Greenhouse gases (GHGs) are compounds that occur naturally and anthropogenically on Earth. Without them we could not live, but their increase has endangered the planet. Halting their proliferation is key to reducing global warming and thus slowing climate change and its impact on the ecosystem. This implies transforming the current production model, but also the way we consume and live. We need to move towards a greener and more circular economy.
- What is the greenhouse effect?
The greenhouse effect is a natural phenomenon that helps to maintain the Earth’s temperature at conditions suitable for life. It prevents the thermal radiation that reaches our planet from the Sun from bouncing back outwards, retaining some of its heat and distributing it over the Earth’s surface. Without it, instead of the current average temperature of 13°C, we would experience temperatures as low as minus 18°C. The Earth would be a huge mass of ice where animals, plants and humans would find it very difficult to live in the conditions we know today.
- What are greenhouse gases?
Substances that absorb infrared radiation from the Sun and keep heat in the atmosphere are called greenhouse gases (GHGs). They are largely responsible for this phenomenon.
The problem with these compounds is that, in addition to being naturally present on Earth, they can also be man-made. In fact, human activity is the main cause of greenhouse gas emissions and one of the greatest enemies of our ecosystem. According to the World Meteorological Organisation (WMO), the last six years have been the warmest since pre-industrial times and, if nothing is done, global temperatures are likely to rise above 1.5ºC from 2024 onwards.
- Main greenhouse gases
Not all GHGs come from the same sources and not all have the same impact on the planet. These are the main greenhouse gases:
Carbon dioxide (CO2)
This is one of the best known greenhouse gases. It is so because of its role in the production of the greenhouse effect, but also because of its impact on the environment. Its proliferation is closely linked to human activity, its production model and energy consumption. The use of fossil fuels in sectors such as industry and transport are behind the proliferation of this type of substance.
Although its warming potential is higher than that of carbon dioxide, its presence on the planet is lower than that of carbon dioxide. To give you an idea of its effects, here is a fact: in a century, one tonne of methane could warm the planet 23 times more than the same amount of CO2. Methane is a compound that, in addition to being found naturally on Earth, can be created by human activity. The use of fossil fuels for the manufacture and distribution of products, increased farming and landfill are some of the causes of the growth in methane gas emissions. According to the environmental organisation Oceana, it is responsible for 15% of global warming.
Nitrous oxide (N2O)
Nitrous oxide, like methane, is found in lower concentrations than carbon dioxide. But just because it is smaller does not mean that it is less important. In fact, N2O is one of the most important greenhouse gases. So much so that, if no action is taken to reverse the situation, in 100 years its effect will be 300 times greater than that of CO2. Extensive agriculture, the use of nitrogen-based fertilisers and the treatment of animal waste are some of the activities that increase its presence on the planet.
Another of the main greenhouse gases and also one of the most persistent: it remains in the atmosphere for 50 to 100 years. Its increase is to be found, among others, in the refrigeration and aerosol propellant industries.
Water vapour (H2O)
Although water vapour is not a GHG as such, it is one of the main greenhouse gases. Its increase depends on the increase of other greenhouse gases. In other words, the more GHG emissions there are on the planet, the higher the global temperature and the more water evaporation there will be. The vapour that is generated will cause temperatures to rise even more and the process will repeat itself.
- Consequences of the greenhouse effect
As we have explained, the greenhouse effect, as well as the gases that make it possible, are necessary for life as we know it. The problem is that human action has increased the presence of GHGs on the planet and these substances, in turn, have increased temperatures, accelerating global warming and climate change.
The consequences of the greenhouse effect are already visible and, if nothing is done, they will continue to grow:
One of the major consequences of the greenhouse effect is the rise in temperatures, which are becoming increasingly extreme. According to WMO researchers, the highest temperatures since 1880 have not been recorded since the last six years.
Melting of glaciers
Global warming is causing glaciers to melt. This melting is not only increasing temperatures but also raising global sea levels. According to NASA, sea levels have risen by 20 centimetres in the last century.
As sea levels rise, so does the risk of flooding on islands and in coastal areas. By the year 2100, it is expected to rise by 15 to 90 centimetres, putting 92 million people at risk.
Desertification is one of the major consequences of the greenhouse effect. It consists of soil degradation and, in addition to rising temperatures, other factors such as lack of rainfall, forest fires, irresponsible exploitation of water resources and the growth of urban areas are also involved.
Famine and food shortages
Desertification results in a reduction of fertile soils and thus of agricultural land and food shortages.
Another consequence of the greenhouse effect is increased migration of both people and animals. As temperatures rise, so does the likelihood of drought, natural disasters, desertification, famine and the need to flee to safer and more fertile areas.
- How can the greenhouse effect be avoided?
Avoiding the consequences of the greenhouse effect is not only possible, it is necessary. Entities and citizens can do it by implementing these measures:
Use of sustainable mobility
Transport is one of the main responsible for the increase of GHGs in the atmosphere and also of polluting substances that damage our health and that of the planet. This is why reducing its use is so important to avoid the greenhouse effect. Cycling, walking and public transport are sustainable and environmentally friendly mobility options. In the case of road transport, it is best to opt for electric vehicles.
Waste management and recycling
Waste is one of the biggest problems facing the planet. There is more and more of it, because we are consuming more and more unrestrainedly. Moving towards a circular economy is key to avoiding the greenhouse effect. This means reducing the consumption of disposable products, reusing those that are in good condition and recycling those that have completed their life cycle to turn them into new objects.
One of the activities that generates the highest GHG emissions on the planet is the burning of fossil fuels. This is why it is so necessary to move towards an energy system that gives priority to renewable technologies. They are clean, inexhaustible and, in addition to being environmentally friendly, they provide a boost to the economy.
5.1. Measuring your carbon footprint
Travelling, turning on the air conditioning, surfing the Internet, eating, getting dressed… Every day we carry out activities that emit greenhouse gases and have a negative impact on the planet. This impact is called our carbon footprint. It is an indicator that reflects the amount of GHG generated directly or indirectly by the activities we carry out.
To measure the carbon footprint, the following formula is used:
Carbon Footprint = Consumption Data x Emission Factor
The consumption figure refers to the activity carried out, while the emission factor takes into account the amount and type of greenhouse gases emitted.