It’s only March and it’s so hot. Will this summer encounter extreme heat?El Niño may make a comeback-Hangzhou News Center-Hangzhou Net

The temperature is soaring! my country has been warm and hot recently, and many places have experienced warm weather that is rare in the same period. As of March 7, the temperature of 102 weather stations had broken the record in early March. The same is true for Zhejiang. On March 9, the highest temperature in most of the province was between 25°C and 27°C.

However, the Zhejiang Provincial Meteorological Observatory predicts that from the 11th, Zhejiang will experience a process of strong cold air, with a maximum drop of 10°C.

Such a sudden change is bewildering. Many people are worried that it is only March and it is so hot. Will this summer experience the extreme high temperature for a long time like last year? Will the weather be unusual this year?

People’s concerns are not unfounded. A few days ago, the National Climate Center announced that the La Niña event that has lasted from around September 2020 to the present has a high probability of ending in early spring this year. There are also meteorological agencies predicting that the El Niño event may make a comeback this year, bringing more extreme weather.

The weather stage will usher in changes. Under the background of global warming, the climate state may enter a new stage of more complexity and uncertainty. How should we respond?

The temperature dropped sharply, and the weather in Hangzhou ushered in a big turning point on the weekend

Extreme weather events intensify

The La Niña event refers to the phenomenon that the sea surface temperature in the central and eastern Pacific Ocean continues to be abnormally cold, which is likely to trigger extreme weather events such as heavy rain, floods, and droughts on a global scale. During winter in my country affected by La Niña, cold air activities are frequent, and regional extreme cold events are prone to occur, causing economic and social losses.

The La Niña event did not change the overall warmer pattern—since December last year, the average winter temperature in Zhejiang was slightly higher than normal. However, strong cold air and cold waves occurred more frequently, and there were 4 cold waves alone. The temperature fluctuates from cold to warm, showing the unusualness of the current climate state.

At the Zhejiang Provincial Climate Center, Lei Yuan, a senior engineer, turned on the computer and showed the reporter a curve showing a fluctuating rise: from 1971 to 2000, the average temperature in Zhejiang Province was 16.8°C; from 1981 to 2010, the average temperature in the province was 17.2°C; and from 1991 to 2020, the average temperature of the province reached 17.6°C.

Meteorology refers to the annual average temperature as a unit of 30 years. From the data, the trend of warming is obvious.

In this trend, temperature fluctuations will also become larger and larger. “Global warming will make the atmosphere’s ability to store energy stronger, and release it more violently. The multiple rounds of cold air processes this winter have proved this,” Lei Yuan said.

More and more mainstream studies have shown that climate warming will lead to an increase in the frequency and intensity of extreme weather and climate events such as high temperature and heavy precipitation. According to the sixth assessment report recently released by the United Nations Intergovernmental Panel on Climate Change (IPCC), as global warming further intensifies in the future, the probability of occurrence of rare extreme weather and climate events such as extreme heat events and heavy precipitation is expected to increase.

At the beginning of the new year, extreme events occurred frequently – most of Europe experienced record-breaking high temperatures in January; floods occurred in the desert areas of Saudi Arabia; since January 20, the temperature in Mohe, the northernmost city in China, has dropped to minus 50 degrees Celsius for three consecutive days, setting a new record The coldest temperature ever recorded… which seems to mean that “unusual” has become the new normal.

In addition, there is another uncertain factor that cannot be ignored – El Niño. Some meteorological agencies predict that the El Niño phenomenon may “emerge” in the second half of this year.

El Niño is the opposite of a La Niña event, which means that the sea surface temperatures in the equatorial central and eastern Pacific Ocean continue to be abnormally warm. Recently, the World Meteorological Organization stated that if it really enters the El Niño phase, the world may usher in a new round of warming, and there is a greater possibility of climate anomalies in various places.

According to statistics from the Provincial Climate Center, there have been 21 El Niño events in Zhejiang since 1951. The last time I showed up was in November 2019. At that time, during the period affected by the El Niño event, the average temperature in the province reached 11.2°C, which was 1.8°C higher than the same period of normal years.

