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How worried should we be about the heatwave?

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Rosie Hewitson
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Scientists explain what to expect in the short and the long term 

After a few storms, the glorious smell of rain on the pavement, and a brief 2-3 day reunion with your duvet, the hot weather is back. Although the hottest day of the year may have been and gone in Britain (Thirty! Five! Point! One! Degrees!), temperatures this weekend are climbing again and the heatwave is back with a vengeance.

You can call me ungrateful all you like, but I would like the sun to go away now. It’s not just the fact it’s urgently, nay, medically necessary for me to eat a minimum of one Twister every day, and my local supermarket was sold out for the whole of last week. It’s not even the fact that my office has a woeful lack of air-con and like all British people I have absolutely no clue how to dress for work when it’s warm outside (and I now live in constant fear of a HR email entitled “SHORTS POLICY”, marked urgent).

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It’s more that with every passing day of oppressively scorching weather I become more and more convinced that we’re living out the beginning scenes of a disaster movie, and all the ice lollies in the world can’t assuage this creeping sense that we have, to use the technical term, Absolutely Fucked Up The Planet. 

Are we, as I fear, hurtling towards a terrible, violent, fiery end within the next forty to fifty years? And if so, what’s the exact timing of the apocalypse (so that I can book the week off work and curate an appropriately sombre hot-weather playlist to listen to as the sea levels rise and we all end up drowning)?

So, first of all, what does this seemingly endless heatwave suggest about climate change? 

Well, according to Alice Larkin, Professor of Climate Science and Energy Policy at the University of Manchester, “we have always experienced heatwaves and natural variations in temperature” so we can’t necessarily attribute this particular heatwave directly to climate change. However, she says, the climate is now 1°C warmer than before the Industrial Revolution, “which means that when we do experience heatwaves they are hotter than they would have been.” 

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Not only is the global temperature hotter in general, but extended periods of hot weather will continue to happen more frequently over the next few decades. 

“The kind of temperatures we might have seen every fifty years we’re now seeing every five or so years, and by around 2050 this won’t even be a particularly hot summer,” Professor Larkin says. So while we can’t say for certain that climate change directly caused the recent heatwave, the likelihood of it occurring undoubtedly was increased by changes in our climate.

But what about the impact of this heatwave? Dr Scott Hosking is a Global Climate Modeller at the British Antarctic Survey in Cambridge, whose work focuses on understanding what drives year-to-year variability in climate and the changes in frequency and strength of extreme weather events. 

“The full impact of this global heatwave won’t be evident for many months,” he tells me, “but the high temperatures will have increased demand for air conditioning and energy consumption, and will have led to a reduction in crop yields affecting the price we pay as consumers.” 

Hosking also notes that the likelihood of droughts has increased (“warmer air can hold and carry more water… the warm air draws up more moisture from the soil”) but there could also be flooding because of heavy rainfall. “New research over the past year indicates that even if global temperatures were limited to an increase of 1.5C above pre-industrial levels,” Hosking says, “we are likely to expect increases in the frequency and nature of extreme weather events around the world.” 

ShortList’s scientifically-accurate rendering of the end of the world

So, yeah, you might get a bit more wear out of those expensive sunnies you always end up buying at the beginning of summer, but with heatwaves occurring more and more frequently, food is going to cost more and your house might end up flooding, so it’s not great news, on balance.

A milder concern is that, at present, things are just a bit uncomfortable. Dr Hosking  explains that UK homes, offices and schools are “poorly designed or inadequate” to shield us from extremes in temperature,” particularly as temperatures continue to increase. 

“Glass-fronted and poorly ventilated buildings trap heat inside increasing demand for air-conditioning,” he says. The good news is there are many engineering solutions that can be adopted to reduce or even remove the need for cooling, including “strategically planting trees to both provide shade and divert airflow around buildings, using new highly insulating materials, and designing internal spaces which facilitate natural ventilation.”

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Beyond “more trees” (good), is there anything else we, or the government, can do to prevent further climate change? 

The bad news is that we can’t really reverse the damage that we’ve already done, at least not unless we develop new technologies that are capable of removing CO2 from the atmosphere which, as Naomi Klein explains in her must-read book This Changes Everything, is extremely unlikely to happen anytime soon, if ever. What we can do is stop how much worse it gets. 

