What impacts are these areas facing under climate change?
Expert consultant:
Wei li, Director and Researcher of Climate Service Office of National Climate Center.
Huang Lei, Director and Researcher of Climate Change Strategy Research Office of National Climate Center.
Liao Yaoming, researcher, Climate Change Impact and Adaptation Office, National Climate Center.
Zhai Jianqing, Researcher of Meteorological Disaster Risk Management, National Climate Center
Zhang Baichao, Engineer, Climate Change Impact and Adaptation Room, National Climate Center
"Small probability" events are no longer "rare"
Extreme events are short for extreme weather and climate events, including extreme weather events and extreme climate events. Extreme weather events refer to events with low probability of occurrence, which usually account for only 10% or less of such weather phenomena. Extreme weather events refer to the average state of a large number of extreme weather events in a certain period, and its average state is also extreme relative to the climate average state of such weather phenomena. Extreme events generally have three characteristics: low frequency, high intensity and great social impact. In addition, some weather and climate states or events that are not extreme observed in a small space-time scale are sometimes called extreme events if they occur continuously in time or simultaneously in space.
But with the global warming, this kind of "rarity" is becoming less and less rare.
In the past 2022, frequent extreme events were like "rolling up and down" in a more unstable climate system, which made this "hot kettle" constantly send out worrying alarm sounds. On February 18th, the Atlantic storm "eunice" hit many countries in western Europe and other places, among which the largest gust was about 196 km/h in Needles, Isle of Wight, England, setting a record for the largest gust in English history. From June to August, continuous heavy precipitation caused about one-third of Pakistan’s land to be flooded; At the end of the year, from December 22 to 24, the "epic cold wave" swept across the United States. On the 23rd, the lowest temperature in some parts of the midwest of the United States dropped below -40℃ …
Extreme weather and climate events have also had a great impact on China’s economic and social operation. From May 21st to June 21st, 2022, the dragon boat water, the second strongest in history since 1961, affected the Pearl River Basin. More than 45 rivers exceeded the warning water level, and waterlogging occurred in urban and rural areas. From June 13th to August 30th, a large-scale continuous high-temperature weather process occurred in central and eastern China, which is the longest regional high-temperature weather process in China since 1961 …
According to the World Meteorological Organization, in 2022, weather, hydrology and climate-related disasters, including severe floods, high temperatures and droughts, have affected millions of people and caused economic losses of billions of yuan. Extreme events are widespread, frequent, strong and concurrent, and the "Pandora’s Box" of climate has been opened. How we should act has become an urgent problem to be solved together. (Zhao Xiaoni)
The food security risk is approaching quietly.
Affected by global warming, extreme drought, floods and other disastrous weather frequently occur again, which aggravates the global water shortage and food crisis. Since the middle of the 20th century, about one-third of the runoff of more than 200 major rivers in the world has obviously decreased, and the average yield of wheat and corn has decreased by 1.9% and 1.2% respectively every decade. In 2021, affected by extreme temperatures and floods, the prices of agricultural products such as Brazilian coffee, Belgian potatoes and Canadian yellow peas rose sharply.
The sixth assessment report of IPCC pointed out that more frequent heat waves, droughts and floods have exceeded the tolerance limits of some animals and plants, resulting in a large number of deaths of some trees and corals, especially in Africa, Asia, Central and South America, small islands and the Arctic. Africa is one of the most vulnerable regions in global food security. Since October 2022, the rainfall in the Horn of Africa has been less than 60% of the average level in the same period, and the famine caused by drought has seriously affected the region. In sub-Saharan Africa, drought has greatly reduced food production and triggered a serious food crisis. The decrease in precipitation and the increase in temperature have also aggravated the problem of pests and diseases. Since the beginning of 2020, affected by drought, desert locusts have invaded many parts of the world from Africa to South Asia, and caused irreparable losses to agricultural production in many countries. At the same time, climate change has also led to the expansion of agricultural pests and diseases to higher latitudes and higher altitudes, and the instability of agricultural production has increased. Because of the influence of climate change, the risks faced by the whole production links such as global grain planting, storage, processing and transportation are further increased.
