around the river.