Regional projections for Ireland and what they mean for our gardens
There isn’t any doubt that Ireland’s climate has already changed. Irish climate observations go back to the 1700s, and they tell us that people living a century ago would not have recognised our “normal” as such.
Human activities are estimated to have caused approximately 1°C of global warming above pre-industrial levels, with a likely range of 0.8°C to 1.2°C, and Ireland’s temperature increase over this period is in line with global trends. 2022 was Ireland’s hottest year on record and followed in the wake of 2021, the eleventh consecutive year with temperatures above normal. Now, June 2023 has been recorded as the hottest June on record. Climate change has already arrived.
What’s more, neither we nor the rest of the world are near our targets for keeping global warming to no more than 1.5°C above pre-industrial levels. In fact, Ireland’s per capita emissions, at 3.98 tonnes of carbon dioxide, methane, nitrous oxide, and other fluorinated gases, were the worst in the EU in the second quarter of last year. They are more than France and Spain’s figures combined and almost twice the EU average. So much for little green Ireland.
There is no serious dispute around the facts: the changes we need must encompass every corner of society and be no less than revolutionary in their ambition. But some sectors, such as agriculture – our single biggest contributor of GHG (greenhouse gas) emissions, at 38% – require something akin to a reinvention. Globally, we need a fourth agricultural revolution.
But while our food system is an immense source of carbon emissions, it is also particularly vulnerable to the effects of climate change. Global yields are forecasted to diminish further as droughts, heat stress, floods, severe storms, and an increased prevalence of pests and diseases ravage crops and topsoil. Higher concentrations of carbon dioxide in the atmosphere lower the nutrient content of crops, which will threaten 175 million people with zinc deficiency and 122 million people with protein deficiency by 2050.
I believe the humble gardener will have an important role to play in changing the food system and building a more resilient society. In light of the inadequacy of the top-down approach in bringing about a necessary revolution in our food system, I fear that a bottom-up approach might be our last resort – at least in the interim – to secure healthy diets for people, provide vital habitat, and ignite a movement towards an alternative food system and food culture.
Such ambitions might seem daunting enough without the prospect of climate change. Large-scale agriculture is not the only area that will be hit badly by climate change. Nothing will escape it. And our gardens must be prepared for adverse weather patterns, shifting seasons, and changing biodiversity, the like of which we’ll never have seen before.
However, thanks to the aforementioned centuries of climate records and the proven and increasing accuracy of climate models, the odds of our gardens’ survival can rely on more than simply battening down the hatches when things get rough. While all future projections are subject to uncertainty, recent climate modelling projections for Ireland are in broad agreement with previous research and are given with fairly high or high confidence.
Gardeners understand the need to expect the unexpected, but it never applied more to our gardens than it will in the future. Regional climate change projections cannot guarantee a specific future, but they can be beacons by which to navigate through it. We should use these indispensable glimpses of the future to inform our garden planning and preparations, to give us the best possible chance of adapting to whatever is on the horizon.
A Hotter Ireland
Rather than cutting emissions by about 7.6% per year since 2020 to meet our Paris Agreement target of keeping the average global temperature below 1.5°C, countries are planning to increase emissions by 2% per year, which may lead to a temperature increase of as much as 4.4°C by the end of the century.
In the nearer term and more specifically to Ireland, the national supercomputer “Kay” projected that average annual temperatures will increase by up to 1.6℃ by the mid-century (2041 – 2060) compared with a baseline period of 1981-2000. Even here on the island, climate change will affect us unevenly, with Eastern Ireland expected to warm by as much as 2.2°C by this period compared with the 80s and 90s.
Heatwaves will increase over the next 40-year period, with the greatest prevalence in the southeast. This poses a risk to those species that may fail to adapt to extended periods of hot weather, which will often be accompanied by droughts.
There may be 68%-78% fewer ice days (maximum temperature below 0°C) and 45%-58% fewer frost days (minimum temperature before 0°C) by mid-century. These are important factors in triggering many phenological phases (e.g. migrations, bud development, egg laying, flowering, fruit development, dormancy, etc.) in plants and animals, and many species’ life cycles will likely be critically disrupted. Pollinators in some parts of the world have already been waking to find that they are either too late or too early for the blooming period, which has obvious implications for food growers reliant on natural pollination.
While this alteration of the seasons is forecasted to result in a longer growing season (12-16% increase), with spring arriving earlier than we are used to, this is not all good news. Perennial fruits, especially apples, pears, and stone fruits, require high numbers of chill hours to produce flowers and fruits. Growers will likely have to replace some fruit trees with varieties that can manage with fewer frost hours and droughty summers. In some cases, it may be necessary to switch to different species of plants, such as figs, peaches, and heat-loving vegetables.
But, as everyone should have figured out by now, climate change amounts to more than rising temperatures. With all this extra heat, there will come more violent storms and other erratic weather patterns, rising sea levels, and the general disruption of natural cycles, relationships, and territories.
More Rain, More Droughts
Hotter air holds more moisture, but interestingly, Ireland is not expected to experience significant changes in annual precipitation by mid-century, except for a 2-17% decrease in the summer (high emissions scenario). We are instead likely to see changes in rainfall patterns and seasonal distribution.
Our summers have already begun to dry, and they will continue to do so. We should be prepared for “dry periods” (defined by the EPA as “5 consecutive days with precipitation less than 1mm”) to increase by 48% by mid-century.
