High -temperature weather exceeding the limit of life has appeared, but this is just the beginning

Summer is becoming more and more difficult.

Since mid -June this year, extreme high temperatures have continued to appear, and the temperature in different cities across the country has brushed the highest record of the same time in previous years. Especially since the summer, cities with the highest temperature exceeding 40 ° C have frequently appeared. High temperatures not only appeared in China, but also looked at the northern hemisphere. The United States burned continuous forest fires and 510 people died of high temperature weather within a week. At the same time, Finland and Norway, near the Arctic Circle, also surpassed nearly 34 ° C.

What step is the "fever" of the earth? Is there any solution for scientists? Will our descendants still see the summer of breeze, as we are full of sweet memories of summer?

The extreme high temperature that human beings can withstand have appeared

First of all, the earth has indeed been fever in recent years. For humans, the earth has become increasingly inaccurate.

Studies have shown that high -temperature weather that can bear the scope of humans has begun to appear [1]. However, the temperature that measures the "human limit" is not the temperature that everyone gets in the weather forecast (the temperature of the air in the shuttle of the shutters at a height of 1.5 meters), but the temperature of the wet ball.

Although the temperature is high at 47 degrees, it cannot directly describe the changes in the human body at this temperature

Compared with the temperature, the temperature of the wet ball is more associated with the human life signs.

The definition of wet ball temperature refers to the temperature reached by the air that is humidified by a piece of air. In other words, the current environment can only reach the minimum temperature that the current environment can only reach by evaporating water. Therefore, the temperature of the wet ball is closely related to the relative humidity.

The normal body temperature of a person is about 37 ° C, and the skin temperature is maintained at about 35 ° C. In high temperature environments, the human body will mainly regulate the body temperature by sweating, but when the humidity of the environment is high, the heat dissipation pathway is blocked, and the person will feel "sultry". The human body's own cooling function has a certain threshold. When the temperature of the wet ball reaches 35 ° C, even healthy people cannot heat dissipation normally, which causes great health risks due to the rise in core temperature and even cause death. [2]

Research in 2020 shows that in some subtropical coastal areas, the temperature of the wet ball has reached 35 ° C, and the frequency of this extremely humid weather has doubled in nearly forty years [1], and scientists It was originally believed that this situation would occur at least after decades.

High temperatures that have recently appeared in Zhejiang, Fujian and Guangdong are usually accompanied by high humidity. At the same time, the temperature reaches 40 ° C. It is also accompanied by a relative humidity of 60%, or the temperature reaches 36 ° C and is accompanied by 80%relative relative relatives humidity. In this case, the temperature of the wet ball has reached 33 ° C, which is very close to the wet ball temperature of the dead. It is very dangerous to carry out any outdoor activities in such an environment for a long time. This is why outdoor workers fainted at high temperatures due to thermal ejaculation at that time.

Different relative humidity and temperature conditions corresponding to the wet ball temperature (the wet ball temperature is calculated based on Stull (2011) [3]) ｜ Self -making

In fact, the heat waves that swept the world this summer came to India and Pakistan as early as March, bringing the hottest March in 1901 (the highest temperature exceeds 40 ° C). Since May, the United States, Europe, and China have also been attacked by heat waves.

The fundamental cause of climate change caused by global warming is the main cause of this phenomenon. In the past sixty years (1960 ~ 2018), the highest regional high -temperature events in China occurred in the summer of 2003, 2013 and 2017, respectively. In 2013, it was the most (high temperature, last long) [4] Essence Some studies have pointed out that the extreme level of heat waves (temperature, continuous days, scope of influence) and the trend of global warming are almost linearly increased. The frequency of heat wave high -temperature events brought by the global warming 2 ° C (before the era of industrialization) will be worse than the global. The heating of 1.5 ° C is doubled [4].

If humans cannot slow down the speed of global warming, in the visible future, summer will become hotter and more and more "invincible".

Extreme climate, high temperature is just the first step

The continuous high temperature directly tests human adaptability.

In addition to bringing a physiological risk, a review article based on global past studies shows that high temperatures can also have a negative impact on people's mental health [6]. Researchers have found that when the heat wave comes, every temperature increases by 1 ° C, the incidence of disease -related diseases will increase by 0.9%, and the mortality will increase by 2.2%. Due to the relatively lack of sufficient refrigeration conditions in low -income groups, the risk of mental illness caused by high temperature will be higher.

The impact of continuous high temperature on agriculture cannot be ignored. Long -term drought and high temperature can affect the growth of crops and cause insect disasters. In order to ensure the harvest, the superposition effects of various factors will make the prices of food, vegetables and fruits continue to rise for a long time. This is undoubtedly worse for the poor.

In the face of extreme high -temperature weather, the demand for refrigeration has increased rapidly, and humans will consume more energy. The proportion of clean energy itself is limited, and high temperature and drought have blocked wind and hydropower. Human beings can only burn more fossil fuels, which will further exacerbate the emissions of greenhouse gases. This vicious cycle will exacerbate global warming and become hotter in summer.

Extreme high temperature is our most intuitive feeling of climate change, but what really threatens the survival of human population is the secondary disaster caused by climate change. Extreme high temperature is usually accompanied by drought, causing forest fires worldwide. Not only causes severe local air pollution, a large number of residents are forced to evacuate, but also severely damage the forest ecosystem that humans depend on survival. Extremely high temperatures are likely to occur in super heavy rainfall, which leads to flood disasters.

