The Intergovernmental Panel on Climate Change (IPCC) has stated that global warming is unequivocal, that human influence on the climate system is evident, and that greenhouse gases are the highest they have ever been in history.
The IPCC also notes that many of the changes observed have been unprecedented in recent decades to millennia. The atmosphere and the ocean have warmed, the snow and ice volumes have decreased, and the sea level has risen.
The human influence is evident in light of the increasing concentrations of greenhouse gases in the atmosphere, positive radiative forcing, and the observed warming.
1. What are the causes of climate change?
The causes of climate change can be divided into those related to natural processes and those that are linked to human activity. Naturally, there have been radical changes in the planetary climate due to changes in rotation, orbit and the inclination of the Earth, or extraordinary natural events such as volcanic eruptions.
The clearest example of this modification of the climate is the glaciations, and they are produced by the change in the shape of the Earth's orbit and the inclination of the planet to its axis. Now, we are in an interglacial period (between two glaciations), and this stability of the climate has allowed the development and growth of human civilization.
The greenhouse effect is a process that occurs naturally in the Earth's atmosphere and results from the interaction between the energy that comes from the sun and some of the gases in the atmosphere called greenhouse gases. The natural greenhouse effect allows life to exist as we know it on the planet because, without it, the average temperature of the Earth would be below -18 °C.
The atmosphere is mainly composed of Nitrogen and Oxygen and only 1% by other components, including greenhouse gases. Most greenhouse gases have always existed in the atmosphere, and their cycle starts with natural processes such as:
- Water Vapor: The evaporation of water produces water vapor as it is an essential part of the hydrological cycle.
- Carbon Dioxide: Carbon dioxide is generated from the respiration of living beings, the decomposition of plants and animals, and natural fires, being part of the carbon cycle.
- Methane: Wetlands and ruminants mainly emit methane during their digestive process as it is the result of the anaerobic decomposition of organic matter.
- Nitrous Oxide: Nitrous oxide is a product of the bacterial breakdown of organic matter.
- Ozone: Ozone is the union of three oxygen atoms.
Unfortunately, there is another source of change in the global climate. This change is associated with human activities.
From the so-called Industrial Revolution to the present day, industrial processes are developed by burning fossil fuels (oil, gas, and its derivatives, such as gasoline) and by taking advantage of natural resources.
These activities are changing the composition of the Earth's atmosphere, emitting more greenhouse gases and compounds that can remain in the atmosphere for up to 50 years. Although more than half of the CO2 emitted today takes a century to be removed from the atmosphere, a part of the CO2 emitted (about 20%) remains in the atmosphere for many millennia.
In the last 800,000 years, atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to unprecedented levels. Moreover, the oceans have absorbed around 30% of the total emitted anthropogenic carbon dioxide, which has led to their acidification.
2. How does climate change affect us?
The effects of climate change are many, very diverse and, for the most part, very serious. The signs of the changes we are suffering are already evident, and we can see them in some situations such as:
The polar caps are melting. The sea surface covered by Arctic ice on the North Pole has decreased by 10% in recent decades, and the thickness of ice above water by almost 40%. Meanwhile, on the world’s other side, the ice sheet that currently covers the Antarctic continent has become largely unstable.
The glaciers are retreating. 75% of the glaciers in the Swiss Alps will likely disappear by 2050. Those responsible for the ski resort of Andermatt (Switzerland) study the possibility of covering the Gurschen glacier during the summer, a popular area for skiers, with a gigantic sheet of insulating plastic to get it to stop melting and moving.
When the ice caps and glaciers melt, the sea level increases. In the last century, this level has already increased by 10-25 cm (depending on the measure), and it is feared that the increase may reach 88 cm by 2100.
If so, the islands and coastal areas will be flooded, such as the Maldives, the Nile Delta in Egypt and Bangladesh.
Furthermore, tropical diseases, such as malaria, could spread in areas where climatic conditions are suitable for the life of the mosquito that transmits it. A temperature rise of 2°C could potentially endanger more than 210 million people.
3. What are the effects of global warming?
Like climate change, global warming is a reality that is causing alterations and imbalances in all countries of the world. The problem of global warming is the product of the irresponsible and unsustainable actions of humanity with the environment and natural resources.
Given this important environmental science issue, it is essential to know all its effects and consequences to assume mitigation measures.
Global warming mainly impacts the following aspects:
- Climate changes in different parts of the world
- Depletion of natural resources
- Precipitation reduction
- Ocean acidification
- Rising sea levels
- Melting glaciers, snow and the poles
- No ocean circulation
- Expansion of diseases such as dengue, malaria, cancer, respiratory, cardiac diseases, others
- Health effects in children and the elderly
- Deterioration of the physical and mental health of the entire world population
- Reduction of solar radiation flow
- Extinction of plant and animal species
- Increase in the range of disease vectors and pathogens
- Increase in poverty and hunger
- A decrease in the economic and social development of nations
- Reduction of the thermohaline circulation
- Reduction of the ozone layer
All these effects and impacts of global warming are caused by greenhouse gas emissions, environmental pollution, and each of the ecological disasters that human beings exert on the environment without any awareness.
4. What are the main causes of global warming?
Increase in greenhouse gases
The excessive industrial activity that has been registered in the world since the Industrial Revolution is the main cause of global warming. The vast majority of processes of this type release a huge amount of greenhouse gases that, once in the atmosphere, deteriorate the ozone layer and, at the same time, expose the Earth directly to the sun's rays.
Burning fossil fuels
A good part of greenhouse gases is generated from the burning of fossil fuels. This is observed, for example, in large urban centers with the massive burning of fuels by cars and other means of heavy transport.
The negative effect of fossil fuels is twofold if we take into account air pollution and health problems that may arise from this circumstance. For example, the World Health Organization estimates that there are currently about 300 million people in the world who have asthma, a figure that will increase proportionally to the presence of harmful substances in the environment.
Deforestation of forests
It is often thought that the deforestation of forests only generates effects in the closest environments. However, the damage that is generated is global.
Trees have the power to convert CO2 into oxygen through the process of photosynthesis, thereby contributing to reducing air pollution. But if we reduce their number, the concentration of CO2 and other gases will be higher and, therefore, the terrestrial temperatures will increase.
Forests and jungles still cover about 30% of the Earth's surface, but each year, an extension similar to that of countries like Panama is lost. Do we need to say more?
Excessive use of fertilizers
Pesticides, fertilizers, and other chemicals used in sectors such as agriculture and livestock are another direct cause of global warming. All have a high content of nitrogen oxide, which is even more harmful than carbon dioxide.
High production of waste
The high production of waste also favors global warming. How?
The more waste we produce daily, the higher the levels of methane gas in the environment. Methane is an element that is generated during the decomposition of materials in landfills.
In addition to that, consuming in bulk means a greater demand, which will increase industries' production levels and, therefore, the levels of greenhouse gases released into the atmosphere will be higher.
Food for thought
There is a lot of talk in the present times about carbon offset, carbon emissions, and climate change. Greta Thunberg’s emotional speech at the UN about climate change, criticizing world leaders, is testimony enough of how negligent we are about worrisome environmental issues in the present times.
It also sheds light on how governments throughout the world would rather handle political scenarios than the dangerous levels of global warming.
Therefore, now more than ever, there is a massive need for world leaders to heed the advice of disappointed environmentalists and informed scientists. This climate breakdown will continue escalating unless we take proper steps to mitigate the damage and reverse the destruction that has already been made to the environment.
In the words of Thunberg, “The message is that we have had enough.”