Ireland is relatively poorly prepared for drought, with few big reservoirs. We conserve far less water per person (178 cubic metres) than the EU average (over 1000 cubic metres). In particular, Dublin’s rapid population growth and lagging infrastructure put it in a very precarious position, even in the face of relatively minor droughts. In light of Dublin’s growing needs, there has been a controversial proposal by Irish Water to redirect water from the Shannon. But as Dublin continues to urbanise, such plans invoke unsettling thoughts of aquifer tragedies that should serve as warnings to us, such as the Colorado River and the Aral Sea.
But while our summers and our springs will see less rain, heavy precipitation events will become about 20% more common during autumn and winter. Western Ireland will receive more rain than Eastern Ireland, and rainfall patterns will become less predictable overall.
We can be confident that there will be hosepipe bans to come and times when our gardens flood and become waterlogged. But by learning the techniques of growers in regions with distinct wet and dry seasons, by drawing on other sustainable methods of water management, and by planting flood- and drought-resistant species, we can provide our gardens with a chance to adapt.
More Plentiful Storms
Warmer air circulating in the atmosphere, as well as warming oceans and rising sea levels, will culminate in an increase in very intense storms over the North Atlantic, with these likely to extend southwards to hit land in Ireland more often. Windbreaks, shelterbelts, and other semi-permeable barriers, as well as wind-resistant species, will be invaluable in withstanding high-speed winds in exposed or coastal areas.
But while intense storms are projected to increase in frequency, storms, in general, are expected to become less frequent. Wind speeds should decrease for all seasons, but especially in the summertime.
Shifting Coastlines
The rate of global sea level rise seen between 2006 and 2015 of 3.6mm was 2.5 times the rate seen between the start of the century to 1990. Sea level is expected to continue to rise at this rate, at minimum. This places every major city in Ireland in danger of social, economic, and environmental disasters.
If your garden is located on or near a coastline or tidal waters, you may fall victim to rising sea levels. If there are good reasons to believe that your home or garden is too low-lying or too vulnerable to erosion to survive sea level rise in your lifetime (or the relevant person’s lifetime), you may need to consider moving inland.
For an estimate of the risk to your area of rising sea levels, you can visit Climate Central’s coastal risk screening tool, which will give you an estimate of where is likely to be inundated permanently or annually at different points in the future. The tool is based on peer-reviewed science in leading journals, but should not be regarded as a perfect prediction of the future sea level at your location.
The Disarrangement of Nature
It has been argued that the biodiversity crisis, of which we are in the midst, could pose a greater challenge to us than the climate crisis. After all, while it is entirely within our power to reduce our GHG emissions, once a species is gone, there’s nothing that can be done to bring it back. But the two cannot be tackled in isolation, as climate change is a major driver of biodiversity loss and – perhaps a fact less often acknowledged – healthy ecosystems and the biodiversity of which they are composed absorb half of all anthropogenic GHG emissions. Despite this, we continue to hack away at them, turning major carbon sinks into gigantic carbon sources.
In Ireland, only 2.3% of marine areas and 13.9% of land is protected – just over half the EU average. Formal conservation assessments have not been carried out for all taxonomic groups in Ireland, but for those for which they have, 20% of species are threatened with extinction. While Ireland recently committed to protecting 30% of its land and sea by 2030, we do not know that it will be sufficiently expedient to prevent the extinction of vulnerable species.
It is not an understatement to say that biodiversity underpins our food system, and therefore, human existence. Pollination, carbon capture and storage, pest control, water, air, and soil quality, the mitigation of natural disasters, and climate stability are all services provided by biodiversity; all services our gardens benefit from.
In addition to the loss of natural services that a decline in biodiversity brings, our gardens can expect intruders from overseas, driven by the exigencies of their own changing native habitats. Not all of them will upset the balance seriously, but some are likely to be plague-like in their effect on native plants, and ecosystems that will have already lost much of their biodiversity will be especially vulnerable.
There are clearly self-interested reasons for gardeners to pick up government and industry slack where possible. All gardening involves a combination (in varying ratios) of both providing for nature and taking from it. But while the gains are shorter-lived for gardeners who garden in more exploitative ways that degrade the local ecology, gardeners who act in accordance with nature will reap greater advantages in the long term. A garden that functions as a healthy ecosystem – with healthy populations all the way up the food chain – will be better positioned to survive climate change and the new challenges it brings.
But there is also a higher motivation for us to help nature, which goes beyond the enjoyment we derive from its existence. We Irish gardeners really do have a significant role to play in preserving biodiversity, for humans and nonhumans, for now, and for posterity. The Royal Horticultural Society in the UK has launched a nationwide campaign to fight biodiversity loss through changing gardening practices. They state that there is evidence that even relatively manicured gardens can be important refuges for biodiversity. When you consider the shrunken habitats to which some endangered species cling, it is easy to see the potential of the commonplace garden.
We must aim for a symbiotic relationship with the natural world on which we depend. The fact remains that, in a world where 3% of the land remains ecologically intact, gardeners can play a major role in providing sanctuary to our remaining biodiversity.
The task before us is staggering. Last June, the world lived through the hottest day in as much as 125,000 years. A first in human history, in many ways, it is more monumental than the building of the pyramids, the fall of the Roman Empire, or the French Revolution. But as is often the case in history and our own lives, it is easier to understand the causal significance of actions after they have already been taken.
Climate change doesn’t afford us the luxury of hindsight. But survival will require the advantage of foresight. If we want to be successful gardeners, we must build resilience into our gardens now. That means integrating the best information we have about the future into our garden plans. It means staying adaptable, capable of adjusting to changes as they come, and bouncing back with revised strategies when older ones fail. Cooperation will be central, as we will need each other and other members of our communities to get through the worst times. Perhaps, above all, resilience will mean becoming the ally, not the antagonist, of nature, without which our gardens and we would not exist.
