Climate change is a reality and it affects us all

31 March 2022 | Ophelie Langlois

The evidence of climate change is overwhelming: rising global temperatures, melting of glaciers and Arctic Sea ice, rising sea levels, increasing occurrence of extreme weather events. Greenhouse gases generated by humanity are altering our climate with an alarming speed. Decades of research have proven this fact, bringing domain experts to near unanimity. Despite the increase in awareness of the general public regarding this subject, still approximately a third of Americans do not believe in the reality of the situation or do not worry about it, nor accept our responsibility 1

Climate change has an impact on humanity in many different ways, affecting human health, food production and generally all ecosystems but, ironically, it is the direct or indirect consequence of our modern lifestyle. Since the Industrial Revolution, human activities have increased greenhouse gas concentrations in an unprecedented manner, which is the main factor contributing to the current global warming 2

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Vietnam is in the top 10 countries most affected by climate change. Within Vietnam, significant volumes of agricultural waste are burnt, which negatively impacts the environment and health.  However, the conversion of rice straw in the production of chemicals (traditionally made from fossil fuels) can contribute to greenhouse gas reduction, reduce health and societal burdens associated with burning and provide a new economic stream for local communities.

In this post, we will explain the processes leading to climate change. We will uncover the consequences of uncontrolled greenhouse gas production and global warming on the environment and human health, to understand why it is important to act against it now. Vietnam will be used as a study case to understand how local climate is affected by climate change.

Climate change explained

How natural climate changes work

Sunlight has two fates when it arrives on Earth: the energy coming from the Sun is either reflected back to space by bright surfaces such as ice and clouds or absorbed by the surface and the atmosphere. The absorbed energy, for the most part, is then converted into heat and either trapped in the atmosphere or radiated back into space. This balance between incoming and outgoing energy is fragile and any disturbance can affect the climate. Past climate changes, occurring approximately every 100,000 years and due to changes in Earth’s orbit, led to the extinction of many species, population migrations, and modification of lands and ocean circulation. Variations of the Sun’s output and Earth’s orbit around the Sun, volcanic eruptions, and fluctuations in the climate system such as El Niño and La Niña (the tropical Pacific swings between warm El Niño and cooler La Niña events on timescales of two to seven years, causing temperature changes and rainfall patterns) are natural events playing a role in modifying climate. They are, however, not sufficient to explain the current climate change, which is much faster than previous ones and mainly attributed to the increase in concentrations of greenhouse gases 2

 

Human activities are a major contributor to climate change

The atmosphere is roughly composed of 78% nitrogen, 21% oxygen and 1% argon but also of other gases in smaller amounts, including greenhouse gases such as water vapor, CO2, methane, and nitrous oxide. Greenhouse gases are able to absorb heat and re-emit it in all directions, preventing it from escaping into space and trapping it in the atmosphere. Increasing their concentration ultimately leads to warming of the Earth’s surface air and human activities have drastically increased the amount of atmospheric greenhouse gases in the past 200 years. Fossil fuel burning, deforestation and land use changes are processes releasing CO2. They disturb the balance of the carbon cycle because natural processes (storage or use of carbon by nature), which normally restore the balance, are too slow to compensate the CO2 release rate 2.  Currently, it is estimated that human activities release 10 billion tons of carbon every year into the atmosphere and that is not even considering land use changes. This number is colossal, and that needs to change.

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Comparison of heat redistribution between natural and human-enhanced greenhouse effects.

How are climate variations regulated?

Certainly, processes regulating the climate are complex and global warming is modulated by – but not exclusively – volcanic eruptions and ocean circulation. and feedbacks from the initial warming that can either amplify or diminish it.

  • Volcanic eruptions increase the number of small particles in the air, which reflect sunlight, leading to short-term cooling.

  • The Ocean is a heat reservoir where variations in the water circulation can result in fluctuations in surface and deep-sea temperatures.

  • A warmer atmosphere contains more water vapor, a greenhouse gas that causes further warming.

