Climate Change And its Consequences

 

If my memory serves correctly, the people of Kerala experienced a heat wave in 2016. After that, in 2024, we had a hot period in April and May. Now, we have pre-monsoon showers from the second week of May. 

Most people suffer its effects as heat rashes, bunchy skin, sunburn, etc.

Sometimes, the effect of heat was intolerable in this year's El Nino time. Climate change will be worse in the coming years. In Kerala, the air is humid, and we know that hot air with humidity is more dangerous than hot, dry air. We are responsible for all these problems. We must act against these challenges to find a solution. 

Sunburns due to extreme heat

I have a question.

What is the difference between weather and climate? 

I understood it as the climate is the statistical average of weather for a longer period.

General condition

Atmospheric pressure decreases with altitude because air is absent above at higher elevations.

The pressure decreases rapidly at first, then more slowly at higher levels. In the lower atmosphere, atmospheric pressure decreases at about 3.5 millibars every 30 meters (100 feet). [1]

However, over cold air, the decrease in pressure can be much steeper because its density is higher than warmer air. 

Heat wave condition:

Heat waves usually occur in drought and summer.

• The high-pressure area strengthens at high altitudes (10,000–25,000 feet) and remains over a region for several days or weeks, resulting in heatwave formation. [6] 

It is common in the summer season in the Northern and Southern Hemispheres. The reason is that the jet stream follows the sun. 

Weather patterns change slowly in summer compared to winter. So, the movement of upper-level high pressure is also slow in summer. [1]

Satellite visualization of the 2022 Indian heat wave [1]

Let us look into the interaction of these factors and how it leads to a heat wave condition.

• When pressure is high, the air sinks toward the surface. It results in adiabatic warming and drying, prevention of convection, and cloud formation. [1]
• A reduction of clouds causes an increase in the reception of short-wave radiation to the surface due to a decrease in the reflection of short-wave radiation through clouds.

For the formation of the heat wave, the condition becomes opposite to that of the general condition.

Because of higher density at lower altitudes, the air pressure is higher. 

There is less oxygen to breathe compared to sea level at higher altitudes and more space between air molecules. 

A low-pressure area at the surface leads to some significant changes.

•  It leads to surface wind from lower latitudes that brings warm air, enhancing the warming. 
• The surface winds could be from the hot region towards the coast, resulting in heat waves in the coastal zones. 

My mother used to say that, during summer, one or two rain is not enough to cool us, and heat may increase. I think the reason may be no cooling from moisture evaporation from the soil.

 

Now, let us discuss the consequences of heat waves.

A heat wave is abnormally hot or extreme weather. [2] This year, the heat wave affected Kerala, and it was worse to withstand. [3] High humidity was another threatening factor. We know heat waves occur from climate change.[4][5]

• Greenhouse gases prevent the escape of the high wavelength radiations and heat near the earth's surface. 

Impact heat waves on the economy:

• They can reduce labor productivity
• Disrupt agricultural and industrial processes
• Damage infrastructure. [7][8] 

The tiny low-lying islands of Lakshadweep may inundated by sea level rise due to climate change.[1]

Severe heat waves have caused:

• Catastrophic crop failures.

Worsening drought [1]

• Health effects were sunburns, heat rashes, bunchy skin, and deaths due to sunstroke. 
• Increase the risk of wildfires in areas with drought. 

                                                         Wildfires intensified by heat [1]

• High electricity consumption.

Do you know how human bodies deal with heat?

It is simple physics. We have already studied this in school. It is by conduction, convection, radiation, evaporation, etc.

We know losing heat by contact is conduction.

When we turn on a fan on a hot day, we feel cool because, by convection, the heat of our body releases to the surrounding air. This mechanism works only when the temperature of the surroundings is less than that of our body. 

Electromagnetic radiation from the sun warms everything, including our body. For cooling our body, blood vessels dilate and allow excess radiation of heat from the body to the surrounding air by radiation.

Now, let me tell you how evaporation works to cool our bodies. Sweating is a common phenomenon when it is hot. The heat of our body transfers into sweat, and it evaporates, resulting in a net loss of heat. Sweating is not effective when the atmosphere is humid.

What is El Ninos and La Ninas?

It is a climatic phenomenon.

The causes and pattern of El Nino are:

• Variation of winds over the tropical Pacific Ocean and
• Variation of Sea Surface Temperature (SST) over the tropical Pacific Ocean.

No regular pattern for ENSO. It occurs as intense storms in some places and drought in others.

• The occurrence of El Nino is not predictable.
• ENSO affects the climate of the tropics and subtropics. 
• El Nino refers to the warming phase of sea surface temperature, and La Nina is the cooling phase of SST.

El Nino is associated with air temperature and SST higher values over the Indian Ocean to the Atlantic, Australia, and Indonesia. 

