What is climate change?

Climate change refers to a set of significant and long-lasting changes in the Earth's weather patterns. These can manifest themselves as variations in average temperatures, precipitation, winds and other weather phenomena. Although climate has changed naturally throughout the planet's history due to factors such as volcanic eruptions, changes in the earth's orbit and solar fluctuations, the term is commonly used today to describe changes attributed to human action, such as the burning of fossil fuels, deforestation and intensive agriculture.

 These activities increase concentrations of greenhouse gases (GHGs) in the atmosphere, such as carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), leading to global warming and triggering a cascade of effects on climate systems, natural ecosystems and human communities.

Why are they called greenhouse gases (GHGs)?

The term greenhouse gases (GHGs) is due to their ability to trap heat in the Earth's atmosphere, functioning in a similar way to the glass in a greenhouse or the windscreen of a car that is closed. This phenomenon is known as the greenhouse effect and is essential for maintaining a habitable temperature on the planet.

How does it work?

1. Solar energy: sunlight passes through the atmosphere and reaches the earth's surface, where it is absorbed and transformed into heat.
2. Re-emission of heat: some of this heat (infrared radiation) is returned to space.
3. Heat trapping: GHGs (such as CO₂, CH₄ and gaseous H₂O) capture and re-emit infrared radiation, trapping heat in the atmosphere and preventing it from escaping completely into space.

This is a natural and necessary process to keep the Earth from being too cold. However, human activities have increased the concentration of these gases, intensifying the greenhouse effect and contributing to global warming.

What is global warming and what are its dangers?

Global warming refers to the sustained increase in the Earth's average temperatures mainly due to the increase in greenhouse gas (GHG) concentrations caused by human activities. This phenomenon has profound implications and serious risks for ecosystems, human societies and the balance of the planet.

Implications of global warming

1. Rising temperatures: higher temperatures alter regional climates, melt glaciers and raise ocean temperatures.
2. Melting ice and sea level rise: melting glaciers and polar ice sheets, along with thermal expansion of water, contribute to sea level rise, threatening coastal areas.
3. Alteration of ecosystems: climate change affects natural habitats, endangering many species that cannot adapt quickly.
4. Extreme weather events: more intense storms, hurricanes, prolonged droughts, heat waves and forest fires are becoming more frequent and severe.
5. Ocean acidification: the oceans absorb a large amount of CO₂, which increases their acidity and threatens marine life, especially devastating corals and molluscs.

Risks associated with global warming

1. Risks to human health:

• Increased incidence of respiratory and cardiovascular diseases, due to heat waves.
• Expansion of vector-borne diseases, such as dengue fever and malaria, due to changes in climatic zones.
• Water and food shortages, causing malnutrition and dehydration.

2. Economic risks:

• Agricultural losses due to droughts, floods and changes in rainfall patterns.
• Impact on infrastructure due to more frequent and severe natural disasters.
• Significant costs to mitigate damage and adapt to climate change.

3. Risks to human communities:

• Displacement of people due to loss of habitable territories (climate refugees).
• Conflicts over resources such as water and agricultural land.
• Disproportionate impact on vulnerable communities, especially in developing countries.

4. Risks to biodiversity:

• Extinction of species that cannot adapt to change in their habitats.
• Alterations in food chains and the balance of ecosystems.

Global warming is not only an environmental challenge, but also an economic, social and ethical one. Although the consequences are already visible, there is still time to mitigate its effects by reducing greenhouse gas emissions, adopting renewable energies, conserving forests and reforestation, and implementing sustainable policies.