"I've seen torrential rain in the desert", this was the unique experience of the protagonist in the song.
Recently, the Mediterranean storm "Daniel" penetrated deep into the Sahara Desert, bringing not only heavy rain, but also flooding. On September 10, Hurricane Daniel made landfall off the coast of Libya, a country of the Sahara Desert, bringing with it a large amount of precipitation equivalent to 2 to 10 times or even more than 10 times the annual precipitation there. The resulting floods have so far killed more than 11,000 people and left more than 10,000 people missing, as well as the bursting of two dams upstream of the country's city of Derna.
Under climate change, extreme rainstorms coincide with extreme heat. According to data released by the World Meteorological Organization and the Copernicus Climate Change Service, the European Union's climate monitoring agency, June, July and August this year set new records for the highest temperature in the same period since global records began, and this year is likely to become the "hottest year in human history". Thousands of people have died from heat in Europe this summer, and more than 6,100 bushfires have occurred in Canada so far this year.
From the extreme heat that has swept across Europe and across the United States, to the wildfires in Canada and extreme flooding in Europe, Africa and Asia, extreme weather threatens lives and livelihoods around the world, and it's time to face climate change.
Extreme rainstorm: "It rained for 2 or even 10 years in one day"
On September 4, Hurricane Daniel formed in Greece and was named after the Greek National Meteorological Service. On September 5-6, Hurricane Daniel brought record rainfall to Greece. A measuring station in the village of Zagora reported 750 millimetres of rainfall in 24 hours, equivalent to 18 months of rainfall. Later, as it descended south to the Mediterranean, the storm evolved into Hurricane Daniel in the Mediterranean. On the 10th, "Daniel" landed on the Mediterranean coast of eastern Libya and continued deep into the Sahara Desert. Benghazi, Sousse, Beida and other cities and surrounding areas were flooded, and the daily rainfall in Beida City set a new record of 414.1 mm.
The hardest hit was the city of Derna, on Libya's northern coast, where violent flash floods broke two aging dams and flooded entire neighbourhoods of Derna. The United Nations Office for the Coordination of Humanitarian Affairs reported on September 16 that the death toll from flooding in Libya rose to 11,300, with more than 10,000 missing in the Derna region alone. In an interview with the media, an official of the country's civil aviation department and member of the emergency committee, said: "The situation in Derna is catastrophic, it is no exaggeration to say that 25% of the city has disappeared. ”
Images after floods in the eastern Libyan city of Derna on September 11 Source: Xinhua News Agency
Most of Libya has a tropical desert climate, and only a few areas along the coast have a Mediterranean climate, and summer precipitation is basically zero. Even in winter, Libya has never recorded more than 100 mm of precipitation in 24 hours since meteorological records began. The Mediterranean storm brought Libya 2 to 10 times or even more than 10 times the annual precipitation, and the Derna River basin can be said to have "rain for 2 or even 10 years in one day." Zhu Dingzhen, former chief of meteorological services at the Public Meteorological Service Center of the China Meteorological Administration, said that Libya is a desert area and has weak resilience to heavy rainfall, and is prone to flooding if it encounters heavy rainfall. At the same time, Libya's poor infrastructure and poor resilience have led to severe flooding and casualties.
Hurricane Daniel is a Mediterranean storm that exists in the Mediterranean Sea and is a weather system that combines the attributes of a tropical cyclone and a mid-latitude storm, and is generally classified as a subtropical cyclone. Because the Mediterranean Sea itself is relatively narrow and long, it is relatively rare for a "Mediterranean storm" to develop into a mature "Mediterranean storm" in the Mediterranean, generally forming only 1 or 2 times a year, and the heavy rainfall brought by it often does not last long. However, in recent years, the Mediterranean Sea has repeatedly experienced higher SSTs, and the probability of storms has increased, which is inseparable from the background of global warming. Some experts predict that in the future, Mediterranean storms may appear more frequently.
