Extreme heat slammed a climate similar to ours. So, could it happen here?

23 July 2021

Mia Jacobson was used to heat. Growing up in the tropical climate of Hawaii, they were accustomed to the discomfort summer can bring.

But when the recent heat dome that struck their now-home of Portland, Oregon, each day became a matter of survival.

“I got this fight or flight response from it. Like I just need to do whatever I can to keep my brain from frying,” Mia said.  

The oppressive heat wasn’t confined to just Oregon. The normally tepid Pacific Northwest broiled in late June. Portland hit of a high of 46.6 C, while Seattle’s thermometer climbed to 42 C. Lytton, a small town in British Colombia, Canada set all-time national heat record of 49.6 C. Just days afterwards, it burnt to the ground.

Walking outside and seeing the barren streets as temperatures soared was a desolate experience, according to Portland resident Maddy Miller.  

She was lucky, because she and her housemates had air conditioning in the living room. In the beginning, gathering all together in one space was “fun for a little bit”, she said.

“But then you realise you’re all just suffering in the heat.”

Leaving the one air-conditioned space was like, “stepping into a hell dimension”, she added.

Many homes in Portland and throughout the Pacific Northwest don’t have cooling units. Friends of Maddy’s without air conditioning were left to their own creative devices to stay cool. They’d put clothes in the freezer or spray water at a fan.

Outside the confines of individual homes, public infrastructure that never experienced such heat started to fail. Streets started to buckle. Light rail and street car service was suspended in Portland as power cables melted.

Parts of the region had to ration how much energy they were using to stay cool. Nataša Kvesic was in Eastern Washington during the heatwave, and remembers having to restrict how much they were using because, “our grid couldn’t handle it.”

Cities opened up cooling centres. Hundreds died, as these temperatures exacerbated the vulnerabilities of many. High overnight temperatures placed further pressure on population. The extreme weather affected biodiversity as well, as thousands of sea creatures cooked to death.

The heat, in short, created “a mass casualty event“.

But could this happen in Ireland?

According to Interngovernmental Panel on Climate Change (IPCC) scientist Professor John Sweeney, both Ireland and the Pacific Northwest are experiencing heatwave conditions.

A jet stream looping south over the Atlantic is “giving us exceptionally warm, dry conditions”, he said.

However, heatwave conditions will not get to the same extreme like they did in the Pacific Northwest, Prof Sweeney added.  

Both Ireland and the Pacific Northwest are climatically similar. They’re both located on the north-western side of a major ocean, which results in mild, cloudy, and wet winters with somewhat drier and warmer summers.

But there is a ‘fundamental difference’ between the two, according to Maynooth University Climate Scientist Professor Peter Thorne.

“It’s really the ocean and the seas that moderate the climate,” Prof Thorne said.

As an island surrounded by water, Ireland’s weather is more stable with a maritime climate. This is a crucial difference to the continental climate in the Pacific Northwest, which has a significant land mass to the east.

Both Prof Sweeney and Prof Thorne agree that it is unlikely Ireland will hit the extreme temperatures the Pacific Northwest experienced.

Due to the stability of the Atlantic ocean and minimal mountain ranges, Ireland is more protected from the extremes. Though it is possible that in the coming years the high temperature record of 33.3˚C recorded at Kilkenny Castle in 1887 could be challenged.

As the climate shifts to an increasing warming of the atmosphere and an ability to hold more water vapor, “it means that we’re likely to have more of these extremes in the future” added Prof Sweeney.

Additionally, “there are two things we know for sure with climate change” Prof Thorne explained. “That extreme rainfall events are being made more likely, and that extreme heat events would be made more likely.”

Human-caused warming

The most recent heatwave in the Pacific Northwest was ‘virtually impossible’ without human-caused climate change, an international team of climate researchers found.

The same group of researchers similarly found that human contribution altered the likelihood and intensity during the 2019 heatwave in Europe. The year prior saw a weather event in which man-made climate change doubled the chances of the ‘unprecedented heatwave.’

“Across a huge range of published studies, say for the last decade, almost every single heat wave has been linked to some extent of human existence,” Prof Thorne noted.

