Climate change is, without a doubt, one of the greatest challenges facing society today. Although we have always used the polar bear as a symbol of these changes, climate change is far from just affecting these animals. The impacts of climate change are significant and affect everything from our health to food production. Next, you will better understand what climate change is and how it affects our life and that of other living beings on the planet.

But what exactly is climate change and what causes it?

Climate changes are changes brought about in long-term weather patterns based on weather changes, that is, the weather conditions observed over a period of time. They can be caused by natural processes and also by human action. Follow the chart below:

Solar incidence: The solar radiation that reaches the surface can vary, being higher or reduced in some periods.

Burning of fossil fuels, which emits greenhouse gases into the atmosphere.

Earth's orbit: The planet undergoes variation in its orbit according to the movements it performs, which makes it receive more or less solar radiation.

Increase in deforestation, that is, the removal of vegetation cover.

El niño and La Niña: These phenomena cause changes in the average temperature of the waters of the Pacific, modifying the climatic conditions of the areas in which they act.

Emission of polluting gases into the atmosphere by industries and automobiles.

Volcanic activity: Volcanoes can have periods of increased activity. In situations of high occurrences of volcanic eruptions, the Earth's climate cooling system occurs.

Pollution of soil and water resources, which alters the environmental balance.

When did the climate start to change?

Climate change did not happen overnight. Our evolutionary history is intrinsically linked to changes in climate, which have been observed since the formation of planet Earth. Over the 4.6 billion years of the planet, the climate has changed. There have been, in the last 400,000 years, four different cycles, glacial and interglacial.

In the last 150 years, however, the temperature of the planet has increased considerably. Studies indicate that the Earth warms by about 0.2°C per decade. Studies by NASA and NOAA (National Oceanic and Atmospheric Administration) show that the temperature recorded on Earth in 2018 was the fourth highest in the last 140 years. In 2017, the temperature increased by about 0.83ºC based on the average temperature recorded between the years 1951 and 1980. The highest average annual temperature was recorded in the year 2016.

The increase in temperatures started especially in the Post-Industrial Revolution period.

But why did the temperature rise? According to the World Meteorological Organization, the planet is warmer than in the period before the industrialization process. The world scenario after the Industrial Revolution changed not only economically, but also the production mode, causing changes in the environmental scenario.

Excessive consumption and high production, in addition to increasing the exploitation of natural resources, also caused an increase in atmospheric pollution, due to the emission of polluting gases by industries and automobiles. Production also accelerated deforestation, which also caused changes in the climate.

IPCC

The Intergovernmental Panel on Climate Change (IPCC) is a body created with the main objective of making assessments about climate change, being responsible for creating documents that show what is actually happening with the planet, our role in this process and the future prospects of that impact. Its creation, in 1988, took place at a time when the role of man in relation to the increase in the Earth's temperature was becoming increasingly clear.

The first report was published in 1990 and highlighted the importance of international cooperation to prevent the damage caused by climate change. This report was instrumental in the creation of the United Nations Framework Convention on Climate Change (UNFCCC), the main international treaty aimed at reducing global warming.

The IPCC periodically releases important data on climate change in the world, which is essential for the formulation of international climate policies. In the report published in 2007 (fourth report), for example, the IPCC highlighted very worrying data. According to this report, the increase in global temperature by 2100 would be between 1.8ºC and 4ºC, the latter scenario being catastrophic.

The poster above makes an appeal for environmental preservation with the words “no nature, no future”.

The IPCC's fifth report provided the scientific basis for the Paris Agreement, an international commitment signed by 195 countries that has as one of its objectives to keep the global average temperature increase to less than 2ºC above pre-industrial levels. This agreement also foresees efforts to limit the increase to 1.5ºC above pre-industrial levels.

In 2018, the IPCC released the Intergovernmental Panel on Climate Change (IPCC) Special Report on global warming of 1.5 °C, which presents important information to ensure correct decision-making by governments in order to avoid the increase temperature exaggerated.

According to that report, it is essential that the global temperature does not rise 2°C above the temperature levels before the Industrial Revolution, as this could have disastrous consequences such as loss of biodiversity, loss of habitat, shrinking polar ice caps, etc. To ensure that heating does not exceed 1.5°C, quick changes are essential.