We are still waiting to be made aware of the exact mechanism that causes ENSO. Developing countries like India are most affected by ENSO.

 

Neutral phase: Equatorial winds gather a warm water pool toward the west. [1]

El Niño phase: Warm water pool approaches the South American coast. The absence of cold upwelling increases warming. Warm water and atmospheric convection move eastwards. In strong El Niños, the deeper thermocline off South America means upwelled water is warm and nutrient-poor. [1]

La Niña phase: Warm water is farther west than usual. [1]

If the climate change is evergreen, how can we define climate change? 

• A hundred million years ago, the world was warmer than today, and dinosaurs roamed here. There was no ice at the poles. 

Why Earth was warmer than today? 

 If you think something about volcanic eruptions, you are right. 

Volcanic eruptions are one natural factor influencing Earth's climate.

Role of Academic Institutions:

Schools can provide significant facts and knowledge about climate change to students. The matter of concern is how to fix it. 

• Schools can provide opportunities for research and the action needed to combat climate change. 
• They can demonstrate to students all the actions needed to mitigate the effect of climatic change on living things and how it works to bring fruitful results. 

We will not survive without atmospheric gases.

The climate is due to the trapping mechanism of heat in the atmosphere by gases like CO2, Methane, and N2O. 

The processes are:

• Sun rays absorb on the earth's surface
• These rays radiate back to the atmosphere with longer wavelengths than incoming radiation
• In this process, visible light becomes IR.

Earth's overall heat flow. [1]

Carbon dioxide, methane, and nitrous oxide molecules absorb these longwave radiations and transmit them back to the earth's surface.

Global warming:

• Greenhouse gases trap heat, leading to the temperature rise.
• Water temperature also rises, especially ocean temperature, resulting in the expansion of water.
• The result is sea level rise.

Melting of ice (in Greenland and Antarctica) also leads to sea level rise in sea level.

How much change we can expect? 

I mean by the end of the century.

Let me tell you. 

It depends on how much greenhouse gases get added to the atmosphere and how reflective the earth's surface is.

Most places will warm only 1 and 2 degrees Celsius in the beginning. By the end of the century, it may rise to 4 or more degrees Celsius.

Energy flows down from the sun and up from the Earth and its atmosphere [1]

Precipitation changes:

Greenhouse gas concentration in the atmosphere will raise the sea level and influence the global water cycle. Climate models suggest the influence that rainfall will be more intense over most land areas in this century. Let us look into the consequences.

• Increase in severe storms, hurricanes, and flooding.
• Coastal water table rises.
• Exerts force upward upon coastal groundwater aquifers and promote flooding on land. 

We are experiencing those disasters now.

                      Image of a house destroyed by extreme weather and flooding. [1]

As climate change worsens, India will experience more extreme weather, which will cause extra rainfall and drought.

Flooded road in Kerala

Effect of co₂:

• The world's oceans will absorb 30% of human-generated CO₂.

So, what happens after absorption?

• It leads to the production of carbonic acid, resulting in the acidification of oceans.
• Acidification promotes the breakdown of calcium carbonate and the depletion of carbonate ions.
• As a result, the skeletons of animals, such as corals, will be depleted.

Heat-related diseases

• Heat stroke and heat exhaustion are common health problems as the temperature rises.

Most affected people are:

• Those who live in tropical regions or work outdoors.
• Elderly and obese people.
• People with heart failure.
• Individuals with diabetes

Heat and humidity together are more dangerous than heat alone. 

• Hot and moist air is more dangerous than hot, dry air.

Health effects of extreme heat:

Due to extreme heat, we can have heat stroke, which the body overheats. The result is permanent damage to the brain and nerves and eventually death. 

• Heat waves can be fatal because our internal organs are sensitive to heat stress. 
• If overheated, the heart, brain, lungs, etc. would fail.

Greenhouse gas emission and crop yield:

There is an extensive connection between crop yield and greenhouse gas emissions.

Greenhouse gas creates conditions like Higher temperatures.

• High atmospheric CO2
• Floods and droughts

These factors lead to:

• Salinization of freshwater
• Shortage of water and wildfires
• Particulate matter and ozone.

Eventually, the outcome is lower crop yield, nutritional disease, mental health disorders, respiratory disease, cardiovascular disease, and maternal and newborn problems.

• Too much water and too little water make it difficult to grow crops. 

Effects of heat on the crops:

Heat and ozone are harmful to people and plants. More heat drives additional ground-level ozone production, impairing plant growth and damage. 

• Ozone toxicity may reduce crop production in the case of wheat, rice, etc.

 Recently, I have gone through a report in a newspaper, with a picture of a farmer holding a bunch of paddies damaged due to heat. The report said the farmers planned to burn the plants in the field to avoid reaping because there was no rice in the paddy. They said that the milk inside the husk drained out due to extreme heat in the growing period, and only the husk remains, with no seeds inside the husk. 

