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How extreme weather affects our lives

With global warming, the occurrence of extreme weather and climate events shows an increasing trend. After global warming, the distribution of energy in the atmosphere will change, such as increased evaporation and faster water circulation, resulting in more extreme events. Take drought and flood as an example. After the climate warms, the temperature of land and ocean surface will increase, evaporation and transpiration are more likely to occur, and the moisture that can be held in the atmosphere will also increase. This means that to achieve precipitation conditions, more water vapor is required. If the water vapor in the atmosphere is not saturated, then the atmosphere will continue to absorb water, making the land drier and forming a drought. Once the saturation state is reached, due to the increase of atmospheric water content, it is easy to form heavy precipitation, which may lead to flood disasters. In addition, due to the enhanced exchange of heat and water vapor between the northern and southern hemispheres, the climate is more likely to become abnormal.

The planet is heating up, opening a “Pandora’s Box” of extreme weather. The emergence of more and more extreme weather and climate events will have an impact on economic and social development and threaten the safety of people’s lives and properties.

Rachel Kate, Vice President of the World Bank, said: “The first decade of the 21st century saw increasing global economic losses—from an average of $50 billion a year in the 1980s to an average of $200 billion a year in recent years. Three-quarters of these are caused by extreme weather. From 2001 to 2006, climate disasters caused an average loss of 1% of their gross domestic product (GDP) in rapidly developing developing countries, reaching the More than ten times the national average.”

The report “Counting the Costs in 2020: A Year of Climate Crash” lists 15 catastrophic events caused by extreme climates that occurred in 2020, such as Australian wildfires, East Africa locust plagues, and Indian floods. These representative events have been logarithmic. Disastrous effects on the lives of millions of people. Among them, the wildfire that swept about 20% of Australia’s land not only caused the displacement of tens of thousands of people, but also caused 100,000 wild animals to suffer. At least 34 species were extinct in the wildfire, and various losses were conservatively estimated at 50 One hundred million U.S. dollars. The frequent occurrence of hurricanes has brought direct losses to the Central American region of more than 40 billion US dollars. In addition, the five floods in Asia in 2020 have direct losses of US$62.5 billion.

According to the British “Guardian” report, the climate crisis has intensified, and people may no longer drink tea of ​​the same quality as before. Some of the world’s largest tea-growing regions will be some of the worst affected by extreme weather. If climate concerns continue at their current pace, yields in these growing areas are likely to plummet in the coming decades.

The increasingly severe global climate crisis has had a negative impact on the international community, the most serious of which is the food security problem caused by climate change.

Agriculture is a “sensitive and fragile” industry, and any changes in nature will affect agricultural production, which makes climate security and food security in the “same security body”. Specifically, the impact of climate change on food security is mainly manifested in the following three aspects.

First, in terms of food supply, the frequent occurrence of extreme weather has reduced food production and reduced the amount of food circulating in the international market. The frequent occurrence of droughts caused by global warming not only leads to an increasing shortage of water for agricultural irrigation, but also reduces the water content of the soil layer due to the accelerated evaporation of water, thus destroying the soil fertility. The outbreak of sandstorms and floods will cause serious erosion of cultivated land, aggravate land salinization, and cause crops to wither or food quality to decline. According to a report jointly released by the Food and Agriculture Organization of the United Nations and the World Food Program in July 2020, most of the 25 countries in the world that are in the early warning of food crisis are affected by extreme weather such as floods and droughts. For example, Afghanistan’s 2020 wheat production is expected to be nearly halved due to drought.

At the same time, climate change will cause imbalances in agricultural ecosystems and easily induce secondary crises such as insect pests. For example, the drought-induced locust plague from 2019 to 2020 severely hit the food production in East Africa, West Asia, South Asia and other regions. Among them, more than one million hectares of land in East Africa was infested by locusts, and some crops in Pakistan, India and other countries were damaged. In addition, out of the need to ensure their own food security, when grain harvests fail, food-producing countries often adopt austerity food policies, which threatens the integrity of the global food supply chain.

Second, in terms of food access, climate change weakens the economic foundation of disadvantaged groups such as farmers and women, resulting in a decline in their food purchasing power. To judge whether a country’s food security is not enough, it is far from enough to only examine the supply side, but also need to pay attention to the acquisition side. Because, even if there is an ample global supply of food, if people do not have access to it, it will still be considered food insecure. Consecutive droughts or catastrophic floods can easily destroy a year’s cultivation of farmers. Without food available for export, their economic income will be damaged, thereby reducing their ability to improve their nutritional status by diversifying their food purchases.

Finally, at the food use level, increased carbon dioxide levels and water quality damage lead to reduced crop quality, which will reduce the protein, mineral and vitamin content of rice, creating potential public health concerns. Secondary disasters caused by climate change can also bring germs into fields and induce foodborne diseases. In rural areas lacking advanced grain storage facilities, the occurrence of droughts, floods and other disasters aggravated local grain losses and weakened the ability to self-supply grains after disasters.