Around the same time, parts of China's Guangdong province and Hong Kong, far from Libya, also experienced an extreme rainfall. From September 7 to 8, the daily rainfall of meteorological observation stations in Panyu and Nanhai, Guangdong exceeded historical extremes, including 2, 3, 6, 12, 24, 48 and 72 hours of rainfall in Shenzhen in Guangdong on the 7th. According to the Hong Kong Observatory, the 24-hour rainfall of 647.7 mm exceeded the intensity of the "7.20" rainstorm (645 mm) in Zhengzhou in 2021, equivalent to about a quarter of the annual rainfall. Hong Kong's highest level of black rainstorm warning signal lasted more than 14 hours, breaking the record of 5 hours and 47 minutes on August 23, 1999, and has become the longest lasting black rainstorm warning signal in Hong Kong.
Hong Kong experienced extreme rainfall
At that time, Typhoon Anemone unexpectedly strengthened as it passed through the Pearl River Delta region, directing the wet southeast water vapor from the Taiwan Strait and the warm and humid southwest water vapor from the South China Sea to converge over Hong Kong, forming a violent rainfall belt. This rain belt guided torrential rain clouds like train cars, hitting the Pearl River Delta region one after another, causing extremely heavy rainfall. Sun Shao, an associate researcher at the Chinese Academy of Meteorological Sciences, said in an interview with the media that according to his preliminary assessment, the temperature and ocean surface temperature in the range of the "sea anemone" are significantly higher. In particular, the sea surface temperature in the northern part of the South China Sea reaches about 30 degrees Celsius, constantly providing energy for the "sea anemone", and then the rain falls in the urban areas of the Pearl River Delta, causing great losses. "Despite the effects of climate change, the number of typhoons in the Western Pacific and the number of landfalls on the continent have not changed significantly. However, the probability of super typhoons is increasing. This is mainly due to the effects of warming on ocean temperatures and atmospheric conditions. The changing characteristics of typhoons affecting China can be summarized as follows: greater intensity, complex and variable paths, expanded impact range, and increased disaster risk. Sun Shao said.
Sun said his team's research shows that the frequency of extreme precipitation events is increasing in areas where total global precipitation is increasing. The frequency of extreme precipitation events is also increasing in areas where precipitation decreases but interannual variability increases. Extreme precipitation events tend to decrease only in areas with reduced precipitation and reduced interannual variability, such as the Mediterranean coast, Australia, and northern Central and South America. In addition to these regions, the frequency of extreme precipitation events on land is increasing globally.
Extreme heat: "This year is likely to be the 'hottest year ever'"
In addition to extreme precipitation, high temperature weather has also been frequent this year.
Since June this year, the United States, Japan and many European countries have suffered heat waves, and the temperature in many places has repeatedly reached new highs. NASA's Goddard Institute for Space Research obtains surface temperature data through tens of thousands of weather stations, as well as sea surface temperature data and aggregates temperature records through shipboard and buoy instruments. The data showed that the combined temperatures in June, July and August of this year were higher than the same period recorded by NASA and 1.2 degrees Celsius above the average summer temperature between 1951 and 1980. Data released by the World Meteorological Organization and the European Union's climate monitoring agency Copernicus Climate Change Service on September 6 also showed that the global average temperature in July and August this year were the first and second hottest months since records began in 1940, respectively. The global average temperature reached 16.82 degrees Celsius in August, 0.31 degrees Celsius above the original record set in 2016 and about 1.5 degrees Celsius above the pre-industrial average between 1850 and 1900.
On July 12, in Athens, the capital of Greece, men wash their faces at the fountain to cool off. Xinhua News Agency (Photo by Panayotis Moscadreou)
Under the influence of high temperatures, extreme weather events occurred frequently around the world throughout August: the Maui wildfire, Hawaii, became the deadliest wildfire in the United States this century; More than 6,100 forest fires have occurred this year, and the cumulative area of fires has reached 164,000 square kilometers so far, continuing to break historical records. As of September 7, there were still more than 1,000 wildfires burning in the country, of which about 650 were out of control; Phoenix, the capital of Arizona, USA, has a maximum temperature of more than 43 degrees Celsius for a month in a row, and the state has entered a "high temperature emergency".
The scene of a forest fire in West Kelowna, British Columbia, Canada, August 17.
