We explain what the greenhouse effect is and the causes of this phenomenon. Its consequences and relationship with global warming.
What is the greenhouse effect?
It is known as greenhouse effect to an atmospheric phenomenon that occurs when thermal radiation (heat) from the Earth’s surface, which is commonly emitted into space, is instead retained by greenhouse gases (GHG) present in the atmosphere due to the air pollution. This causes an increase in planetary temperature, since the heat cannot escape, as in a greenhouse. That’s where the name of the effect comes from.
The sunlight that our planet receives every day heats its surface, including the ocean waters, providing it with an enormous amount of light and heat that allows life and inject the energy necessary for its different chemical and physical cycles.
However, part of that heat energy is re-radiated out at lower frequencies (infrared radiation), allowing some margin of cooling and equilibrium.
This process is interrupted or slowed down when gases such as water vapor, carbon dioxide (CO2), methane (CH4), nitrogen oxides (NxOy) and ozone (O3) abound in the atmosphere, therefore known as gases. greenhouse effect. If there were none of these gases in the atmosphere, the average temperature of the planet would be -18 ° C and life would be impossible.
On the other hand, if these gases exceed the natural measure of their presence in the atmosphere, the accumulated heat on the planet will rise and alter the planet’s climate balance, accelerating or intensifying global warming.
Causes of the greenhouse effect
The registered margins of greenhouse gases in the atmosphere at the end of the 20th century are directly related to the beginning of human industrial activities, which have thrown so many gases of this nature into the atmosphere that the CO2 concentration rate in the atmosphere has increased by 40% since 1750 (from 280ppm to 400ppm).
The addition of carbon to the atmosphere by our species exceeds the current capacities of the planet to recycle it (through the Carbon Cycle), since it comes from almost three centuries of massive combustion of fossil hydrocarbons (coal, oil, natural gas) and other similar economic activities, such as massive cattle ranching or deforestation (which reduces the amount of plant life available to recycle environmental CO2).
It should also be considered that many of the gases released into the atmosphere by human industry are long-lived, that is to say, they are not easy or fast to decompose to recover the chemical balance of the atmosphere.
Consequences of the greenhouse effect
As stated before, the greenhouse effect it is necessary for life on the planet, since without it the heat would be released into space. Instead, the problem lies in the disproportionate increase in the gases responsible for this effect, which has a direct consequence: the gradual but sustained increase in world temperature as well. This is known as global warming and in turn has a series of consequences:
- Climate change. Rising global temperatures lead to altered tidal and hydrological cycles, disrupting the way our planet distributes heat and cools itself. Thus, climates are turned into extreme versions of themselves: longer and harsher winters, more oppressive and drier summers. When it rains, it floods; when not, there is drought.
- Melting of the poles. The ice caps at the poles serve as a natural refrigerator for the planet, and also conserve a significant percentage of fresh water in a solid state. The increase in temperature gradually reduces them, thus generating an acceleration in the heating, since there is less ice to counteract it and so on. This, moreover, implies that the sea level rises: fresh water will raise the coastline of the continents and many cities can be under water.
- Generation of new deserts. Such violent climate change does not give life a chance to adapt to new temperature conditions, which leads to the generation of new deserts or the lengthening of existing ones.
- Climatic catastrophes. Longer and more intense hurricane seasons, tropical storms with more rain than usual and other similar phenomena are a consequence of the global climate imbalance.
Greenhouse effect and global warming
The nexus between the prolonged emission of greenhouse gases and global warming is proven by scientists, despite the fact that there was much disbelief and much debate about it.
Some sectors, especially those that would have to make the greatest efforts to reduce CO2 emissions into the atmosphere (precisely the industrial sectors of the most developed countries), they insisted it was a natural warming cycle, product of the end of an ice age.
And while this is still true in terms of geological time, neither does the increase in the level of greenhouse gases in the atmosphere rebound and accelerate enormously since the Industrial Revolution of the 18th century.