  • The reduction of ice surfaces through melting is exposing darker ocean and land surfaces which absorb more heat, causing further warming.

  • Warming of the atmosphere modifies cloud coverage, which amplifies or dampen temperature change 2-4.

    Examples of processes that influence climate change.

    Natural Causes Human Causes
    1. Axial tilt 7. Burning of fossil fuels
    2. Variation of Earth's rotational axis & orbit around the Sun 8. Deforestations
    3. Solar eruptions 9. Livestock production & Agriculture
    4. Volcanic eruptions 10. Industrial gases
    5. Ocean current 11. Food waste
    6. El Niño & La Niña 12. Other pollutants (e.g. transports)

The (undeniable) evidence that climate change is triggered by human activities

Since the Industrial Revolution, human activities have increased greenhouse gas concentrations immensely. Atmospheric CO2 has increased by more than 40%, mostly since 1970. This was directly measured in the atmosphere and in air trapped in ice cores, which showed that such an increase in CO2 concentrations has never occurred during the 10,000 years preceding the 19th century. In parallel, the measurements of carbon isotopes (14C and 13C, which are different forms of carbon) showed an unusual decrease, providing the source of the CO2 accumulating in our atmosphere: combusted fossil fuels that only contain low amounts of 13C and no 14C. The amount of nitrous oxide has increased by 20% and the amount of methane by an even higher proportion of more than 150%. The increase in CO2 perfectly corroborates the increase in average surface air temperature which is 1 ˚C higher than in 1900. Over half of this increase has occurred since 1970, with the last decade (2010-2019) being the warmest decade since 1850. These warmer temperatures are not the consequence of a sunnier weather. Indeed, direct satellite measurements since the late 70’s show no increase in the Sun’s output. To show that the increased average temperature was due to human activity and rule out other natural causes, temperature variations over the 20th century were simulated by either considering natural factors only or by including human contribution. Only when considering the human activities, the simulations were consistent with reality 2

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Why you should worry about climate change

You may think that an increase of 1 ˚C in temperature in more than 100 years is not much, but effects of global warming have already been observed around the world. As the air temperature increases, extreme weather events become more frequent and more intense. The planet has faced more and more heat waves and heavy precipitation events. The arctic sea ice cover shrunk, the ice melted, and the heat content of the ocean is steadily increasing. With a warmer atmosphere and warmer oceans, hurricanes are expected to last longer, become more intense and larger. If we add heavy precipitations to the equation, storm surges and flooding are likely to be more destructive. As a consequence of temperature and rainfall patterns changes, many animal and plant species were perturbed: geographical ranges alterations and modifications of the timing of their life cycle were observed. CO2 alters wildlife as well, directly by affecting growth of animals and the integrity of their shells, and indirectly as it is dissolved into water and acidifies it, altering the cycling of nutrients and other elements and compounds in water 2

Human health and well-being are also, and above all, at risk. Children, low-income families, individuals with pre-existing conditions, pregnant women and the elderly are the most susceptible to climate change. The European heatwave of 2003 killed over 70,000 people and the number of people experiencing heatwaves is growing, reaching approximately 220 million in 2018. Increased temperatures can have serious effects on pregnant women, as it can affect gestational time, increasing the risk of premature birth and birth defects. The pattern of distribution of vector-, water-, and food-borne diseases is modified by climate change, which also increases mental health disorders due to weather disasters, forced migration, food insecurity, and extreme heat waves. As well as, weather conditions, another threat related to climate change is the highly polluted air we are breathing. Polluted air (mainly fine particulate matters < 2.5 µm, also called PM2.5) damages the heart, lungs, and other vital organs, leading to deadly or chronic diseases 3,4.  According to the World Health Organisation (WHO), about 4.2 million people die from exposure to ambient air pollution every year 5

A surprising consequence of CO2 concentration increase in the atmosphere is the higher plant biomass and crop yield in these conditions, resulting from a stimulation of photosynthesis. However, a warmer temperature counteracts this effect by affecting plant growth, water demand and supply balance, and climate extremes may promote plant disease and pest outbreaks, overall leading to agricultural production losses. [8] With our growing population, can we really afford to lose our food supply?

