What is the impact on our country?, The world is experiencing the 29th El Ni ñ o event Weather | Climate | China

Recently, temperatures in many parts of China have frequently exceeded 40 ℃, and some have even broken records for temperature extremes in local observation history during the same period. From a global perspective, data from the National Center for Environmental Forecasting in the United States shows that since the start of relevant statistics in 1979, the average surface temperature of the Earth on July 3 and 4 has set consecutive records.

The World Meteorological Organization announced on July 4 that El Niño conditions have formed in the tropical Pacific region for the first time in 7 years. It is expected that the temperature in most parts of the world will further rise in the future. There is a high probability of record extreme high temperatures in the next 5 years. Governments of all countries should respond to related climate events. Prepare.

What is El Nino? How does it affect the global climate? Will it become normal to heat earlier and hotter? The reporter interviewed Zhou Bing, chief expert of climate service of National Climate Center, and Xu Hongmei, chief expert of Climate Change Impact and Adaptation Room of National Climate Center.

El Nino can be understood as warm water phenomenon, the world is experiencing the 29th El Nino event

Q: What is El Niño? How does El Niño happen?

Zhou Bing: El Nino is an abnormal warming phenomenon that occurs in the surface waters of the equatorial Middle East Pacific Ocean. According to the national standard determined by El Nino, when the three-month moving average sea surface temperature in the key area of SST monitoring reaches or exceeds the climate average state of 0.5 ℃, it enters the El Nino state. If this condition persists for 5 months or more, an El Niño event occurs.

El Nino can be understood as a warm water phenomenon. When the equatorial Middle East Pacific abnormal warming, the rapid response of the tropical atmosphere, the equator south of the eastern and western air pressure showed a significant inverse correlation. The pressure field of Darwin Island and Tahiti Island has a seesaw oscillation, which leads to the weakening of the Walker circulation and a series of climatic anomalies in the tropics and the tropics. We generally call this seesaw oscillation the Southern Oscillation.

The production process of El Nino can be explained as follows: generally speaking, the equatorial Middle East Pacific is blowing easterly winds, so the warm sea water on the surface also flows from east to west, making the Pacific warm in the west and cold in the east. However, when El Nino appears, this easterly wind will weaken, while the westerly wind in the western equatorial Pacific will strengthen, the warm surface water in the western Pacific will rapidly expand eastward, and the subsurface cold water will rise, which will reduce the sea temperature in the western Pacific and increase the sea temperature in the equatorial Middle East Pacific.

In contrast, the La Nina phenomenon occurs when the sea surface temperature of the equatorial Middle East Pacific is abnormally low. Generally speaking, El Niño and La Niña occur alternately, and their cycles on the interannual time scale have become the strongest natural climate oscillations and the most important precursor signals in seasonal and interannual climate predictions. By analyzing the conversion law of El Nino and La Nina in the past 120 years, the cycle is generally 2-7 years, with an average cycle of 4 years. Since 1900, there have been 28 El Niño events and 29 La Niña events, and the world is experiencing the 29th El Niño event. With the intensification of climate warming, three super-strong El Nino events have been recorded since 1951, but only one strong La Nina event has occurred. The impact of climate change on this natural climate oscillation cycle change is not yet clear.

Q: How does El Nino stir up the global climate? What is the impact on our country?

Zhou Bing: Although El Niño is a regional phenomenon occurring in the equatorial Middle East Pacific, its power is global through ocean-atmosphere interactions. El Nino and global warming make global and regional climate change tend to extremes.

El Niño can raise global average temperatures, leading to the "hottest year in history". Since 1980, the global average temperature has set a record 12 times, 10 of which have occurred in El Niño years.

El Niño will directly cause severe extreme weather events such as high temperature, drought, and heavy rain in the tropical Pacific Ocean and its surrounding areas. For example, during the El Niño development period, the precipitation in southeastern Australia is abnormally low, southeastern Africa is abnormally dry, and the summer precipitation in India and China is more abnormal; during the El Niño period, the central coast of Chile is prone to heavy rains and floods, most of the Amazon River Basin and Northeast Brazil are prone to droughts, Indonesia, Malaysia, the Philippines and other places have reduced precipitation and frequent forest fires. There are more thunderstorms in the northern Gulf of Mexico and the southeast coast.

