How big is the impact of climate change

The impact of climate warming on mankind and the planet is huge and far-reaching. Climate warming has caused sea levels to rise, and ocean heat waves have become more frequent and severe. Some animal and plant communities may be forced to migrate due to the inability to adapt to the speed of global warming, and even cause the disappearance of many species. Global warming will also increase the frequency of natural disasters such as high temperatures, heat waves, tropical storms, and tornadoes. Climate warming is still a major factor endangering human health. Some diseases currently mainly occurring in tropical regions may spread to mid-latitudes as the climate warms.

Climate change and “extraordinary drought”
The sandstorm in the 1930s was one of the most serious environmental disasters of the last century. Violent dust storms ruthlessly hit the Great Plains of the southern United States, causing severe ecological damage and forcing 2.5 million people to leave the area. The resulting “dust pneumonia” claimed countless lives. Studies have shown that this disaster was caused by severe drought of the land and over-cultivation by people.

Today, climate change driven by human activities is exacerbating the occurrence of droughts in many regions around the world. It is now clear that short-term and long-term exposure to particulate matter (including sand and dust) in the air poses a major health risk.

“Sand dust” refers to air particles derived from soil generated by wind erosion or human activities. Any soil particle smaller than 0.05 mm (roughly equivalent to the diameter of a human hair) may rise into the air, but the main cause of health concerns is that it is smaller than 0.0025mm (2.5 microns) particles, these particles are collectively referred to as “fine particles (PM2.5)”. These particles stay in the air for a long time and are the most harmful to human health because they can penetrate deep into the lungs.

The particulates in the air mainly come from the combustion of fossil fuels and emissions from other industrial sources, but there is evidence that sand and dust are also an important source. For example, silica, which accounts for 60% of dust storms, is known to cause chronic lung inflammation, lung cancer and autoimmune diseases. At the same time, sand and dust can spread pathogens and toxic pollutants carried by the soil in a large area.

By the end of this century, the level of fine sand and dust in the southwestern United States may increase by 30% than it is now, leading to a 130% increase in the number of premature deaths and a 300% increase in the number of people hospitalized due to sand and dust exposure. Even under the most effective climate mitigation program, it is predicted that the level of fine sand and dust in the area may increase by 10%. The number of premature deaths and hospitalizations due to fine sand dust exposure increased by 20% and 60%, respectively.

Of course, similar situations exist in other parts of the world. For example, studies have shown that the occurrence of sandstorms in China and Saudi Arabia is affected by rainfall or soil moisture in surrounding areas (including remote deserts and drylands).

Today, the world’s drylands account for 41% of the world’s total land area and live about 2.1 billion people. According to the world’s current greenhouse gas emission trajectory, droughts in parts of South America, Africa, Australia and the Mediterranean will intensify, and drylands will further expand. Studies have shown that climate change may lead to the deterioration of air quality in many densely populated arid regions around the world, which is one of the many threats climate change poses to human health and well-being.

Ocean heat waves endanger human society and natural ecology
Over the past few decades, ocean heat waves have appeared more and more frequently around the world. Scientists predict that climate change will make heat waves more common and lasting, and will cause damage to vulnerable aquatic species and fisheries surrounding marine ecosystems. But there is no reliable way to predict when they will happen and what measures we can take to reduce the damage. At present, oceanographers are trying to reveal the driving forces that cause ocean heat waves so that they can be predicted and the ecological and economic losses caused by them can be minimized.

The intensity and frequency of ocean heat waves are unprecedented. An ocean heat wave named “Blob” lasted for 3 years. This is the longest ocean heat wave on record. In 2015, the Tasman Sea heat wave lasted for more than 8 months, resulting in a large number of abalone and oyster deaths; in 2012, the heat wave near the east coast of Canada and the United States pushed the lobster northward; the ocean heat wave in 2011 uprooted the seaweed and uprooted the seaweed. Sharks and other fish have driven off the waters of Western Australia; earlier in 2003, the Mediterranean heat wave also caused great harm to marine life.

In 2011, the ocean heat wave near Western Australia reduced local blue crab catches by more than 90%, resulting in a suspension of fishery production to allow the species to recover.

