As Greece experienced the worst fires the country has seen in the past weeks, torching forests and homes, the UN issued their climate change report with intense warnings about the rapid upward rise of global temperatures.
With Greece recording ground temperatures of 115 degrees, it was no wonder that the resin within pine trees was explosive in an arid, drought-ridden environment.
The Intergovernmental Panel on Climate Change (IPCC) Report was released on August 9. Many of the changes recently observed in the climate are unprecedented, and some of the changes already set in motion — such as continued sea level rise — are irreversible over thousands of years.
The forecast clearly states that Greece should expect more heat waves, weaker winds and less overall precipitation. And at the same time, beaches and coastlines will be lost as sea levels continue to rise.
Climate Change Report “Reality Check”
“This report is a reality check,” said IPCC Working Group I Co-Chair Valérie Masson-Delmotte. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”
Strong and sustained reductions in emissions of carbon dioxide and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize, according to the IPCC Working Group I report, “Climate Change 2021: the Physical Science Basis,” approved on Friday by 195 member governments of the IPCC.
The report projects that in the coming decades, climate changes will increase in all regions. About two degrees Fahrenheit is the forecast for global warming, with increasing heat waves, longer warm seasons and shorter cold seasons. At four degrees Fahrenheit of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.
On the heels of the recent devastating wildfires, Greece’s Prime Minister Kyriakos Mitsotakis spoke at a press conference about the impact that climate change has had as blazes continued around the country. “The climate crisis is here and is showing us that everything must change. The facts demand bold solutions for which I am ready,” Mitsotakis told the Greek public.
“We are judged by the results. Last year we had only a few fires,” Mitsotakis admitted. He continued by saying that Greece’s heat waves were unprecedented, something which many scientists have blamed on climate change, and made for the perfect environment for fires to spread.
Sea Levels Expected to Rise In Greece
But it is not just about temperature. Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas, as well as coastal erosion. Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century. A total of 234 scientists and 14,000 reports came together to create the report.
For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.
“It has been clear for decades that the Earth’s climate is changing, and the role of human influence on the climate system is undisputed,” said Masson-Delmotte.
The report also shows that human actions still have the potential to determine the future course of the climate. The evidence is clear that carbon dioxide is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.
Less Rain, Less Wind, More Heat in Greece
The report focuses on Greece with its specific fact sheet focusing on Europe. A precipitation decrease is projected in Summer in the Mediterranean, extending to northward regions. Regardless of level of global warming, relative sea levels will rise in all European areas except the Baltic Sea, at a rate close to or exceeding global mean sea level. Changes are projected to continue beyond 2100.
Global warming in Greece means that according to climatic simulations for 2100, in the case of the IPCC Α2 scenario with up to 250 percent more greenhouse gas emissions in 2100 compared with 1961-1990, the mean maximum temperature over the entire Eastern Mediterranean is projected to increase.
In Greece, the increase is expected to be about 14 to 16 degrees Fahrenheit in southern regions, including the area of Athens. In central and northern Greece the increase is higher, varying between 16 to 20 degrees Fahrenheit. In June and September the increase of the maximum temperature is slightly lower, varying from 12 to 16 degrees Fahrenheit in Greece.
Extreme sea level events will become more frequent and more intense, leading to more coastal flooding. Shorelines along sandy coasts will retreat throughout the 21st century. In the Mediterranean an observed increase in hydrological and agricultural and
ecological droughts is expected with a projected increase in aridity and fire weather conditions at a global warming of two degrees Celsius and above.
A projected combination of climatic impact-driver changes that include warming, temperature extremes, increase in droughts and aridity, precipitation decrease, increase in fire weather, mean and extreme sea levels, snow cover decrease, and wind speed decrease is expected by mid-century and a global warming of at least four degrees Fahrenheit and above.
Although global climate models vary in many ways, they agree on this: The Mediterranean region will be significantly drier in coming decades, potentially seeing 40 percent less precipitation during the winter rainy season.
