Anyone spending time outdoors in the UAE or another Gulf country during the summer could be forgiven for wondering if the air could get any hotter.
With the mercury frequently heading beyond 40°C, and with humidity high, conditions outside can be very uncomfortable.
The unfortunate reality is that outdoor temperatures in the region can, and almost certainly will, get even hotter as climate change continues to exert its effects.
“So far, an increase of 0.45°C per decade has been observed on average in the Gulf region, although this may vary depending on the exact location,” said Dr Diana Francis, an assistant professor and head of the Environmental and Geophysical (Engeos) Laboratory at Khalifa University in Abu Dhabi.
The Gulf region is already a hotspot for extreme wet-bulb temperatures – the measurement that accounts for air temperature and humidity.
Once the wet-bulb temperature exceeds 35°C (when the air temperature is 46°C and the humidity is 50 per cent), the human body cannot dissipate enough heat by sweating. Such conditions can be tolerated only for limited periods.
Research published in 2020 found there had only ever been 14 occasions anywhere in the world when the wet-bulb temperature had exceeded 35°C and of these, eight were recorded in the Gulf region. All were during the previous two decades.
The study, published in the journal Science Advances, forecast that within the next several decades, the climate would have changed so that there would “regularly” be instances where the wet bulb temperature exceeded 35°C.
Another study, published in Reviews of Geophysics in 2022, predicted temperatures in the Middle East would rise by almost 0.5°C per decade.
The Eastern Mediterranean and Middle East region as a whole is warming almost twice as fast as the global average, scientists said.
Dr Francis said the worst-case scenario forecasts from the Intergovernmental Panel on Climate Change (IPCC) were for warming in the Gulf region of 2°C to 3°C by the 2050s, and 5°C to 6°C by 2100, when compared to temperatures in the 1985 to 2006 period.
“However, the same models show an increase in precipitations over the southern Arabian Peninsula and Gulf region, which may moderate the projected increase in temperature,” she added.
A reduction in the burning of fossil fuels “will help to limit additional increase in temperature and it is essential”, according to Dr Francis, although it would have the side effect of reducing the quantity of particles or aerosols in the air, which would allow more sunlight to penetrate and lead to stronger heating.
Temperature rises are not restricted to land, with the waters of the Arabian Gulf also getting hotter and harming marine life such as coral reefs, which have experienced “bleaching” events.
A recent Royal Society paper suggested the improved relations between Gulf countries could offer scope for greater co-operation over marine conservation as the sea faces “mounting marine threats made worse by climate change”.
While it remains uncertain exactly how temperature rises will play out, the science is clear that the Gulf region is set to become hotter.
“The heat extremes in the summer are becoming very much more extreme. This will continue,” said Prof Jos Lelieveld, who researches climate in the Middle East and Mediterranean at the Max Planck Institute for Chemistry in Germany and The Cyprus Institute.
“How bad it will really become depends on how many greenhouse gases we continue to bring into the atmosphere.”
As well as seeing temperatures increase, the Gulf region is likely to experience more extremes of weather, including tropical cyclones.
Research published last year showed that greater numbers of tropical cyclones were likely to form in the Arabian Sea as temperatures rise. These are likely to become stronger with an increased chance of making landfall on the Arabian peninsula.
The potential impact of cyclones was vividly illustrated in October 2021, when Oman suffered 14 deaths and $800 million worth of damage due to Cyclone Shaheen.
However, scientists have noted that the Gulf nations are in a better position than many countries in other regions to protect themselves by, for example, investing in improved sea defences to combat storm surges.
“There are many things cities can do to make them more resilient [to rising temperatures]” Prof Lelieveld said. “The roads do not need to be black; they can be any colour.”
In the US, some roads in Los Angeles have been sprayed with a grey-white covering called CoolSeal, which reports indicate can reduce their temperature by up to 8°C, because lighter colours reflect sunlight.
Improving the insulation of houses is another approach, Prof Lelieveld said, because better-insulated properties are slower to heat up.
As well as having traditional wind towers, the historical buildings in the Dubai neighbourhood of Al Fahidi use shaded pathways that create breezes. Such techniques can be employed on a larger scale, Prof Lelieveld said.
“Street canyons can be organised so the wind can bring some relief,” he said.
Dubai’s skyscrapers create an “urban canyon” effect that helps to limit temperatures, according to a study from 2020. The shade offered by the city’s taller buildings is also credited with limiting temperature rises.
As a result, during the day Dubai experiences a stronger “urban cool island” effect than is typical for a city, with the urban area as much as 3°C cooler than the surrounding desert, which heats up quickly because of the absence of vegetation and moisture.
At night-time the “urban heat island” effect comes into play as the city, with its artificial surfaces such as asphalt, retains warmth more effectively than the surrounding desert does.
Shading on modern buildings can help to reduce heating: a good example is the Al Bahar Towers in Abu Dhabi, which have moving hexagonal shades that open or close according to the sun's position.
Parks and gardens can also help to keep temperatures down. Trees offer shade that reduces the heating of the ground, while a cooling effect is generated by the release of water into the air by plants and soil, processes collectively termed evapotranspiration.
Native plants are preferable as they use less water, although studies have found that cactuses warm up quickly, so only certain varieties are suitable.
Whatever strategies are used, air conditioning will continue to be needed, but Prof Lelieveld said that cooling could be more efficient if it was communal. Some Chinese cities, including Beijing, have communal heating systems, offering an indication of what can be done.
“You can think about systemic cooling systems that cool several buildings,” he said. “It’s cost-efficient if you implement cooling to different houses.”
Dr Francis said that ideally air conditioning should be powered by solar energy, a sector in which the UAE has invested heavily, rather than by energy generated by burning fossil fuels.