Greenhouse effect
The consequences of the greenhouse effect: from desertification to floods
Human action is causing an increase in global temperature. For that reason, the greenhouse effect, far from being our great ally as was the case in the past, is now a risk to our survival. The flooding of coastal cities, the desertification of fertile areas, the melting of glacial masses and the proliferation of devastating hurricanes are just some of the main consequences.
What is the greenhouse effect
The greenhouse effect is a natural phenomenon and is beneficial for us. Certain gases in the atmosphere retain part of the thermal radiation emitted by the Earth's surface after being heated by the sun, this maintains the planet's temperature at a level suitable for the development of life.
Human action — through activities such as industry, intensive agriculture and livestock farming, or transport —, however, has increased the presence of these gases in the atmosphere — mainly, carbon dioxide and methane as a result of the burning of fossil fuels such as coal, oil or gas —, causing them to retain more heat and to increase the temperature on the planet. This is what we know as global warming.
How the greenhouse effect is produced
Numerous gases that are part of the atmosphere absorb the Earth’s infra-red radiation, producing an increase in the temperature of the surface of our planet and the atmospheric layer that surrounds it
Layer of greenhouse gases
- Carbon dioxide
- Water vapour
- Nitrous oxide
- Methane
- Sulphur hexafluoride
- Chloro-fluorocarbons
- Hydro-chlorouorocarbons
- Hydro-fluorocarbons
- Solar radiation
- Radiation escaping into space
- Irradiated heat into surface
Evolution of CO₂ (Gt)
CO₂ is the gas that contributes the most to the greenhouse effect. We present the history of emissions in the world during the last decade.
The greenhouse effect occurs when certain gases in the atmosphere, such as carbon dioxide (CO₂), methane, water vapour and nitrous oxide, absorb part of the infrared radiation emitted by the Earth's surface and retain heat, increasing the planet's temperature. Global CO₂ emissions also rose from 35.5 gigatonnes (Gt) in 2014 to 38.6 Gt in 2024, highlighting the role this gas plays in global warming.
SEE INFOGRAPHIC: Do you know how the greenhouse effect is produced? [PDF]
Difference between the greenhouse effect, global warming and climate change
Although closely related, the greenhouse effect, global warming and climate change do not mean the same thing.
- Greenhouse effect. This is a natural process in which certain gases in the atmosphere retain some of the heat emitted by the Earth's surface. Thanks to this process, the Earth maintains a temperature suitable for life to thrive. The problem arises when human activities increase the concentration of these gases, strengthening the greenhouse effect.
- Global warming. This is the gradual increase in the Earth's average temperature, caused mainly by the build-up of greenhouse gases released through activities such as burning fossil fuels, deforestation, industry, agriculture and livestock farming.
- Climate change. This refers to the long-term changes largely driven by global warming, including shifts in rainfall patterns, droughts, heatwaves, melting ice, rising sea levels, changes in the oceans and an increase in the intensity or frequency of certain extreme weather events. These changes also affect ecosystems, human health, economies and societies.
In short, the greenhouse effect is the mechanism, global warming is the rise in temperature and climate change encompasses the wide-ranging consequences of that warming.
Main greenhouse gases
Not all greenhouse gases come from the same sources or remain in the atmosphere for the same length of time. Their ability to retain heat also varies. The main greenhouse gases linked to human activity include:
- Carbon dioxide (CO₂). Produced mainly by the burning of coal, oil and natural gas, as well as by deforestation and other land-use changes. It is the greenhouse gas that contributes most to human-caused global warming because of the large quantities emitted and its long-lasting presence in the climate system.
- Methane (CH₄). Emitted by activities such as livestock farming, rice cultivation, the decomposition of waste in landfill sites and the extraction and distribution of fossil fuels. Although it remains in the atmosphere for a shorter period than carbon dioxide, it traps much more heat while it is present.
- Nitrous oxide (N₂O). Mainly associated with the use of nitrogen-based fertilisers, manure management and certain agricultural and industrial processes. It has a high global warming potential and can remain in the atmosphere for more than a century.