Therefore, the “State of the World’s Food Security and Nutrition in 2021” report jointly released by the Food and Agriculture Organization of the United Nations, the World Food Programme and the International Fund for Agricultural Development and other United Nations agencies regards climate change as one of the important factors that induce the global food crisis. It is believed that the frequent occurrence of climate disasters has made it more difficult for the international community to achieve the goal of “zero hunger” by 2030. At present, the world should strengthen cooperation and enhance the resilience of the global food system to natural disasters. At the same time, all countries should consider climate and food in the same system, build an all-round safety network, and make overall plans to build a green, hunger-free and sustainable global village.

Grain Storage Facility

In early 2022, a study published in the Proceedings of the National Academy of Sciences showed that some severe weather events cause people to experience accelerated aging.

The conclusion that extreme weather accelerates aging comes from a long-term study of human relatives, the macaques. In 2017, this group of monkeys living on Santiago Island experienced Category 4 Hurricane Maria. Although most of the monkeys survived the disaster, 2.75% of the monkeys died. The researchers drew blood from the survivors and did a comprehensive genetic analysis.

The results showed that the extreme weather event in 2017 accelerated the aging of macaques at the molecular level. After the hurricane, 4% of their immune cells had altered gene expression—inflammation genes were significantly elevated, and genes related to protein translation, protein folding, and immune responses were suppressed. Among them, expression of one called a “heat shock gene” was the most suppressed, with a two-fold decrease in activity. Such genes not only promote the proper functioning of protein production in cells, but are also linked to cardiovascular disease and Alzheimer’s disease. Changes in the expression of these genes closely resemble the natural aging process. The macaques were, on average, 2 years older (roughly equivalent to 7-8 years in humans) compared to their counterparts who had not experienced the “big winds and waves”, the researchers said.

A group of macaques sit together and groom after a hurricane

Aging comes from stress. The researchers speculate that the destruction of the living environment by extreme weather and the plundering of the lives of relatives and friends may have made these once unfettered monkeys feel the sudden pressure. Their inner panic and anxiety continued to expand, and the immune system also paid a corresponding price, so they “whitened their heads overnight.” Could a similar fate happen to humans? The researchers couldn’t help but worry about this. After all, macaques and humans have certain similarities in physiological and behavioral characteristics, and humans have even more “weather anxiety” levels. After record-breaking heat in British Columbia, Canada, in 2021, researchers from the Alliance for Mental Health and Climate Change found that local residents’ anxiety levels about weather events increased by an average of about 13 percent. In 2019, a survey by the University of York showed that more than half of England’s residents were “unhappy” after experiencing floods.

Property damage and traffic congestion caused by weather factors have led to a large area of ​​”psychological trauma”. While everyone ages, not everyone ages at the same rate. A negative experience—such as experiencing extreme weather and climate events—is likely to lead to chronic inflammation that predisposes to the onset of some diseases of aging.

Global warming has made the climate more unstable. Extreme cold and warm events occur frequently and their intensity has increased or has become the new normal, especially large-scale extreme weather events, which have a serious impact on life and production. In this regard, on the one hand, we should actively promote the “dual carbon” action to control global warming; on the other hand, it is predicted that at least until the middle of the 21st century, the climate will continue to warm, facing unavoidable extremes With the increasing trend of weather and climate events, it is urgent to strengthen deployment and response in preventing extreme weather and climate events.

Extreme weather is generally divided into four categories, namely extreme high temperature, extreme low temperature, extreme drought and extreme precipitation, all of which are short-lived but intense meteorological events. Its general characteristics are that the probability of occurrence is small and the social impact is large.

Among them, extreme high temperature weather is characterized by continuous temperature rise for several consecutive days. Take 2013 as an example, the northern hemisphere experienced many extreme high temperature weather in this year. For example, in early and mid-July, the United Kingdom was hit by a continuous heat wave, which killed at least 760 people due to the extreme heat.

The characteristics of extreme low temperature weather are opposite to those of high temperature. Whenever extreme low temperature weather occurs, the local temperature will mostly drop to minus tens of degrees Celsius. Extreme low temperature weather is often accompanied by cold waves. If the local temperature drops by 14°C or more within 48 hours, it is a cold wave standard, which also proves that extremely low temperature weather has occurred in the local area.

The criteria for extreme dry weather require some other conditions to be met. For example, extreme dry weather occurs when the local precipitation drops sharply over a period of time, and the water content of the soil layer is much lower than the average of several years. Extremely dry weather has more serious consequences than extreme high temperature weather, because whenever extreme dry weather occurs, it proves that there has been no rainfall in the local area for several months, which will indirectly lead to reduced harvests or even no harvest.

Extreme precipitation weather is characterized by continuity. The extreme precipitation weather is generally the daily precipitation intensity is high, and the continuous time is more than 3 days. Extreme precipitation also has its own indicators, such as comparing the longest precipitation time of each local month, taking an average, and finally comparing the average with the precipitation time of this time, and exceeding it is extreme precipitation weather.

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