Heat waves: The worst is yet to come

For more than 30 years, scientists have been warning of the increased impact of heat waves due to climate change. The summer nightmare experienced in recent days in different European countries has left 1,055 estimated deaths in Spain, well over 100 thousand acres burned by forest fires, road and railway collapses, a derailment, agricultural losses... Meanwhile, the US is experiencing a heat wave of its own that is expected to last through Tuesday. The National Weather Service has issued excessive heat advisories and on Monday warned in a tweet that “heat will be an issue in parts of the East, the south-central US and begin building in the Northwest.”

However, the biggest cause for concern is not that this episode of extreme heat once again confirms the very real threat of global warming, but rather that what is to come is even more alarming. Indeed, this is only the beginning, since emissions that cause climate change continue to increase in the atmosphere and multiple signs point to serious difficulties for the political agenda in the fight against climate change.

In Europe, due to an energy crisis made worse after the Russian invasion of Ukraine, several countries have decided to go back to using coal (the worst fuel for the climate) in an attempt to mitigate the situation. On the other side of the Atlantic, July has dealt a serious blow to the green plans of the Joe Biden Administration, with a Supreme Court ruling that has severely limited the president’s ability to make progress on that front. Aggravating this is the resistance to legislative action by a Democratic senator who is indispensable to securing a majority. China, another major user of fossil fuels, continues to show a preference for coal. Last week, the Secretary General of the United Nations, António Guterres, described the lack of action on climate change as “collective suicide.”

The meteorological dynamic that develops amid these political vicissitudes is unmistakable. “This is one of the most solid issues in climate science: heat waves on land and in the sea are a direct consequence of global warming, and for any additional increase in this warming, they are expected to become more frequent, more intense and more durable,” says Valérie Masson-Delmotte, co-chair of group I of the most important panel of experts on climate change in the world, the Intergovernmental Panel on Climate Change (IPCC), which between 2021 and 2022 has presented its sixth scientific evaluation. It’s clear that the heat is going to intensify; the question is, will humanity put a stop to the growing threat?

As the French climatologist explains, the first IPCC reports from 1990 warned of an increase in heat waves due to global warming. “For many, it’s been more comfortable to ignore this information, but when it’s your turn to suffer, you realize the urgency to act,” she points out.

In reality, it’s difficult even for many climate scientists to have a clear idea of what it really means in our lives that the planet continues to warm by one or more degrees Celsius. One way to get an idea of the changes expected is to imagine that in 28 years, Madrid (Spain’s capital) will have a climate similar to Marrakesh (Morocco), winters in Montreal (Canada) will feel like those of Washington DC right now, and Los Angeles’ climate will be a lot like Gaza City’s. Though only an approximation, this was calculated by a 2019 study, published in PLOS ONE, which analyzed the climate forecasts for the year 2050 of the 520 most important cities around the world, finding cities whose current climate would most resemble them. This, in an optimistic scenario, in which the temperature of the planet does not rise by more than two degrees Celsius (3.6 degrees Fahrenheit).

Although scientific forecasts of the planet’s climate lose precision when the focus is on specific locations, these comparisons between cities assure us that every population is going to have to adapt to a new, hotter climatic reality. As specified by the meteorologist Juan Jesús González Alemán, from Spain’s meteorological agency Aemet, a large part of that country must prepare for an Africanization of its climate. “We are not used to more than two weeks of above-average temperatures as we’ve seen in this heat wave, but in 30 years, this may be the norm” he warns.

Until now, it is estimated that the average temperature of the planet has already increased by 1.1 degrees Celsius compared to the pre-industrial era, as a consequence of the emissions generated by vehicles, energy installations, industries, houses, food production (and in general, by the use of oil, gas and coal). An increase of 1.1 degrees Celsius may not seem significant, but the recent heat waves and other extreme weather patterns over the last year around the world already show what it means in practice. What’s most alarming is that there is still no indication of when or if this increase in global temperature will be capped. And, in the specific case of heat, the latest IPCC scientific assessment warns that every additional 0.5 degrees Celsius of global warming “causes clearly perceptible increases in the intensity and frequency of extremes of heat, including heat waves and heavy precipitation.”

Despite the warnings of science, the harsh reality is that humans, with their vehicles, their houses, their industries, continue to increase emissions that accumulate in the atmosphere. In fact, scientists are already clear that in the next 20 years the planet’s temperature will exceed the 1.5-degree Celsius cap, one of the two safety limits set by the Paris Agreement against climate change. There is still a window to reduce global warming, but with countries’ current emission reduction commitments – if they are met – the temperature would not be lowered, but the limit of two degrees Celsius would be exceeded, which further aggravates the forecasts.

Masson-Delmotte emphasizes that the fate of climate will be sealed in the coming years. “By 2040-2050, we may have achieved a stabilization of warming, or we might have already reached two degrees Celsius around 2050, this depends on the trajectory of greenhouse gas emissions, in particular, during the next decade.” To avoid the worst outlook, IPCC scientists have stated that global emissions should peak in 2025 but then fall sharply over the subsequent 30 years, almost disappearing in the second half of the century. This would require, among other measures, freeing humanity from its near total dependence on fossil fuels (oil, coal, and gas).

What would the planet look like with an even greater increase of four degrees Celsius? According to the most rigorous IPCC climate atlas available, which references large regions of the world rather than countries or cities, when a person born in 1970 in the Mediterranean reaches the age of 70 (in 2040), they will experience an average of 15 more days per year above 40 degrees Celsius (104 degrees Fahrenheit). But in a pessimistic scenario, in which the planet warms by more than four degrees Celsius, another individual who was born in 2010, perhaps your child, when turning 70, will experience 25 more days a year above 40 degrees Celsius. And if this person lives in Africa, he or she will have to face another 89 days in those extreme temperatures. These examples highlight a great territorial and generational injustice, since those who are going to bear the brunt are the generations who will inherit a problem created by others.

Scientists say that there is still time to change course. However, the energy crisis exacerbated by the invasion of Ukraine is again disregarding a response to the climate emergency, and even favoring a return to coal in the EU to reduce the high dependence on Russian gas. “It looks bad, because what’s being proposed in Europe and other countries like China is heading in the wrong direction. Allowing coal again is outrageous,” says José Luis García, head of Climate Change at Greenpeace Spain. “The energy crisis and the climate crisis have the same root, which is fossil fuels. The only way to solve both problems is to reduce their use until they are no longer used at all.”

Like an overflowing bathtub, the first reaction to a climate emergency should be to turn off the emissions tap. But at the same time, the recent episode of extreme temperatures has highlighted the urgency of learning to deal with impacts that can no longer be avoided. As has been verified in the United Kingdom, unforeseen events have an even greater impact in countries less accustomed to the heat.

It’s clear that this issue cannot be solved with more air conditioning alone, and many things need to be reconsidered, from the design of cities, which are especially vulnerable to extreme temperatures, to work activity and even tourism. “We cannot continue to function as a society in the same way as before,” says García, who recalls that what we are experiencing is a global warming of 1.1 degrees Celsius. “As the global temperature increases, the adaptation required will be greater. But in some places there may come a time when there is no longer any possibility of adapting”, he emphasizes.

This is all related to extreme heat, but the climate emergency has other faces. As the climatologist Masson-Delmotte points out, “more attention is paid to the acute effects of global warming and extreme events, but less is paid to chronic effects, such as the loss of snow and high mountain glaciers, which are going to reduce the water availability of many regions in dry seasons. The gradual rise in sea level is also extremely important. Right now, its effects are not very visible, but an increase in frequent flooding due to high tides is yet to come.”