Although global warming may bring some short-term benefits to agricultural production and grain output in some regions, in the long run, extreme weather and climate events caused by climate warming and their impact on agricultural production are more unfavorable and lasting. Therefore, it has become an important issue for all countries to take effective measures on a global scale and actively respond to the food crisis caused by climate warming. (Jane Jufang)

In 2020, the desert locust in Kenya broke out, which was the worst desert locust plague in the region for decades. Image source: United Nations News Network
The "number one killer" of biodiversity
Global climate change is one of the main reasons for the damage of biodiversity, including the impact on the geographical distribution pattern of species, genetic diversity, species diversity and ecosystem diversity.
The loss of ecological environment on which biological species or species groups depend is one of the biggest threats to biodiversity, while climate change intensifies the loss, fragmentation and degradation of biological habitats, and even moves to high latitudes and high altitudes, resulting in the narrowing or fragmentation of the distribution areas of some species. For example, the habitat of polar bears has shrunk due to the melting of glaciers, and their predation range has shrunk greatly. The lack of food makes it impossible for female polar bears to accumulate enough fat to produce milk, which seriously threatens their breeding.
At the same time, the population characteristics are also changing, resulting in the decrease of population and the disappearance of endemic species. Under the background of global warming, some turtles and crocodiles may face the risk of extinction. In addition, the diseases caused by climate change have intensified, which once made the amphibian species in North America tend to extinction.
Climate change will lead to changes in the structure, function, development and diversity of ecosystems. The once colorful underwater world is rapidly fading, and the uncontrollable "whitening" is eroding the Great Barrier Reef. On May 10, 2022, the survey results of Australian government agencies showed that 91% of coral reefs in the Great Barrier Reef were albino due to climate warming. The Great Barrier Reef is the largest tropical coral reef system in the world, and the rising sea temperature caused by global warming is accelerating the frequency and scale of coral bleaching. According to a special report of the World Meteorological Organization, 99% of coral reefs in the world are likely to disappear before the end of this century because of climate change.
In addition, climate change also causes the frequency of extreme weather and climate events to increase, such as snowstorms, floods, droughts and other weather, which damages animals and plants and destroys ecosystems. Changes in biodiversity will also adversely affect the climate system, thus further damaging biodiversity. (Liu Qian)

Climate change leads to the continuous increase of seawater temperature and acidification, which leads to coral bleaching. The picture shows the coral of the Great Barrier Reef in Australia. Source: Xinhuanet
The water cycle is intensifying, and extreme droughts and floods are "double-sided"
Water is closely related to all life on earth. The first Report on the State of Global Water Resources released by the World Meteorological Organization in 2022 shows that there are currently 3.6 billion people in the world who face water shortage for at least one month every year. It is estimated that by 2050, more than 5 billion people in the world will face water shortage.
Under the background of global warming, people can often feel the impact of climate change through hydrological changes, such as more intense droughts, more extreme floods and more irregular seasonal rainfall. The sixth assessment report of IPCC pointed out that with the further global warming, the global water cycle will be further intensified, the seasonal difference of water cycle will increase, the global daily precipitation intensity will increase, and the frequency of extreme precipitation events will increase. Extreme precipitation will increase in almost all areas, and strong precipitation events related to tropical and temperate cyclones will be further enhanced. Generally speaking, global warming will make the wet season wetter and the heavy precipitation events stronger.
The cryosphere is the most sensitive layer to global warming, and the temperature continues to rise, which makes the cryosphere in a state of melting and shrinking. Since the mid-1980s, glaciers have been melting rapidly, and the Arctic sea ice range has been shrinking continuously. Studies show that by 2100, if the global temperature rises by 1.5℃, nearly half of the glaciers will disappear; If calculated according to the relative extreme conditions of 4℃ rise, about 83% of the glaciers in the world will no longer exist by 2100.
At the same time, the melting of glaciers and the expansion of ocean warming will accelerate the rate of sea level rise. In 2021, the global average sea level reached the highest level since satellite observation records. By the year 2100, even if greenhouse gas emissions are greatly reduced and global warming is controlled far below 2℃, the sea level will rise by 30 ~ 60 cm. Sea level rise not only threatens people living in low-lying coastal areas, but also is closely related to ocean acidification, reduced oxygen content in seawater, glacier retreat, shrinking Antarctic sea ice and Greenland ice sheet, which will seriously damage the ecology of the ocean and cryosphere. (Wang Meili)
Energy system suffers from "indiscriminate attack"
Under the background of climate change, the frequency and intensity of global extreme weather and climate events are increasing, and the energy infrastructure has the characteristics of wide coverage, strong environmental dependence and high exposure. When extreme weather strikes, they will inevitably be affected, and the risk of being threatened by climate is also increasing.
