[Biology Class Notes] on Global Warming Pdf for EXAM

Global Warming Definition: “Global warming is a consistent upsurge in the earth’s average temperature denoted by increasing global surface temperatures caused or influenced by the uninterrupted emissions of greenhouse gases, over 90% of the air getting polluted by carbon dioxide and CFCs like Methane and Nitrous oxide and other air pollutants affecting the climate sensitivity and levels of precipitation of the planet.”

Over the past 50 years, there has been a gradual rise in the Earth’s average global temperature, and over the current years, this trend has been accelerating at a faster pace. This change has severely disrupted the climatic balance of the Earth by trapping several greenhouse gas radiations in the atmosphere and causing the planet to get hotter. Dominantly, the largest source of this heat-trapping pollution lies in 1) combustion of fossil fuels, 2) Emissions from the transportation sector. 

It is also known as the ‘Greenhouse Effect,’ which is one of the major causes affecting global warming. Though the current state of global warming is considered quite controversial, authentic researches have provided pertinent data to support the same.  Widespread adoption and implementation of necessary solutions are essential to restrain these emissions and curtail the intensified effects of climate change. Now, we shall move forward to a detailed discussion on the causes and effects of global warming. 

Causes of Global Warming

“Greenhouse gases like methane, nitrous oxide and most prominently carbon dioxide along with other air pollutants is the main cause for global warming.” 

Effects- “The effects of global warming include an increase in sea levels (leading to coastal flooding), changes in precipitation (leading to more floods and droughts), increased intensity of storms, and the spread of disease vectors. The effects of global warming are already being felt around the world.”

Mitigation – “The emissions of greenhouse gases can be reduced through a number of measures such as energy conservation, use of renewable energy sources, and carbon capture and storage. It is also important to increase the resilience of communities and ecosystems to climate change impacts.”

Causes of Climate Change: 

Under this head, the causes can be divided into two factors;

1) Manmade 

2) Natural.

Global Warming: Is it a human-made cause?

Deforestation affects the release of aerosols and other chemical compounds that affect clouds and changes in wind patterns, causing a flux in precipitation levels. In basic terms, Trees and plants are responsible for being the primary source of oxygen. By taking the carbon dioxide in, they release oxygen in the air, thereby maintaining a state of ecological balance, causing lesser air pollution. Planned human activities like continued forest loss for industrial and commercial motives drive the increase in carbon dioxide concentrations. As we know, Carbon dioxide is one of the leading heat-trapping gases, mainly responsible for average warming and environmental imbalance over the past few decades. 

In this fast-paced world, people often use vehicles even for covering short distances. Gaseous emissions from cars and vehicles often drive temperature rise by trapping energy, which translates into heat. Such activities come under ‘anthropogenic forcing,’ i.e., human-influenced forces on the climate system. Continued transportation around congested areas contributes to air pollution, which eventually leads to increased global warming. According to IPCC reports, the transportation sector’s contribution has grown by more than 50% since 1992 and continues to be one of the leading causes of global warming.

In today’s state of successive climate imbalance and issues of global warming, we all know that human-made causes have very high tendencies towards rising global surface temperatures. Other factors that add up to the causes are widespread commercialization and increased use of technological appliances such as Air conditioners and refrigerators. The atmospheric ozone layer is responsible for protecting the Earth’s temperature from the sun’s harmful UV radiation. Such practices have added an extra layer of CFCs or Chlorofluorocarbons in the air, depleting the intensity of the ozone layer.

According to a report stated in 2018, some of the significant global anthropogenic greenhouse gas emissions are almost equal to 52 billion tonnes of Carbon dioxide. Out of which 72% is released from industries and power plants. With the advent of industrialization, the rising usage of electricity and heat, global warming has increased to a great extent. The release of pollutants from these sources has a significant impact on the environment and disturbs the delicate balance of nature.

Frequent practices of agriculture take up almost 50% of the world’s habitable land. Short term agricultural cultivation affects nearly 24% of the permanent land-use change. These activities also add up to the rise in temperature and GHG emissions from the land surface. The changes in land surface disturb the natural process of carbon storage and affect the reflection and absorption of sunlight heat. Soil erosion, Deforestation, and chemical fertilizers application lead to increased runoff that carries pollutants into water resources and eventually to the oceans.

Most of the heat-trapping emissions from burning coal, gas, and oil from industries and cars, along with widespread Deforestation and rising levels of black carbon pollution or ‘soot’ in the form of aerosols affecting Earth’s albedo come under this type. Also, the primary gas causing Global warming is Carbon dioxide, which is influenced by rising overpopulation.  

Natural Causes of Global Warming

1. Volcanic Eruptions: They constitute one of the significant natural causes affecting global warming because of the increased release of gases and smoke from the eruptions. 

2. Natural Forest Fires: When significant scale vegetation burns, leading to forest blaze, there is a release of stored carbon and a rise in greenhouse gas emissions. These emissions further trap solar energy leading to Global warming. 

3. Melting Permafrost and Glaciers: Towards the north and south poles of the planet, considerably large amounts of carbon are frozen in the form of permafrost. Disturbances such as solar activities, forest fires, volcanic eruptions can lead to the sudden release of GHGs and carbon sequestration into the atmosphere, giving way to ecological imbalances. 

4. Solar Activities: Changes in solar irradiance in wavelengths and other variations such as solar flares or sunspots, if larger enough, could have an unprecedented impact over global warming and atmospheric temperatures. 

Global Warming: Its Effects and Impacts

The major impacts of global warming include societal, economic, and health impacts. It can cause a lot of harm if it continues the same way as it is happening now. Here are its certain impacts: 

1. Rise in Temperature Leading to Ice Melt: Melting glaciers and snow melts will cause severe water shortages and droughts with higher frequencies giving way to heatwaves and extreme weather conditions in the mid-latitudes. Thinning ice of the northern seas will make the atmospheric conditions vulnerable to control. 

2. Ecological Risks: Global warming has contributed to the extension of drier climatic zones such as deserts in the subtropics. Mostly ecosystems and animal life will be affected by higher carbon dioxide levels and global temperatures leading to climate change, which will result in the extinction of many species and reduced ecological diversity.

3. The Threat to Marine Life: Global warming can lead to the destruction of marine and coral life underwater. Higher content of carbon dioxide in the water inflicts damage to valuable natural resources.  

4. Loss of Settlements: Global warming can also lead to Inundation from sea level rise, which can further threaten infrastructure and establishments of human settlements. This severely leads to a decrease in the human population. Droughts, temperature rise, loss of glacial rivers puts the state of agriculture on ain the rampage.

5. Health Factors: There are various indirect effects such as malnutrition inflicted by crop failures. Scanty rainfall leading to desertification can also cause several diseases due to global warming. 

Flooding in low-altitude regions: Rise in sea level and high flooding tendencies can damage human habitation and cause mass destruction. 

Conclusion

In conclusion, it is evident that global warming is a real phenomenon, and it is happening right now. There are several factors that contribute to this issue, and the impacts can be seen both socially and environmentally. If we do not take the necessary precautions and act now, the situation is only going to worsen in the future. One should be well-aware of the consequences and ensure that they are not doing anything to contribute to it.

Most importantly, if you want something done right, then do it yourself. If you know what should be done about this situation, but other people around you refuse to act or believe in climate change, then it’s time for you to take up the initiative and become the change you want to see in this world. Be kind enough to share with your friends and family to have a better understanding of this issue. 

Students can go through concepts, Definitions, and questions carefully and understand the concepts used to solve these questions. This will help the students immensely in their examinations.