El Niño also has a significant impact on our climate. In the summer of El Niño development year, the temperature in southern North China, northern central China, central East China, and eastern Northwest China is prone to be on the high side. El Niño makes the autumn and winter precipitation in the monsoon region of northern my country less, which is easy to form meteorological droughts; in southern my country, the precipitation increases in autumn, which is prone to waterlogging disasters. El Nino also has a direct impact on the rise of winter temperatures, making it more likely to be a "warm winter" phenomenon.

The world is facing a hotter, drier and waterlogged future, with extreme heat becoming a "new normal"

Q: In the context of global warming, is it inevitable that "one year will be hot"? What will be the trend of extreme weather?

Zhou Bing: About 20 years ago, extreme heat began to attract widespread attention. In the summer of 2003, a heat wave swept the world, especially in Europe. The temperature in Italy was 6 ℃ to 10 ℃ higher than that in the same period of the year. The temperature in Switzerland was the highest in 200 years, and the high temperature in France was unprecedented in 150 years. The high temperature heat wave in Europe caused more than 30000 deaths. Among them, the death toll in France was close to 15000. Among them, heatstroke deaths accounted for about 9% of high temperature-related deaths; while cardiovascular and cerebrovascular diseases and respiratory diseases accounted for 30% of the total.

Since then, there have been a number of serious heat wave events around the world, such as the heat wave in the United States in July 2006, the Russian heat wave in July 2010, and the high temperature in Australia in 2019. In 2013, 2017 and 2022, large-scale high-temperature heat waves occurred in my country. Since June 2023, many consecutive high-temperature processes in the north have also become the focus of attention.

The world is facing a hotter, drier and waterlogged future, with extreme heat becoming a "new normal". At the same time, another feature brought about by climate change is becoming more and more obvious, that is, high temperatures start early, end late, and last longer. In the long run, human activities dominated by greenhouse gas emissions are not only the main cause of climate warming, but also greatly increase the probability of extreme high temperature heat wave events and heavy precipitation events.

High temperature and extreme heat will occur frequently in the following summer, but this does not mean that it will be hotter every year from now on. When southern my country experienced a high temperature and heat wave last year, there was a view that "although 2022 is already the hottest year in history, it may also be the coolest year in the next 10 years." This is a misunderstanding of the global warming trend. It is also a misunderstanding of the interannual variability of temperature. We should correctly understand the uncertainty of the results of long-term climate change projections based on scientific evidence.

Adhering to both mitigation and adaptation is China's national strategy to address climate change

Q: What is China doing to address climate change?

Xu Hongmei: Adhering to both mitigation and adaptation is China's national strategy to address climate change. Both are aimed at reducing the adverse effects of climate change and promoting sustainable human development. Among them, mitigation changes the climate system by reducing greenhouse gas emissions or increasing carbon sinks, while adaptation reduces losses by adjusting natural or human systems to respond to actual or expected climate change and its impacts.

In terms of mitigation, China has actively and steadily promoted carbon neutrality, issued specific policies for energy, construction, transportation and other sectors, and adopted a series of emission reduction measures. my country has incorporated the goals and tasks of responding to climate change into the five-year plan for national economic and social development, promulgated corresponding laws and regulations, and strengthened efforts to respond to climate change and control greenhouse gas emissions. The scale and consumption of renewable energy power generation in China have continued to increase in recent years, effectively promoting carbon emission reduction and pollution reduction. my country has also vigorously built low-carbon cities to promote regional emission reduction. In the pilot process, good practices and experiences on industrial transformation, energy transformation, technological progress, and low-carbon lifestyles have emerged, effectively promoting low-carbon policies from the bottom up. Implementation.