But anthropogenic climate changes affect more than just rising temperatures and intense heat.

Prof Sweeney notes that the warming of the Arctic region and melting of sea ice will weaken the jet stream, “giving rise to more of these undulations and extremes.”

Thus, there may be links between increasing extremes of heatwaves and the vulnerability of the jet stream to become more variable, and could affect precipitation levels in other parts of the world.

Prof Sweeney also expects wetter winters and drier summers as the jet stream moves north. This would result in issues that vary across the country. In the West, you can expect increased flooding in the winter, while in the East, there may be water supply issues during the summer.

But the influence of a changing climate doesn’t stop there.

“If we’re going to have drier and lower flow conditions in our rivers, that means that they’re going to be more susceptible to pollutants.” Prof Sweeney added.

So, an extreme heat event in Ireland is unlikely “even under the worst-case scenario, even in 2100” according to Prof Thorne.

But due to rising temperatures and related effects, “people will undoubtedly feel uncomfortable here,” he said.

Adapting to heat

To combat the impending discomfort, Maynooth University Adaptation Scientist Dr Stephen Flood outlines both adaptation and mitigation measures that are needed, stressing that Ireland can, “increase our resilience and needs to take action to do so.”  

It’s a case of preparing and “Ireland being ambitious in terms of its adaptation actions”, according to Dr Flood.

With national, regional offices and local authorities all with plans to adapt to climate concerns, the critical component is the implementation.

The trends suggest increasing extremes lead to more droughts, so both measures to mitigate and adapt are necessary.

“If we were to completely turn the tap off of greenhouse gas emissions today, there’s still that energy in the system,” said Dr Flood.

“We will need to build our societies to adapt as well.”

Though when it comes to heat, “everything is interconnected and that it’s not just a one-off event”, Climate Action Coordinator for Dublin City Council Dr Sabrina Dekker said.

In working with Dublin City Council, Dr Dekker describes her approach with nature-based solutions. Previously, she said the Council had worked to “tame nature versus working with nature and respecting nature.”

She’s now focused on greening the city using nature-based solutions.

Dr Flood echoed the need to ‘green’ cities. Shade cultivated from trees helps cool urban centres that are more susceptible to the effects of heat due to concrete and vulnerable populations. In agricultural areas, adaptation measures involve using heat-resistant, low water use crops and grasses.

Though these adaptation measures are critical to address a changing climate, some challenges are bigger than others.

Dr Dekker also argued that the biggest adaptation challenge Ireland is facing is supply, security and an ‘outdated drainage network’.

The rainy climate can create a ‘false sense of security,” she added.

One action Dr Flood is taking to combat this potential threat is using a 250-year historic drought catalogue.

“We can basically stress test the system and see how the system would deal with some of these major historical droughts. And in that way, we can see how the system could deal with future droughts,” he said.

Taking action

These experts expressed that sustained action will be necessary to address extreme heat effects of the climate crisis at both the collective and individual level.

Dr Dekker’s role involves examining how local governments can engage with communities and citizens.  Through her work, she believes that “there are little things that you can do every day to make a difference.”

One of these things is to take agency over the food we consume, as water, soil and food are three things with a big impact on the climate. She recommends slowing down, appreciating nature and the time it takes to grow something.

That individual agency must be balanced with collective action as well. Dr Flood and Prof Sweeney both argue that we need to be “ambitious” in adaptation measures and actions.

“All of this really reinforces the need for Ireland to play its part on the international stage,” Prof Sweeney urged.

While highlighting impending global risks on the horizon, Dr Flood stressed, “I think we need to fundamentally change our relationship with the planet and what we’re doing. It’s not sustainable on many levels.”

Though Ireland may not face genocidal temperatures like the Pacific Northwest, there are still concerns for impending hot days.

If extreme heat did ever hit Ireland, the aforementioned Portland resident Mia Jacobson had some advice for its inhabitants.

They said it was crucial for everyone to “take it seriously, and do whatever you can for yourself and for your neighbours” in order to make it to the other side.

By Sam Starkey