What Will Happen if the World Breaches the 1.5°C Climate Threshold?
A local resident, forced out of his home – now engulfed by filthy water – with his six children and just a handful of possessions, couldn’t believe the scale of the flooding. He was quoted as saying that no one saw this level of devastation coming.
His words are as jarring as they are devastating. Even now, with the climate crisis a permanent feature in headlines and breaking news stories – with more of us than ever before fearing the near- and distant- future of the planet, its people, and its ecosystems – our lived experiences of climate change seem to defy all understanding. It’s hard – impossible, at times – to accept the devastation as it unfolds.
But the time will come for us all to accept it. Efforts to stop this warming in its tracks – to combat our reliance on fossil fuels by boosting our capacity for commercial solar and wind power, and to curb the release of carbon in other areas – have proven insufficient so far.
This week, it was confirmed that the world is on track to pass the 1.5°C climate threshold by the year 2027. Suddenly, we are all equipped with a clearer picture – one that none of us wanted to see.
Here’s what it means.
What is the threshold, and what does it mean?
Since 2015, when 196 parties signed onto the Paris Agreement – a treaty designed to combat climate change and hold many of the world’s nations to high standards for funding and implementing measures against global warming – a global temperature rise of 1.5°C has represented the event horizon.
In 2018, the Intergovernmental Panel on Climate Change (IPCC) published their Special Report on Global Warming of 1.5°C. it concluded that keeping global average temperatures from rising further than 1.5°C was imperative – but that doing so would require major changes in all parts of society. So, from some perspectives, a 1.5°C increase represents the best-case scenario – in others, it represents the worst.
Reaching the threshold would mean that, compared with the second half of the 19th century (1850-1900), the average global temperature was 1.5°C higher.
This may not sound like a debilitating increase. None of us can detect such a small shift in temperature, after all. But the shift would mean that the careful – and tenuous – balance that the world exists in at any given moment would falter, and the ramifications are expected to be severe.
This shift is on the cards for 2027, and it’s looking increasingly likely. In the space of just 3 years, the World Meteorological Association has announced an increase of 46% (from 20% back in 2020 to 66% in 2023), as a result of our continued reliance on fossil fuels and other polluting practices.
What happens if we pass the threshold?
If the average global temperature rises by 1.5°C, it will be the first time since humans started to walk the planet – a truly unprecedented moment in our shared history.
Of course, we won’t feel the shift itself, but we will experience – with increasing regularity – the ramifications of life on a warming planet. Over the course of the past 12 months, many parts of the world have recorded the highest temperatures on record – including the UK. On the 19th of July 2022, the temperature in Lincolnshire reached 40.3°C – 1.6°C higher than the previous record-breaker, recorded in July 2019. Throughout the UK, the sustained heatwave posed a very serious threat to the health and wellbeing of thousands of vulnerable people. A record-breaking number of serious fires were recorded, including the wildfire that destroyed many homes in Wennington last July.
These catastrophic events – and many other erratic weather patterns recorded across the globe – are the direct result of global warming. As such, they are exactly what we can expect to see more of – and with increasing severity – if the world surpasses that 1.5°C average temperature rise.
It’s important to keep in mind that the temperature shift needn’t be permanent. In fact, the World Meteorological Association is currently warning of temporary fluctuations – regular breaches of the threshold, rather than a single, momentous shift beyond it. This doesn’t mean the world won’t suffer, but that there will still be a chance for us to reverse some of the damage and stick to the ultimate goal laid out in the Paris Agreement.
Still, whether the average temperature increase lasts for a matter of weeks or years, vulnerable areas around the world will bear the brunt of this unprecedented event.
Shrinking Lakes
A new study published to Science in mid-May has revealed that, in the past thirty years, more than half of the world’s lakes and reservoirs have shrunk. This global phenomenon poses a serious risk not just to communities who depend on those freshwater sources to drink, but for agriculture and fishing, too.
Each year, the study found, 22 gigatonnes of water was being lost, cumulatively.
While it’s true that our dependence on these water sources contributes to their depletion, by far the biggest contributor to this loss of freshwater is global heating – and increasingly erratic weather patterns, leading to reduced rainfall in some areas.
Arid environments are growing increasingly inhospitable, which means water is being lost more than ever. But, even in parts of the world that are known for their humid and wet conditions, water was being lost at a staggering rate.
If, as the WMA warns, we do begin to see average temperatures that exceed the 1.5°C threshold, then recent history suggests that lost water will threaten and displace more and more individuals and communities around the world. Demand will increase on fewer freshwater sources, and populations will grow increasingly concentrated as a result.
This loss of water will also pose a threat to the production of hydroelectric energy – an invaluable solution to our dependence on fossil fuels. Nations’ wind and solar capacities will need to be able to compensate for this loss, or we risk sliding back into old habits.
Loss of Food Security
Crop and livestock production are bound to suffer from the loss of freshwater sources, but also from drought and other erratic weather patterns. What’s more, livestock is expected to suffer more frequently from the impact of heat stress. At the same time, there is also a direct correlation between global warming and the prevalence of infectious diseases – many of which can threaten livestock, and lead to severe food shortages.
Warmer conditions make it a lot easier for certain disease-causing pathogens and vectors (like mosquitoes, which spread conditions like malaria and dengue fever) to thrive. With livestock suffering in suboptimal conditions, immunity will begin to wane – and, at the same time, the risk of transmission increases.
Vanishing Ecosystems
Some parts of the world are particularly sensitive to changes in temperature. Already, we are well aware of the impact global warming is having on arctic ecosystems, where melting ice is receding at an alarming rate, rapidly shrinking the landmass and causing a significant rise to sea level. The loss of ice is itself responsible for rising global temperatures – a vicious cycle that is proving hard to break out of. Wildlife is being lost, and large amounts of methane are being released into the atmosphere as permafrost melts.
As temperatures continue to climb, more ecosystems will come under immediate threat. Wildlife will be lost, with no hope of bringing certain species back.
Farmable, Liveable Land Will Be Lost
2022 saw deadly floods strike India and Bangladesh, killing 318 people, damaging thousands of villages, and displacing millions of people. Around 166,000 hectares of agricultural land was flooded – the direct result of unprecedented rainfall. Without homes and, in many cases, access to safe water, food and shelter, the people of India and Bangladesh also had to grapple with the rising threat of water-borne diseases like encephalitis.
Right now, Italy is seeing the worst flooding in more than a century. More than 13,000 have been forced to flee their homes as dirty floodwater breaches towns and cities. This year also saw New Zealand face the worst flooding in modern history, as up to 8,000 homes in Auckland were damaged.
A rise of just 1.5°C poses a significant risk to people, animals, and entire ecosystems. The climate emergency is already impacting our health, and it’s already taking a toll on areas that depend on extreme conditions – whether cold or arid, humid or dry – in order to keep the rest of the world in balance. We can only hope that this latest warning from the WMA is taken seriously, and that any increase in global temperatures is kept temporary – and as brief as possible.