As the amount of sunlight reaching the polar bottom increases, fan-shaped worms (blue-green) and sponges (orange) may disappear.

Eric Oliver, assistant professor of oceanography in Canada, believes that heat waves are a natural part of the ocean system. Seawater is sometimes warmer, sometimes colder, and sometimes very warm or very cold. However, greenhouse gas emissions have increased the global average temperature, causing ocean heat waves to occur more and more frequently, and large areas of seawater have been pushed to unprecedented high temperatures. However, it is difficult for marine ecosystems to adapt to this change. Marine organisms may be able to survive the continuous rise in water temperature, but sudden ocean heat waves may push them to the brink of death.

In 2011, the heat wave caused the death of blue crabs in Shark Bay, Western Australia. For this reason, the local government closed the blue crab fishing activities for a year and a half to facilitate the recovery of the species. But not all marine life are so lucky, and the abalone affected by the ocean heat wave has not recovered so far.

If we can predict the specific time and location of the heat wave, then aquaculture farmers, fishermen and wildlife managers will have a better opportunity to save money and save species: seafood farmers can temporarily postpone the stocking of vulnerable species in aquaculture facilities, legislation Workers can issue seasonal fishing bans or temporarily expand protected areas, and scientists can take measures to protect marine life or preserve the seeds of fragile marine plants. In 2014, Thomas Warnberger, Associate Professor of Marine Ecology at the University of Western Australia, convened scientists from many disciplines to study these extreme events, and at an international conference for this purpose, he formulated the naming and definition of ocean heat waves, tracking their locations, and An agreement to evaluate its ecological and socio-economic impact.

Scientists all over the world are trying to understand what caused the extreme warming of the sea. Oliver is such a scientist. He inputs ocean data collected by scientists, satellites, buoys, and deep-sea robots into computer modeling software to identify the forces driving ocean heat waves. This is a relatively new research field, and there is no clear research result yet. Oliver believes that past heat waves can be roughly divided into heat waves driven by the ocean and heat waves driven by the atmosphere.

Take ocean-driven heat waves as an example. The Tasman Sea heat wave that occurred in 2015 is one of the more typical events. The ocean current flowing south along the east coast of Australia usually turns to New Zealand, but in 2015, it suddenly rushed westward towards Tasmania, bringing a warm current from the tropics that lasted for more than six months. Oliver said: “People even saw tropical fish in the water.”

According to Dillon Amaya, a climate scientist at the University of Colorado at Boulder, the heat wave in the Pacific in 2019, the so-called “Blob 2.0”, was brought down by the atmosphere. Using a computer model, he found that when the wind over the Pacific weakened, a heat wave appeared. Wind can cool the sea, just as wind can evaporate sweat, so the stagnant air over the Pacific will lock more solar heat in the water. The recent “Blob 2.0” heat wave is somewhat similar to the “Blob” heat wave. “Blob” has caused great harm to marine life from Mexico to Alaska in three years.

On July 21, 2012, a large sandstorm swept across Phoenix, the United States.

To this end, Dillon Amaya and other researchers have established a computer model to simulate heat waves to simulate the complex process of ocean and atmospheric currents, sea surface temperature and salinity changes, and lay the foundation for predicting future ocean heat wave events. This will help predict the time of the next heat wave. Frequent ocean heat waves have sounded the climate police, and people are trying to cope with it and adapt to it.

More harm from climate warming
There are many more harms to natural ecology and humans caused by global warming. From bacteria to volcanoes, from micro to macro, from natural ecology to human health, all have been severely affected by climate change.

Global warming has led to the death of large areas of desert bacteria and accelerated the process of global desertification. Nowadays, tourists who come to arid regions usually first see a desert zone with almost no life. However, in these deserts, special communities composed of lichens, algae, moss, fungi and cyanobacteria are usually found, which are called “cryptic soil” or “soil crust”. These organisms bind the loose desert soil together, helping to maintain life-sustaining water.

The soil in the desert looks desolate and lifeless, but in fact it is full of bacteria. Bacterial colonies can grow very thick to form a solid “biological crust”, or biological rust, which stabilizes the soil from erosion.