In Zhejiang, there have been La Niña and El Niño events successively in a natural year. There have been a total of 9 incidents in history, and the “handover” was completed before June of that year.

“According to past records, when El Nino ‘succeeds’ La Nina, the precipitation in the flood season in our province is generally less, and the number of high-temperature days is less than normal in the same period, but the meteorological disasters caused by typhoons may be more serious.” Lei Yuan said.

However, there is still uncertainty about whether and when El Niño will appear this year. “What is certain at present is that extreme weather events will intensify in the future, and there is still a high probability of periodic high-temperature weather this summer.” Lei Yuan said.

Some meteorological experts predict that this year, there may be extreme events such as heavy rains and mountain torrents during the rainy season in the middle and lower reaches of the Yangtze River, high temperatures in summer in the northern hemisphere, and strong typhoons in autumn.

Many industries face challenges

The temperature fluctuates sharply between cold and hot like a pendulum, coupled with the increase in the probability of extreme weather and climate events, the industry of “watching the sky and eating” is facing many challenges, and agriculture bears the brunt of it.

Last summer, the central and eastern part of my country experienced the strongest high temperature process since 1961. Affected by extreme heat waves, droughts are inevitable. According to data from the Zhejiang Provincial Climate Center, from July 5 to November 27, 2022, Zhejiang will experience a large-scale meteorological drought. This caught farmers off guard.

“I have been in the industry for more than 30 years, and it was the first time I encountered extreme high temperature and drought last year.” Ge Youliang, a senior agronomist at Tonglu County Agricultural Technology Promotion Center, said that as a science and technology commissioner, guiding fruit farmers’ production is his main job. Not optimistic.

He told reporters that usually after July, peaches, kiwis, plums and other fruits enter the ripening period, and many fruit farmers are looking forward to a bumper harvest. However, the unstoppable scorching sun last summer caused many fruits to suffer from “sunburn”, which had a great impact on the quality of the fruits and directly affected the market.

Zhou Weijun, a professor at the Agricultural College of Zhejiang University, believes that in the context of global warming, in addition to the frequent occurrence of extremely hot weather in summer, the probability of warm winters in the future will also increase. But that doesn’t mean the crops will survive the winter. On the contrary, the warmer the winter, the greater the temperature fluctuation, and the more prone to freezing damage.

Take rape as an example. At present, winter rape is mainly planted in our province. “Carrying” low temperature is the only way for its growth. When the temperature rises, flower buds will bloom. “Once it blooms, the low temperature resistance of rapeseed will be greatly weakened. If there is another low temperature process, it will easily cause frost damage.” Zhou Weijun said.

Ge Youliang agreed with this judgment: “In recent years, the temperature in winter has fluctuated greatly. In the past winter, strong cold air and cold waves came several times, which damaged many loquat and citrus trees and caused losses to fruit farmers. .”

The effects of extreme weather are not limited to agriculture, and are disrupting energy supplies. Once extreme heat or extreme cold weather occurs, it will lead to a surge in electricity demand.

For example, last year’s extreme high temperature weather led to a sharp increase in the electricity consumption demand of residents in many parts of the country, which caused a huge impact on the power system.

In Zhejiang, residential electricity consumption in July and August 2022 will increase by 41.24% and 57.72% year-on-year respectively. On July 11, the province’s highest electricity load reached 101.9 million kilowatts, a record high. In Sichuan, a major hydropower province, the dry weather has caused a sharp drop in hydropower production capacity, forming a power gap. Coupled with the peak power consumption period in summer, it has fallen into a rare “power shortage”.

In addition, extreme weather such as torrential rain and freezing temperatures also tested the resilience of transportation. “Railways and highways are ground transportation methods, which are easily affected by weather and geological disasters. In the face of extreme weather, there have also been traffic interruptions and other phenomena, which have affected the normal operation of the economy and society.” Lei Yuan told reporters. For example, in early 2008, The southern part of my country encountered rare low-temperature, rainy, snowy and freezing weather. At that time, many traffic arteries were interrupted, which brought great challenges to the transportation and supply of products in the market.

In the current highly interconnected social and economic system, local climate anomalies may affect the whole body, resulting in cross-industry and cross-regional chain reactions, directly affecting the normal operation of various industries.