According to statistics [7], in southern, northwest and northeast, this composite flood and heat wave sequences increased by five to ten times after 2000. In the densely populated Yangtze River Huaihe River Basin, the frequency of floods related to typhoons and the occurrence of typhoons has increased by ten times as much as ten times. This continuous extreme weather has increased the difficulty of post -disaster rescue and reconstruction while causing casualties and economic losses.

Although China has no fatal heat waves at present, climate change is faster than expected. According to a research report released by McKinsey in 2020, by 2030, China may have 10 million to 45 million people facing the threat of extreme high temperature and fatal heat waves. By 2050, this number may climb to 110 million to 250 million. [8].

What are scientists doing?

Faced with the arrival climate challenges, scientists are fighting for the reasons and solutions for global warming.

For about six years, the UN subordinate of the IPCC (Special Committee of the Intergovernmental Climate Change) of the United Nations will convene thousands of scientists around the world to organize and review the scientific documents published during the period and write reports. The sixth IPCC report released this year shows that [9], the impact of human activities has significantly caused the temperature of the atmosphere, the ocean and land surface to rise, and the rate of warming is unprecedented in the past two thousand years.

Since 1950, extreme high -temperature weather (including heat waves) in most land areas has become more frequent and fierce. The main factors that cause the earth's warming are greenhouse gas emissions led by carbon dioxide and methane. For the picture of the sustainable development of human beings, we must first try to reduce the rate of earth warming by reducing emissions.

The history of global temperature changes and the reasons for recent warming. (A) Global surface temperature changes rebuilt from the climate archives (B) The changes in global surface temperatures in the past 170 ｜ IPCC, 2021: Summary for Policymakers

According to the model prediction [10], if humans want to control the earth's heating within 2 ° C, global greenhouse gas emissions need to reach the peak between 2020 and 2025 (latest). The report of the third working group of IPCC shows [10], from 2010 to 2019, the total amount of net emissions of human greenhouse gas continued to rise, with an average emissions higher than that of any previous ten years, although its emission growth rate was lower than the previous ten years ( 2000-2009).

Under the climate challenges that are approaching, countries have also begun to take emergency measures to survive the bitter summer. On August 1, in order to save energy, the temperature soared to 47 ° C at the temperature, and the government required the air conditioner temperature of enterprises, restaurants, museums and other places to not be less than 27 degrees Celsius. When opening the air conditioner, the doors and windows were closed. Guangdong, one of the hottest provinces in the summer, also stipulates that when the highest temperature of the day is above 39 ° C, the open -air work should be stopped on the same day. At the same time, some countries are trying to establish a "sponge city" that adapt to extreme climate. By increasing measures such as raising green space and using water -transmitting paving, it can better cope with the extreme heavy precipitation brought by global warming.

However, these measures are only a suitable measures adopted by humans to maintain daily life under climate change. To slow down the speed of global warming, all human beings need the wisdom, consensus, and cooperation of all mankind. This is not a simple matter, but it is the most important thing for our species. Because for the earth, there is no difference between humans and bacteria, birds, and trees. Even if the temperature continues to rise, the tsunami swallows coastal cities, the earth will continue, and only ourselves who really hover at the juncture of survival.

references

[1] Raymond, color, tom matthews, and radley m. horton. "The emergence of heat and humidity too for human tolerance." Science Advances 6.19: EAAW1838..

[2] Sch cr, C. The Word Heat Waves to CLIM Change 6, 128–129 (2016). Https://doi.org/10.1038/nclmate2864

[3]Stull, Roland. "Wet-bulb temperature from relative humidity and air temperature." Journal of applied meteorology and climatology 50.11 (2011): 2267-2269.[4]Wang, Jun, and Zhongwei Yan. "Rapid rises in The Magnitude and Risk of Extreme Regional Heat Wave Events in China. "Weather and Climate Extremes 34 (2021).

[5] Sun, Y., Hu, T., ZHANG, X. (2018). Substantial Increase in Heat Wave Risks in CHINA in A Future Warmer World. Earth's Future, 6 (11), 1528-1538.

[6]Liu, Jingwen, Blesson M. Varghese, Alana Hansen, Jianjun Xiang, Ying Zhang, Keith Dear, Michelle Gourley et al. "Is there an association between hot weather and poor mental health outcomes? A systematic review and meta-analysis . "ENVIRONMENT International 153 (2021): 106533.

[7] Chen, Y., Liao, Z., shi, y., tian, y., zhai, p. (2021). Detectable Increases in Sequential Flood-Heatware Events China During 1961–2018. 48, e2021GL092549. Https://doi.org/10.1029/2021gl092549

[8] McKinsey Global Research Institute (MGI). Climate Risk and Response: PHYSICAL Hazards and Socioeconomic IMPACTS [EB/OL]. [2020-06-12] .https: //www.mckinsey.cn/ : Chinese countermeasure

[9]IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai , A. Pirani, S.L. Connors, C. Péan, S. Berger, N. CAUD, Y. Chen, L. Goldfarb, M.I. GOMIS, M. Huang, K. Leitzell, E.B.R. Matthews, T.K. MayCock, T . Waterfield, O. Yelekçi, R. Yu, and B. ZHOU (EDS.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, PP. 3−32, DOI: 10.1017/97881009100910091009100910091009100910091009100910091009100910091009100910091009100910091009100910091009100910091009100910091009100910091009100910091009191

, A. Al Khourdaie, R. Van Diemen, D. MCCollum, M. Pathak, S. SOME, P. Vyas, R. Fradera, M. Belkacemi, A. Hasija, G. Lisboa, S. Malley, J. Malleyy(EDS.)]. Cambridge University Press, Cambridge, Uk and New York, NY, USA. Doi: 10.1017/978157926.001 Author: Judy

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