Global warming – Myth or reality? [English]

Within the scientific community, there is a strong consensus regarding the existence of a global warming process, whose consequences would be devastating if no action is taken to stop it. However, there are many people – from normal citizens to the president of the United States –  denying climate change. Thus, in this first Weekly Post, we will try to answer a few questions in order to counterattack these mindset, such as: What is climate change? How do we know that it exists? And finally, why some people deny the problem?

So, what is climate change?

First, let’s start by explaining the main differences between “climate” and “weather”.

  • Weather is the day-to-day state of the atmosphere. As we all know, weather can change very quickly and its forecast is not always accurate – even for the very next days.
  • Climate, on the other hand, is the weather of a place, region, or even the whole globe, averaged over a long period of time. As opposed to the weather, climate tends to be usually very stable over time.

Thus, climate change may be defined as a long-term change in weather patterns. The climate change that we are experiencing nowadays is mainly characterized by:

  • An increase on the global average temperature.
  • An increase on the number and severity of extreme weather events (e.g.: heat waves, hurricanes, etc.).

How do we know climate changes do exist?

There are a certain number of gases, which we know as greenhouse gases, that absorb the heat emitted by the Earth surface and re-emit this heat back to Earth. This effect, known as greenhouse effect, forces the Earth surface to become warmer than it would be otherwise. This interaction between the thermal radiation and the molecules of greenhouse gases is well known by the scientific community.

The greenhouse effect occurs naturally on the Earth and in other planets, and it is essential for the planet’s habitability. Without the greenhouse effect, the average surface temperature of the Earth would be -18ºC, instead of +15ºC.

However, due to human activities, the concentration of greenhouse gases is increasing to very dangerous levels, not seen in the last hundreds of thousands of years, and this is our reason for concern. In fact, we can see on the figure below how the concentrations of carbon dioxide (the greenhouse gas that contributes the most to global warming) and the global average temperatures have changed during the last century. The correlation is clear, the higher the greenhouse gases concentration, the higher the average temperature of the Earth.

Carbon dioxide concentrations and global average temperatures correlate.

Then, why so many people denies it?

Some people, especially those in positions of power, deny climate change just for economic interests – they cannot say that they are very concerned about climate change and keep on burning fossil fuels, which is the main cause of climate change. This powerful people may make other people to believe that climate change is false.

Some of the reasons that they provide (and our answers to them) are:

  • “We can’t predict weather for the next day accurately. How could we be able to predict the weather for the next centuries?”. Yes, of course, we cannot forecast the weather for the next centuries. However, with the knowledge of past trends, we can predict the climate for the future with certain confidence. So here, we can see how they mix the concepts of “weather” and “climate” to tell a false story.
  • “How can someone say that there is global warming with this extreme cold wave that we are suffering?”. Again, “weather” and “climate” are mixed. Having a strong cold wave in winter is not a proof that climate change does not exist. And following the same reasoning, having a surprisingly warm february is not a proof that climate change does exist. The only information that should be used as a proof for climate change is long-term changes in weather patterns.
  • “There is no consensus on climate change”. 97% of climate experts agree humans are causing global warming. It is true that the uncertainties about climate change are large, and that there are many processes and cycles that we do not fully understand. It could occur that, in the end, the effects of climate change are less serious than expected – but it could happen that they are even harsher than expected.

In any case, the “most likely” consequences of climate change are severe enough – so we should not take unnecessary risks and take actions to drastically cut down our emissions instead. Global warming is here, but the good news is that we have the tools to stop it before it is too late.

So this is our article for today! We are looking forward to answering your questions and to reading your reactions in the comments section. Next week, our article will talk about packaging and its impacts on the environment. See you next Thursday 🙂

Author: David Córcoles Fernández – Speciality: Energy access & energy transition

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