 Another threat of sea level rise

• Another threat of sea level rise is the Salinization of coastal groundwater. 

In one of the articles about Dhanushkodi, I mentioned that we can have fresh drinking water from the well at the Dhanushkodi coast (https://retnacpn.blogspot.com/2024/04/dhanushkodi-abandoned-town-in-tamil-nadu.html).

If the sea level rises in this pattern, we cannot expect that grace for long. Do you know why?

Now, what happens when the sea level rises?

• The pressure of salt water to intrude through rocks and earth into aquifers rises, which drives salt water into fresh water.

Overview of climatic changes and their effects on the ocean. Regional effects are displayed in italics.^[1]

Growing food requires fresh water. Water demand will increase in the coming decade. Withdrawal of groundwater increases worldwide, and more salt water may intrude into the freshwater aquifers.

CO2 and fish:

In tropical regions like India, we consume fish. Fish has a significant role in our menu. It contains healthier fats, protein, etc., 

We know overexploitation is there in the case of fisheries. We have a trawling ban in Kerala during the southwest monsoon season to prevent this. This year's ban is from June 9th to midnight on July 31st, 2024 (52 days). A trawling ban will help the replenishment of fish stocks. Traditional fishermen said that a ban for more than 50 days would be helpful for the fisheries sector in the long run. They suggested 90 days.

• The ocean absorbs 90% of the heat absorbed by greenhouse gases. 
• This condition makes tropical regions overheated and causes the migration of fish and other creatures from the tropics to the poles.

Fisherman landing his catch [1]

• When CO2 dissolves in seawater, the ocean becomes more acidic. 
• The acidic ocean dissolves CaCO3, which forms corals.

(H2O+CO3----Gives H2CO3. Combination of hydrogen ion H+ and bicarbonate ion HCO3)

Bleaching of coral occurs more often due to marine heatwaves [1]

Coral reefs serve as a habitat for many fishes in their life cycle. So, that is another threat to fish. 

Photosynthesis strategy

I thought trees would use CO2 to release oxygen and balance the disparity in the atmosphere. I know reforestation of all land is a big task, but we can protect the existing trees. If we cut a tree, remember to plant another one. That, we can do. I think planting trees is a mitigation tool.

Photosynthesis changes sunlight into chemical energy, splits water to liberate O₂, and fixes CO₂ into sugar. [1]

We should be careful. Climate change is not a joke. If we do not act now, it will be an invitation to catastrophe for future generations. 

                                               Schematic of photosynthesis in plants. [1]

Approach to mitigate climate change.

I think the mitigation strategy varies with regions.

• In tropical countries like India, the main contributor to greenhouse gases is transportation. 
• If we move to electric vehicles, it will be helpful and a positive approach. Vehicles running on solar energy are the best option. 

• It is appreciable if we walk or cycle. 

• Using public transportation is another option.
• Protect existing trees and try to encourage forestations.
• Avoid fossil burning as much as possible.

An example of the terms climate crisis and climate emergency being used together during a protest march [1]

So, what should we keep in mind?

The choices we make today are crucial, and they will determine the state of our future life and the future of our kids and grandkids on this planet.

References

1 Wikipedia

2 IPCC, 2022: Annex II: Glossary [Möller, V., R. van Diemen, J.B.R. Matthews, C. Méndez, S. Semenov, J.S. Fuglestvedt, A. Reisinger (eds.)]. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK, and New York, pp. 2897–2930, doi:10.1017/9781009325844.029.

3 Robinson, Peter J (2001). "On the Definition of a Heat Wave". Journal of Applied Meteorology. 40 (4): 762–775. Bibcode:2001JApMe..40..762R. doi:10.1175/1520-0450(2001)040<0762:OTDOAH>2.0.CO;2.

4^ Climate Change 2021: The Physical Science Basis. Intergovernmental Panel on Climate Change. 2021. pp. 8–10.

5^ Thompson, Andrea, "This Summer’s Record-Breaking Heat Waves Would Not Have Happened without Climate Change", Scientific American 25 July 2023

6 NWS JetStream - Heat Index". US Department of Commerce NOAA weather.gov. Retrieved 9 February 2019.

7^ Jump up to:^a b Bottollier-Depois, Amélie. "Deadly heatwaves threaten economies too". phys.org. Retrieved 15 July 2022.

8^ Jump up to:^a b García-León, David; Casanueva, Ana; Standardi, Gabriele; Burgstall, Annkatrin; Flouris, Andreas D.; Nybo, Lars (4 October 2021). "Current and projected regional economic impacts of heatwaves in Europe". Nature Communications. 12 (1): 5807. Bibcode:2021NatCo..12.5807G. doi:10.1038/s41467-021-26050-z. ISSN 2041-1723. PMC 8490455. PMID 34608159.