- Fluorinated gases. These are synthetic gases used in industrial processes, refrigeration and air conditioning systems, and the manufacture of certain products. Although emitted in much smaller quantities, some have an extremely high global warming potential and can remain in the atmosphere for hundreds or even thousands of years.
These differences show that tackling climate change requires action across multiple sectors, including energy production, transport, industry, agriculture, livestock farming and waste management.
Consequences of the greenhouse effect
The increase in the average temperature on Earth is changing living conditions on the planet. Let's find out about the main consequences of this phenomenon:
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Thawing of glacial masses
Glaciers retreat also has its own consequences: reduced albedo — the percentage of solar radiation that the earth's surface reflects or returns to the atmosphere —, a global rise in sea level and the release of large methane columns are only some of them, however, they are all dramatic for the planet.
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Flooding of islands and coastal cities
Rising sea levels threaten the communities, infrastructure and ecosystems located along the world's coastlines. According to NASA satellite measurements, global mean sea level rose by approximately 10 centimetres between 1993 and 2024. The annual rate of sea level rise has also more than doubled over that period. This trend is driven mainly by the melting of glaciers and ice sheets, together with the expansion of seawater as it warms.
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Hurricanes will be more devastating
The intensification of the greenhouse effect does not cause these extreme climatic events, but it does increase there intensity. Hurricanes formation are connected with sea temperature — they only form over waters that have a temperature of at least 26.51 ºC —. In 2022, the Mediterranean in Spain reached 31 degrees Celsius, with 95 % of the days being warmer than usual.
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Migration of species
Many animal species will be forced to migrate in order to survive the changes to climate patterns caused by rising global temperatures. Studies in Canada have shown that many migratory bird species are arriving earlier in spring and delaying their autumn migrations as winters become shorter. Humans are also likely to be displaced: according to the World Bank, without sufficient climate and development action, as many as 216 million people could become internal climate migrants by 2050 across the six regions analysed in its Groundswell report.
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Desertification of fertile areas
Global warming is having a profound impact on the processes of soil degradation and is contributing to the desertification of areas on the planet, a phenomenon that destroys all the biological potential of affected regions, turning them into barren and unproductive land. As recognised by the UN on the occasion of the World Day to Combat Desertification in 2018, 30% of land has been degraded and lost its real value.
In recent years, almost 12 million hectares
have been lost annually, 40% of degraded lands are also in vulnerable areas, which is leading to serious problems for the food security of almost 3 billion people, according to the UN. -
Impact on agriculture and livestock
Global warming has already altered the length of the growing season in large parts of the world. Similarly, variations in temperature and the seasons influence the proliferation of insects, invasive weeds and diseases that could affect crops. The same is true of livestock farming: climate variations directly affect the main species in a number of ways, including reproduction, metabolism and health.
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Economic and social impacts
Rising temperatures also have significant economic consequences. Extreme weather events damage infrastructure, homes and crops, requiring governments and communities to spend billions of euros on reconstruction every year. In addition, sectors such as tourism, fisheries and agriculture depend directly on climate conditions, making them particularly vulnerable to global warming. This situation also deepens social inequalities, as communities with fewer resources are often the most exposed to climate risks and the least able to adapt to their effects.
Consequences of the greenhouse effect for mental health and society
The intensification of the greenhouse effect not only affects ecosystems and the climate, but also has direct consequences for health, food security, access to water and the living conditions of millions of people.
- Physical health. Rising temperatures and the increasing frequency of heatwaves raise the risk of dehydration, heatstroke, cardiovascular disease and respiratory illnesses. These impacts are particularly severe for older people, children, people with chronic health conditions and those who work outdoors.
Changing climate conditions also favour the spread of disease-carrying insects. Mosquitoes capable of transmitting infections such as dengue fever, malaria and the Zika virus are expanding into regions where temperatures were previously too low for them to survive. - Mental health. The climate crisis also affects psychological wellbeing. Eco-anxiety – the persistent worry caused by environmental degradation and uncertainty about the future – is becoming increasingly common, particularly among younger people.