In terms of adaptation, my country is one of the countries most affected by climate change. It regards active adaptation to climate change as a major strategy for national economic and social development. The main methods include: First, it has formulated and implemented relevant plans and systems, and initially formed a complete adaptation Climate change policy and regulation system; second, the initial establishment of a climate change adaptation funding investment mechanism, which is initially dominated by national financial funds, commercial and financial adaptation funds and market inputs are supported, and international bilateral or multilateral adaptation funds are diversified investment mechanisms that supplement and actively attract corporate and social funding; third, vigorously implement key action projects to adapt to climate change. For example, since the 18th National Congress of the Communist Party of China, my country has implemented a series of ecological protection actions, proposed a series of ecological protection countermeasures to adapt to climate change, and actively carried out water conservancy construction actions, and a large number of controlled water conservancy projects have been completed and put into use., A large number of water storage, water diversion, and water lifting projects have been built, which has greatly improved my country's water resources control and drought and flood disaster prevention and flood disaster prevention capabilities.

As the two main ways to deal with global climate change, mitigation and adaptation have their own priorities and must be given equal emphasis. Mitigation and adaptation interact within and across regions, with intersections in the areas of water, energy, land use and biodiversity; some actions have both mitigation and adaptation features and can be synergistic. For example, forest land and wetland protection and ecosystem restoration not only enhance the resilience of the ecosystem, but also increase carbon sinks; for example, photovoltaic sand control plays a role in sand fixation to a certain extent while generating electricity from renewable energy. Conversely, deforestation and ecological damage, while increasing carbon emissions, cause soil erosion, which is detrimental to mitigation and adaptation.

Enhance the ability to adapt to climate change and strive to prevent and mitigate the adverse effects and risks of climate change

Q: The National Strategic 2035 on Adaptation to Climate Change proposes that a climate-resilient society will be basically completed by 2035 ". In the face of long-term adverse effects and sudden extreme events brought about by climate change, how can we better adapt?

Xu Hongmei: The global climate is warming significantly, and extreme weather and climate events are frequent. We urgently need to enhance our ability to adapt to climate change and prevent and resolve the adverse effects and risks of climate change. From the perspective of climate change impact, risk and adaptation, I think we should focus on comprehensive observation of the climate system, accurate prediction, disaster early warning and prevention.

Improve the comprehensive climate system observation station network and climate change database construction. This is the foundation of the foundation. We need to improve the comprehensive observation capability of the existing basic climate variables of the ground, sea, air and space climate system, and form a three-dimensional, open and interactive integrated climate monitoring system in China that includes multiple layers of the earth system. in particular, we should strengthen the monitoring of the impact of global warming on typical vulnerable areas in China.

Improve the ability to accurately predict climate change and extreme weather and climate events. We are exploring key feedback processes affecting seasonal to interdecadal climate change in China, strengthening research on multi-layer interactions of the Earth system and global and regional linkages, promoting and coordinating the development and improvement of Earth system simulators and regional climate change models, strengthening the development of high-resolution regional climate models, and providing accurate prediction and estimation of national and regional extreme events and temporal and spatial change characteristics on an age-to-centennial scale.

Improve the ability of meteorological disaster monitoring, forecasting and early warning and the ability of the whole society to prevent and respond to meteorological disasters. Building the first line of defense for meteorological disaster prevention and mitigation is the requirement of ensuring life safety, production development, affluent life and good ecology. We should continue to improve the meteorological disaster monitoring, forecasting and early warning system for different types of disasters and key industries, improve the early warning information release system, build a meteorological disaster risk assessment and decision-making information support system, and establish a meteorological disaster identification and evaluation system.

Develop climate change impact and risk assessment technologies, especially to establish an assessment system for key industries and fields. It is necessary to carry out quantitative and dynamic assessments of disasters in key directions such as food security, water resources, ecological environment, human health, and infrastructure; improve the assessment of climate change impacts and risks in key regions/river basins, and improve cities and economic zones Ability to adapt to climate change. In addition, it is necessary to strengthen the theory, method and key technology research of climate change adaptation.

Collaborative adaptation and joint governance can better promote adaptation to climate change. We should strengthen coordination and linkage, resource sharing, information exchange and mutual learning, such as establishing a joint working mechanism for climate change adaptation, exploring the establishment of an information sharing mechanism for climate change adaptation, regularly carrying out assessments of policies and actions for climate change adaptation, and deepening pilot projects for the construction of climate-adaptive cities, so as to promote the participation of multiple subjects and form a joint force for climate change adaptation.