For traditional fossil energy, although its power supply is relatively stable, coal transportation, natural gas pipeline transportation and power station operation will also be affected by extreme weather.
Extreme weather such as torrential rain, tropical cyclone and hail and related secondary disasters often cause direct damage to various energy infrastructures. Rainstorm and the flood disaster caused by it can easily lead to accidents such as pole-down disconnection and transformer short circuit in power grid system. Hurricanes, typhoons and other weather are the main threats to coastal energy infrastructure such as offshore oil and gas platforms and offshore wind turbines.
Photovoltaic power generation and wind power generation, which play the main role in energy transformation, are sensitive to abnormal temperatures. In photovoltaic power generation, extreme low temperature will easily lead to frost heaving of the equipment foundation, while extreme high temperature will reduce the power generation efficiency and service life of the panel. In terms of wind power, water vapor (rain, snow, frost and sea fog, etc.) in low temperature is easy to freeze on turbine blades, which affects the rotation of the wind wheel, while high temperature weather is easy to form a wide range of static wind environment, resulting in windless driving of wind turbines.
In February 2021, the energy supply system in Texas, USA, was completely hit by cold wave and low temperature weather. The low temperature caused the natural gas wellhead to freeze and the gas pipeline to freeze, and the natural gas output once dropped by 50%, resulting in gas-free power generation in the power plant; Insufficient power generation has caused natural gas mining to stop, further aggravating the power shortage. At the same time, wind turbines, which are responsible for 20% of the state’s power generation, are generally covered with ice and forced to stop, and a large number of photovoltaic panels cannot generate electricity due to snow cover …
It can be seen that whether it is fossil energy or renewable energy, the impact of climate change is often an "indiscriminate blow". Therefore, under global warming, human beings need to constantly improve the tolerance, operation and resilience of different energy facilities under extreme conditions in order to keep the bottom line of energy security. (Wu Peng)

On February 15th, 2021, affected by the cold wave and low temperature, a gas station was closed due to power failure in Houston, Texas, USA. Image source: Xinhuanet
The health impact of underestimated population
The sixth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC) points out that in the last 50 years, global warming is happening at an unprecedented speed since 2000, and the threat brought by climate change is intensifying. Studies show that climate change can directly or indirectly have many adverse effects on people’s health through various complicated paths, and no country can be immune to the health effects caused by climate change.
An editorial published by The Lancet in 2022 pointed out that the impact of climate change on health was greatly underestimated. It is understood that more than 5 million deaths every year can be attributed to abnormal high and low temperatures. Among the deaths related to high temperature, 37% can be attributed to climate change caused by human activities. High temperature weather will overload the human body’s own temperature regulation system, which will not only lead to heat-related diseases such as heatstroke and heatstroke, but also increase the risk of morbidity and mortality of cardiovascular and cerebrovascular diseases, respiratory diseases and urinary system diseases.
Climate change leads to a significant increase in the frequency and intensity of extreme weather events such as floods, droughts and typhoons, which will not only cause direct casualties, but also increase the risk of infectious diseases, non-infectious diseases and mental and psychological diseases. For example, extreme heavy rainfall and its flood disaster may change the geographical distribution of vector population, cause casualties and the outbreak of infectious diseases. Studies have shown that the risk of acute influenza, tuberculosis, dengue fever and other infectious diseases has increased significantly after floods. According to the Countdown Report on Health and Climate Change in The Lancet in 2022, compared with 1951-1960, from 2012 to 2021, the length of time suitable for malaria transmission in high altitude areas in America increased by 32.1%, and that in Africa increased by 14.9%. At the same time, under the influence of climate change, the global risk of dengue fever transmission has increased by 12%.
Under the influence of climate change, frequent droughts and changes in precipitation patterns have increased the prevalence and severity of wildfires, which can affect or worsen the condition of patients with respiratory diseases such as asthma through heat injury and smoke exposure. In addition, dust raised by sandstorms can damage human skin and respiratory system, leading to diseases such as tracheitis. (Luo LAN)
(Editor: Su Jessie)

