What is the situation in Vietnam?

As mentioned before, by climate change but also a contributor to the increase of greenhouse gases through agricultural waste burning. Vietnam climate is characterized by a tropical Monsoon climate influenced by the Southeast Monsoon circulation. The shape of Vietnam – long and narrow from North to South – extends over 15 degrees of latitude, which means that climatology varies a lot across the country. But did you know that Vietnam is in the top 10 countries most affected by climate change? It is in fact, according to Global Climate Risk Index 2020, the 6th country in the world most affected by climate variability and extreme weather events over 1999-2018. Temperatures increased twice the rate of global warming since 1970. As a consequence, Vietnam is the victim of increased floods, droughts and typhoons and climate-sensitive diseases (dengue fever, malaria, diarrheal diseases or influenza) are common. It is estimated that climate change directly affects 10 to 12% of the population and causes the loss of 10% of the Gross Domestic Products (GDP) of Vietnam. This makes sense if we know that agriculture, which is dominated by rice production, represents 22% of the GDP, and that agricultural production is inherently vulnerable to climate change and variability across all regions in Vietnam. Indeed, most agricultural areas across the country are experiencing a warming pattern, particularly the two largest rice production areas in the Red River and Mekong River deltas, and many other areas along the coast, which is most likely to have adverse effects on rice production 6,7

Conclusion

In Earth’s history, climate changes occurred but the speed of our current climate change is alarming. Human activities such as fossil fuel burning, deforestation and land-use changes are highly speeding the process up by producing greenhouse gases, especially CO2. Rice straw burning in Vietnam is a good example of a Human activity that is responsible for the release of greenhouse gases and other pollutants in air and water, leading to detrimental effects on ecosystems and human health. At the same time, rice straw is more valuable than we think; this biomass can be used to produce a wide variety of products that we can use in our daily life such as biofuels, bioplastics, food supplements, candles, and more… Investing in processes transforming rice straw waste into these useful products should be of interest for our society and many scientists, engineers and farmers already focus on these processes. To find out more about the worldwide accumulation of rice straw and how it can be converted into high value products, take a look at our other articles; Is rice straw accumulation affecting our planet?; Bioethanol, a carbon dioxide neutral neutral energy source; Malic acid is part of your daily life

1 S. Lewandowsky, "Climate Change Disinformation and How to Combat It.," Annual Review of Public Health, pp. 42:1, 1-21, 2021.
2 The Royal Society and the US National Academy of Sciences, "Climate Change Evidence and Causes," 2020. [Online].
3  A. Goshua, J. Gomez, B. Erny, M. Burke, S. Luby, S. Sokolow, D. LaBeaud, P. Auerbach, M. Gisondi and K. Nadeau, "Addressing Climate Change and Its Effects on Human Health: A Call to Action for Medical Schools," Academic Medicine, vol. 96, no. 3, pp. 324-328, March 2021.
4 N. Wheeler and N. Watts, "Climate Change: From Science to Practice," Curr Environ Health Rep., vol. 5, no. 1, pp. 170-178, 2018.
5 World Health Organization, "Air pollution," [Online]. Available: https://www.who.int/health-topics/air-pollution#tab=tab_1. [Accessed 24 03 2022].
6 F. N. Tubiello, J.-F. Soussana and M. Howden, "Crop and Pasture Response to Climate Change," Proceedings of the National Academy of Sciences, vol. 104, no. 50, pp. 19686-19690, 2007.
7 K. Nguyen Duc, T. Ancev and A. Randall, "Evidence of Climatic Change in Vietnam: Some Implications for Agricultural Production," Journal of Environmental Management, vol. 231, pp. 524-545, 2019.