In addition, people affected by floods, wildfires, hurricanes and other extreme weather events may experience post-traumatic stress disorder (PTSD), anxiety or depression. Losing a home, a job or a livelihood can create a profound sense of insecurity and have long-lasting emotional consequences. - Food security and access to water. Droughts, extreme temperatures and changing seasonal patterns affect agricultural and livestock production. Lower crop yields can lead to food shortages, rising prices and reduced access to adequate nutrition.
At the same time, declining rainfall and the depletion of some water reserves threaten access to safe drinking water. This can increase competition over water resources and has the greatest impact on regions with limited infrastructure and fewer economic resources. - Climate migration and inequality. The loss of productive farmland, flooding, water scarcity and the destruction of homes are forcing many people to leave the places where they live. These climate-driven movements may take place within a country or across international borders.
The consequences of climate change are not felt equally. Communities with fewer resources often live in more vulnerable areas and have fewer means to protect themselves, rebuild their homes or relocate. For this reason, the climate crisis is not only an environmental challenge, but also an issue of inequality and social justice.
How to address the consequences of climate change
Climate action must advance on two complementary fronts. On the one hand, greenhouse gas emissions must be reduced to limit global warming. On the other, societies need to prepare for the impacts that are already occurring or can no longer be fully avoided. These two approaches are known as mitigation and adaptation.
Mitigation
Mitigation includes the measures aimed at reducing greenhouse gas emissions and limiting their concentration in the atmosphere. Achieving this requires transforming the way we produce and consume energy and resources through actions such as:
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Decarbonising the energy system
Reducing dependence on coal, oil and natural gas – the main sources of human-caused carbon dioxide emissions.
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Expanding renewable energy
Solar, wind and other low-emission energy sources make it possible to generate electricity without relying on the continued use of fossil fuels.
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Improving energy efficiency
Buildings, industries, household appliances and transport networks must use less energy while delivering the same services.
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Electrifying end uses
Replacing fossil fuel-based engines, heating systems and industrial processes with electric alternatives can significantly reduce emissions, particularly when the electricity comes from renewable sources.
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Promoting sustainable mobility
Public transport, walking, cycling, rail travel and low-emission vehicles can reduce both energy consumption and air pollution.
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Supporting the circular economy
Reducing unnecessary consumption, repairing, reusing and recycling products helps limit resource extraction, waste generation and the emissions associated with manufacturing.
These measures require technological, economic and social change, supported by public policies that enable a fair and accessible transition for everyone.
Adaptation
Adaptation brings together the measures designed to reduce the damage caused by climate change and strengthen the ability of communities and ecosystems to recover from its impacts. Key actions include:
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Protecting coastlines
Careful urban planning, coastal defences, the restoration of dunes and wetlands, and, where necessary, the planned relocation of infrastructure can reduce the risks associated with rising sea levels and coastal flooding.
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Restoring ecosystems
Restoring forests, rivers, wetlands and other natural habitats helps conserve biodiversity, store carbon and protect communities from floods, droughts and extreme temperatures.
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Managing water resources efficiently
Improving water supply networks, reducing losses, reusing water, protecting aquifers and adapting agriculture to increasingly variable water availability are all essential.
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Building heat-resilient cities
Expanding green spaces, creating shaded areas, improving building insulation and implementing heat emergency plans can reduce the impacts of heatwaves.
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Strengthening healthcare systems
Health services need early warning systems, protocols for extreme heat events, surveillance of emerging diseases and sufficient resources to protect the most vulnerable.
Adaptation cannot eliminate all climate risks and has its limits, particularly as global warming and environmental degradation intensify. For this reason, adaptation cannot replace emissions reductions: the less we mitigate climate change, the more difficult and costly adaptation will become.
Find out more about the consequences of the greenhouse effect
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