In 2016, the 196 signatories of the Paris Agreement committed to keep global average temperatures to well below 2˚C increase from pre-industrial times, with an ambition to limit the increase to 1.5˚C. The Agreement requires its signatories to put forward their best efforts to try reduce CO2 emissions in line with nationally determined targets that take into account each signatory’s domestic circumstances and capabilities, and includes requirements that all Parties report regularly on their emissions and their implementation efforts. But, of course, President Trump notably withdrew America from the agreement in 2017.

For countries committed to tackling climate change, the accountability that the agreement encourages in undoubtedly is a positive step in the right direction, but it goes without saying that we actually need to be making the positive changes to ensure that we are able to keep the promises that it entails. 

Later this year, the signatories are set to “take stock of collective efforts in relation to progress towards the goal set.” According to Professor Larkin, this is likely to show that we are currently heading towards a temperature increase “closer to 3°C than 2°C, and far away from our 1.5°C target.”

Trump withdrew America from the Paris Agreement in 2017

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This kind of temperature increase would have catastrophic consequences. As Dr Hosking explains: “New research indicates that a future 2°C increase will lead to more of us living under the threat of flooding, heatwaves and drought, while simultaneously applying a greater strain on our global food, water and energy resources.” This is likely to “disproportionately hurt poorer communities who are already struggling to withstand extreme weather events, and will find it difficult to adapt without the help of other nations.”

A recent comprehensive piece in the New York Times, compiled by writer Nathaniel Rich over 18 months, lays out what will happen if the world warms by more than 2°C: 

“Three-degree warming is a prescription for short-term disaster: forests in the Arctic and the loss of most coastal cities… Four degrees: Europe in permanent drought; vast areas of China, India and Bangladesh claimed by desert; Polynesia swallowed by the sea; the Colorado River thinned to a trickle; the American Southwest largely uninhabitable. The prospect of a five-degree warming has prompted some of the world’s leading climate scientists to warn of the end of human civilization.”

Efforts need to be urgently increased if we are to avoid this reality. According to Professor Larkin, most of us are “still not really recognising the urgency of this problem.” Educating people about climate change is incredibly important, because “if the public are seen to passionately care about this issue, it’s much easier for the government to introduce more radical policy,” and therefore more likely that we will be able to meet the ambitious targets set by the Paris Agreement.

For all the potential negative consequences such a prolonged period of excessively hot weather might have, I wonder if the recent heatwave might actually have a positive impact on the public perception of just how urgently we need to address this issue, given how much it has occupied the news cycle in recent weeks. But while outlets in the UK have been reporting on the abnormally hot weather, many continue to underplay or even completely ignore the role that climate change has played in causing this. 

Professor Larkin believes that “while the heatwave certainly brings [climate change] to our attention in a way that is arguably helpful… in all likelihood it will go away from the public consciousness once it cools down.”

So what can we do to start having a lasting impact? Well, for a start, it’s fair to say that we’re all aware of the urgent need to accelerate the global transition to clean and renewable energy sources, which don’t contribute to increasing the concentration of CO2 in our atmosphere. 

“CO2 emissions lead to an accumulation of CO2 in the atmosphere because CO2 has a long lifetime which means concentrations continue to rise even if CO2 emissions remain at the levels we are producing them today. This means that we need to start to rapidly cut global emissions,” says Professor Larkin.

“With a more rapid and urgent reduction in emissions, the CO2 concentration should start to reduce, but this will depend on how deeply and quickly we can cut those emissions, and it is unlikely that in the coming decades the CO2 concentrations will also start to fall. But shifting our energy system away from fossil fuel is a bit like turning an oil tanker – which means that we will continue to experience more climate change for the time being, even while we are working hard to reduce CO2 emissions. This shouldn’t be a reason not to take action – on the contrary – if we don’t take urgent action – the impacts will become even more severe.”

The irony, of course, is that as individuals we also make the situation worse long-term by switching on our fans and air-con in the short-term. Larkin is surprised by how little basic awareness people have about how to reduce their own carbon footprint. “Air conditioning, for example, uses a lot of energy,” she explains, saying that even in her own office people have automatically been using air conditioning units during the hot weather without first opening a window or closing the blinds.

Ultimately, then, it’s a change in the public perception that will have the biggest impact on our attempts to reduce climate change in the years to come. Otherwise, to recap: famine; floods; sold-out Twisters. 

As Dr Hosking says, “managing climate change while maintaining a global strong economy and healthy society is the grand challenge of our generation,” – it really is time that we started recognising it as such.

(Pics: Getty)