What is the relationship between the greenhouse effect, global warming and climate change?

The gases present in the Earth's atmosphere, such as carbon dioxide, prevent all solar radiation from being returned to space, trapping heat.

Since the Industrial Revolution, tons of greenhouse gases, especially carbon dioxide, have been released into the atmosphere. It is known that the Earth's atmosphere is formed by gases such as oxygen, nitrogen, carbon dioxide and also water vapor. These gases, mainly carbon dioxide, have the ability to absorb solar radiation emitted to the earth's surface.

This absorption prevents heat from being completely returned to space, retaining it. The portion of heat retained causes energy balance, thus avoiding a large thermal amplitude, that is, a large difference between the maximum and minimum temperatures. By keeping the Earth's average temperature around 14°C, the Earth then presents favorable conditions for the existence of life. This natural process is called the greenhouse effect. Therefore, if it did not exist, there would be no development of living beings.

When talking about the greenhouse effect, many people associate it with something bad, but it is essential for the maintenance of life on Earth. The problem is that this natural process that maintains the Earth's average temperature has been aggravated mainly by human action. Industrial activities and the increase in vehicles that emit polluting gases into the atmosphere are responsible for the highest concentration of gases.

As these gases act in the absorption of heat, this has been prevented from being returned to space, being then trapped in the Earth's atmosphere. This imprisonment has caused a considerable increase in Earth's temperatures, which, associated with increased levels of deforestation and pollution, causes what we call global warming.

Climate change and environmental impacts

Climate change generates a series of serious environmental consequences, many of which can even be observed today. One of the consequences of the increase in the planet's temperature is the rise in sea level, which occurs due to the melting of glaciers. This can result in the flooding and submersion of coastal areas, causing a lot of harm to people living in these areas.

Melting glaciers will cause sea levels to rise.

High temperatures can also cause severe droughts, which will actively affect agriculture, causing several problems in relation to food production. IPCC data from 2019 indicate that global warming can cause a reduction in corn crops in Brazil by 5.5% for each degree of warming. With the decrease in food production and the consequent increase in prices, many people will suffer from the issue of food security, that is, with access to quality food, in sufficient and permanent quantity.

In addition to affecting agriculture, the drought is related to the increase in fires and water shortages. This last problem could lead part of the population to suffer from low availability of drinking water and could generate competition for this resource.

Rising temperatures can lead to episodes of extreme drought.

While some areas will experience extreme drought, in some regions there may be an exaggerated increase in rainfall. This could cause problems such as flooding and landslides in areas with large numbers of people.

Several animals and plants, both terrestrial and aquatic species, will be directly affected by climate change, which will cause changes in their habitat. This will lead to the extinction of a large number of species, thus reducing biodiversity. A study published in the journal Ecology and Evolution concluded that global warming could drive 10% of the species of frogs, frogs and frogs endemic to the Atlantic Forest to extinction in about 50 years.

Another important point concerns the health of the population. In addition to air pollution getting worse in different parts of the world, causing cardiovascular and respiratory diseases, some diseases, such as dengue and malaria, which are transmitted by mosquitoes, may spread to more places in the world.

What must be done to contain climate change?

Concern about issues related to climate change and its consequences are discussed around the world through several environmental conferences. These conferences bring together representatives from several nations to evaluate research, studies and data obtained about the climate and its changes and also seek to present possible actions that can alleviate the problems caused by climate change.

These conferences resulted in some agreements between the countries in order to reduce the emission levels of greenhouse gases, as well as to promote actions with the objective of containing global warming. As mentioned earlier, one of them was the Paris Agreement. Another example is the Kyoto Protocol, signed in 1997 and which entered into force in 2005 with the objective of proposing targets to developing countries in order to reduce carbon dioxide emissions and also rely on voluntary action by developing countries.

Controversies

Despite the numerous evidences about climate change, there is no consensus on these changes. Some scholars and also governments of some countries believe that the changes caused in the climate are the result of natural processes and that the Earth is, in fact, on the way to a new glaciation. For global warming skeptics, studies on climate change are alarmist, generating unnecessary concern.