By September, the high temperatures had not subsided. On September 5, local time, 43 of the 96 provinces in mainland France issued a high temperature yellow warning. On September 4, 200 weather stations across France detected the day's temperature, breaking the local record for the highest temperature in September. According to statistics, France has experienced 29 hot weather since 2000, compared with only 17 between 1947 and 2000. In France, high temperatures still occur after August 15 are quite rare, only six since 1947. The UK has also continued to be hot since September, as of the 8th, the temperature has exceeded 30 degrees Celsius for five consecutive days, setting a new record for 5 consecutive days, and the Met Office said that climate change has caused continuous high temperature weather to become more frequent and serious.
A woman rides a sightseeing bus in London, England, on September 6. Xinhua News Agency (Photo by Stephen Cheng)
While the northern hemisphere experienced the hottest summer in history, the southern hemisphere also experienced warm winters, with temperatures well above average in Australia, Antarctica and some South American countries. According to the New York Times a few days ago, Buenos Aires, the capital of Argentina, broke the record for the highest daily temperature in 81 years on August 2, and the maximum temperature on that day reached 30 degrees Celsius. Normally, the maximum temperature in Buenos Aires is around 15.6 degrees Celsius at this time of year.
In addition, the average global ocean temperature has also reached a new high. Except for the poles, the global average sea surface temperature exceeded the highest set in March 2016 every day in August, except for the polar regions. Sea ice in Antarctica fell in August to its lowest level since satellite monitoring began in the 70s, about 12 percent less than in the same period of the previous year. The Copernicus Climate Change Service said that the oceans, which account for more than 70% of the Earth's surface, have been at high surface temperatures for three consecutive months since June, with an average temperature of 20.98 degrees Celsius in August, also setting a new record high. With four months left in 2023, this year is already the second hottest year on record, just 0.01 degrees Celsius below the record high of 2016, according to the Copernicus Climate Change Service. If the temperature is normal this winter, this year will most likely break the 2016 record and become the "hottest year on record".
Climate change is behind this
On September 8, the Secretariat of the United Nations Framework Convention on Climate Change (UFCCC) released a major report saying that the trend of global warming is more rapid and severe than expected, and the overall situation is not optimistic. Comparing countries' pledges with actual global emissions, the report finds that since the Paris Agreement came into force in 2016, despite considerable progress in reducing emissions and taking action to adapt to extreme weather, the world still faces an implementation gap of 20.3 billion tonnes to 23.9 billion tonnes of CO2 equivalent by 2030, despite considerable progress in reducing emissions and taking action to adapt to extreme weather. The report notes that extreme weather and climate events, sea-level rise, land degradation and biodiversity loss are all closely linked to greenhouse gas emissions from human activities.
People rescue people in flooded neighborhoods in Pasufonto, Rio Grande do Sul, southern Brazil, on September 4.
The report finds that current emissions reduction commitments and efforts are far from sufficient to address the climate crisis, requiring more ambitious solutions and practical actions. Global greenhouse gas emissions need to be reduced by about 43% by 2030 compared to 2019 levels to achieve the goal of limiting global warming to 1.5 degrees Celsius above pre-industrial levels. The report makes clear that the global "window for reducing emissions" is closing rapidly, so countries must step up their efforts to implement stricter emission reduction measures and sustainable development plans to meet the greenhouse gas reduction targets set by the Paris Agreement.
On September 14, a seminar on "anatomical sparrow-style" in-depth analysis of the "23.7" heavy rainfall forecasting technology in North China was held in the China Meteorological Administration, which pointed out that the "23.7" heavy rainfall in North China is an extreme event in the context of global climate change, which is no accident, and will face more frequent and extreme heavy rainfall in the future. It is foreseeable that climate change will have a serious impact on the world's economic development, people's livelihoods and the natural environment in the coming years and even decades. Nature is reminding us with disaster after disaster that in the context of global climate change, extreme weather is becoming more frequent and intensified, which may bring more serious threats to human beings, and many people's common sense of "impossible" and "rare" are quietly coming.
Comprehensive Xinhua News Agency, People's Daily, CCTV News, China Meteorological Administration, Economic Daily, The Paper, etc
(Reporter Qian Zheng)
[ Editor: Li Shiqi ]