A study of biological rust bacteria in American deserts showed that different types of desert bacteria thrive under different temperature conditions. Some prefer the intense heat of Arizona and New Mexico, while others are in southern Oregon and Utah. Survive better in cooler climatic conditions. As the global climate changes, the temperature becomes more and more unstable, and it may be difficult for desert bacteria to adapt, and desert soil is therefore more vulnerable to erosion.

A new study found that global warming has led to an increase in the number of volcanic eruptions. As glaciers melt into the ocean and global sea levels rise with climate change, the weight distribution on the earth’s crust will shift from land to ocean. Some studies have shown that this change in weight distribution may cause volcanic eruptions to become more frequent. Researchers have found evidence of correlation in the rock record. In several periods of the earth’s history, the remains of a large number of volcanic eruptions are related to the period of glacier melting. Of course, human beings in the 21st century may not experience this kind of transformation, and this kind of influence seems to lag about 2500 years.

In addition, the warming of the sea will also cause a surge in the number of dark-loving crown jellyfish. In some areas, precipitation increased, and river fluidity increased. The stronger currents stirred up more silt and debris, which eventually flowed into the ocean, making the ocean more opaque. In recent decades, as precipitation has increased and snow has melted, the sea waters along the coast of Norway have become deeper and darker. Some researchers speculate that this tendency of the ocean to become darker is the main cause of changes in regional ecosystems, including the surge in jellyfish populations.

As the sea ice melts, more sunlight will pour into the shallow waters near the poles. Every summer, seabed biomes such as worms, sponges and other invertebrates that are accustomed to living in the dark will experience longer periods of sun exposure. The latest research shows that increased sunlight penetration leads to the prosperity of seagrass and other marine plants, causing a large number of marine life to suffocate due to lack of oxygen, and quietly changing the status quo of marine biological communities. This phenomenon of shifting from an invertebrate-based community to an algae-based community has been found in some parts of the Arctic and Antarctic coastlines, which may greatly reduce the biodiversity in these areas.

Fine dust particles much thinner than human hair

In addition, a large number of studies have shown that climate change is not only harmful to the natural ecology, but also endangering human health. A recent study found that high temperature and ozone may cause deterioration of people’s heart health. The results of the study show that the summer high temperature in American cities is related to a decrease in human heart rate variability, and low heart rate variability is related to an increased risk of death from heart attack.

Due to the early arrival of spring due to global warming, allergic pollen will spread earlier in the year, and the number of people allergic to pollen worldwide is increasing every year. Part of the reason for the rising trend of human allergies in recent years may be due to rising carbon dioxide levels and rising temperatures. Due to climate warming, the flowering period of plants is earlier, the total amount of pollen increases, and people’s sensitivity to pollen is also increasing. Some temperature and precipitation models show that by 2040, the global pollen content may more than double. Although genetic factors play a big role in allergies, longer flowering seasons and denser pollen may aggravate the symptoms of allergy sufferers.

At the same time, global desertification will also promote the growth of harmful bacteria in the ocean. Studies have found that desert dust promotes the growth of Vibrio bacteria in the ocean, which can cause gastroenteritis and other infectious diseases in humans. Researcher Irene Lip of the University of Georgia in the United States found that within 24 hours of mixing sand and dust from the Moroccan weathered desert with seawater samples, the number of vibrio bacteria increased 10-1000 times. Among them, one kind of Vibrio may cause infections of open wounds of the eyes and ears, while the other kind of Vibrio may cause cholera. This increase in the number of bacteria may mean that more people are getting sick from exposure to contaminated seafood.

In addition, global climate change will accelerate the scope and speed of disease transmission. Certain insects that transmit pathogenic factors are greatly affected by weather changes and rising temperatures. Because these disease vectors are cold-blooded animals, they need to rely on the surrounding environment to control their body heat. Rising temperatures may help these insects to prevent malaria and other certain diseases. Some infectious diseases spread to new areas. Increased rainfall is also beneficial to insects. Some studies have linked increased rainfall to disease outbreaks, especially water-borne diseases.