The IPCC offers a survival guide for humanity

“Dear friends. Humanity is on thin ice – and that ice is melting fast.” Thus begins the latest communiqué on the report of the Intergovernmental Panel on Climate Change, a powerful video message. In the document, and to no one’s surprise, the IPCC reminds us that climate change has a large anthropogenic component. Or, put another way: it is the fault of our industry and, in a way, of us. But, setting aside this idea of ​​anthropogenic climate change, which is not exactly new, they also offer a “survival guide for humanity.” Specifically, the IPCC reports that, in principle, with enough effort, we might be able to limit the rise in temperatures to as little as 1.5 degrees.

To achieve this, he suggests accelerating steps to reach net zero emissions by 2040, and the leaders of developed countries have committed to this. Some countries have set an even more optimistic goal and propose to reach zero emissions by 2035, within just 12 years. On the other hand, it is contemplated that countries with emerging economies could delay zero emissions for a few more years, specifically until 2050. Likewise, the IPCC has taken the opportunity to recall that “This is the time for all G20 members to come together in a joint effort, pooling their resources and scientific capabilities, as well as their proven and affordable technologies through the public and private sectors, to make neutrality a reality. carbon in 2050”. Because “Both countries must be part of the solution. Requiring others to act first only ensures that humanity will be last.”

To understand the problem we have to think about the scientific foundations. Because we know that carbon dioxide is one of the main culprits, but how exactly does carbon dioxide work? The answer has several layers of complexity and, if we start with the simplest (and hackneyed) we will find an interesting contradiction. It is often said that the name “greenhouse effect” already gives us a clue and that what happens is that the sun’s radiation passes through the earth’s atmosphere, warms the planet and cannot escape again because the greenhouse gases make to bounce back to the surface, like plastics in a greenhouse. We could say that it is an adequate simplification of how these gases act, but that is not exactly how a greenhouse works. These plastic or glass structures do not retain the sun’s rays inside, but retain the overheated air that, without the greenhouse cover, would rise and be replaced by cooler air.

Specifically, in the case of the greenhouse effect, the radiation that is trapped is infrared, which is the type of “light” that transmits heat, an invisible “light”, less energetic than the colors that our eye captures, but which it is there as part of the so-called electromagnetic spectrum. In fact, if we want to understand a little better how this heating works, we will have to think about the characteristics of the molecules of the gases involved. To retain infrared radiation, they must be electrically charged, or at least unevenly distributed throughout their structure, as is the case with water. Neither oxygen nor nitrogen meet these characteristics, and they are the main gases in our atmosphere, but greenhouse gases are so efficient that, despite their relatively low concentration, they end up being enough to warm the planet.