MIT Researchers Explain Mechanism in Mediterranean
An analysis by researchers at MIT has now found the underlying mechanisms that explain the anomalous effects in this region, especially in the Middle East and in northwest Africa. The analysis could help refine the models and add certainty to their projections, which have significant implications for the management of water resources and agriculture in the region.
The study, published in 2020 in the Journal of Climate, was carried out by Massachusetts Institute of Technology (MIT) graduate student Alexandre Tuel and professor of civil and environmental engineering Elfatih Eltahir.
Rainfall is expected to increase because warmer air carries more water vapor. “There is one major exception, and that is the Mediterranean area,” Eltahir stated, which shows the greatest decline of projected rainfall of any landmass on Earth.
“With all their differences, the models all seem to agree that this is going to happen,” he stated, although they differ in the amount of the decline, ranging from 10 percent to 60 percent. Previously no one had been able to explain why.
Tuel and Eltahir found that this projected drying of the Mediterranean region is a result of the confluence of two different effects of a warming climate: a change in the dynamics of upper atmosphere circulation and a reduction in the temperature difference between land and sea. Neither factor by itself would be sufficient to account for the anomalous reduction in rainfall, but in combination the two phenomena can fully account for the unique drying trend seen in the models.
The first effect is a large-scale phenomenon, related to powerful high-altitude winds called the midlatitude jet stream, which drive a strong, steady west-to-east weather pattern across Europe, Asia, and North America. Tuel stated the models show that “one of the robust things that happens with climate change is that as you increase the global temperature, you’re going to increase the strength of these midlatitude jets.”
But in the Northern Hemisphere, those winds run into obstacles, with mountain ranges including the Rockies, Alps, and Himalayas, and these collectively impart a kind of wave pattern onto this steady circulation, resulting in alternating zones of higher and lower air pressure. High pressure is associated with clear, dry air, and low pressure with wetter air and storm systems. But as the air gets warmer, this wave pattern gets altered.
“It just happened that the geography of where the Mediterranean is, and where the mountains are, impacts the pattern of air flow high in the atmosphere in a way that creates a high pressure area over the Mediterranean,” Tuel stated. That high-pressure area creates a dry zone with little precipitation.
A second mechanism is the reduction of the temperature difference between land and sea. That difference, which helps to drive winds
, will also be greatly reduced by climate change, because the land is warming up much faster than the seas.
“What’s really different about the Mediterranean compared to other regions is the geography,” Tuel stated. “Basically, you have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world.” While models show the surrounding landmasses warming by 3 to 4 degrees Celsius over the coming century, the sea itself will only warm by about 2 degrees or so. “Basically, the difference between the water and the land becomes less with time,” he stated.
That, in turn, amplifies the pressure differential, adding to the high-pressure area that drives a clockwise circulation pattern of winds surrounding the Mediterranean basin. And because of the specifics of local topography, projections show the two areas hardest hit by the drying trend will be the northwest Africa, including Morocco, and the eastern Mediterranean region, including Greece.
That trend is not just a projection, but has already become apparent in recent climate trends across the Middle East and western North Africa, according to the researchers. “These are areas where we already detect declines in precipitation,” Eltahir stated.
Eltahir has been working with government agencies in Morocco to help them translate this information into concrete planning. “We are trying to take these projections and see what would be the impacts on availability of water,” he stated. “That potentially will have a lot of impact on how Morocco plans its water resources, and also how they could develop technologies that could help them alleviate those impacts through better management of water at the field scale, or maybe through precision agriculture using higher technology.”
Geographically, the Mediterranean and the Arctic regions are considered to be the most vulnerable to the effects of climate change on health, the report said.
Climate change imposes health risks. Increased exposure to high temperatures and extreme events such as floods and droughts, air pollution and allergens, the weakening of food and nutrition security, increased incidence and changing distribution of some infectious diseases as well as the growing risk of forced migration.