Climate change in 10 certainties: from reasons and perpetrators to consequences and limits

Climate change is already a reality and there is less and less time left to reverse the consequences. To find out what is happening to the planet, almost 40 years ago the United Nations (UN) formed the Intergovernmental Panel on Climate Change (IPCC). It brings together scientists from all over the world who analyze, for months, scientific literature and determine what the situation of global warming is.

The previous report was made in 2014 and served to lay the foundations for the Paris Agreement, which was signed by some 200 countries a year later. Today, the guidelines that were agreed at that meeting are in check, either because they were not met or because they did not reach them. And while experts warn that time is running out and that, if it stays this course, the planet is headed for a climate catastrophe, the results of the last three IPCC reports leave no room for doubt.

1- What is the IPCC?

As the UN itself points out, the Intergovernmental Panel on Climate Change (IPCC) is a scientific body that is charged with analyzing the “most recent scientific, technical and socio-economic literature produced worldwide, relevant to understanding climate change”. In other words, it does not carry out any kind of research, nor does it monitor data or parameters related to climate. At present, 195 countries recognize the scientific authority of these reports and are also part of this intergovernmental body.

For their part, scientists participating in the IPCC do so as volunteers and ad honorem. Among the tasks they can perform can be authors, contributing authors and reviewers. Its creation took place in 1988 and aims to carry out comprehensive assessments of climate change through “scientific, technical and socio-economic knowledge”, as well as “its causes, potential impacts and response strategies”. So far, this group has produced 5 reports consisting of several volumes. In 2022, the sixth was held, although some aspects will be fully disclosed during the second half of the year.

2- Is climate change real? Whose fault is it?

The first report of the sixth installment carried out by the IPCC was emphatic: climate change is a reality and the human being is responsible. According to experts, the responsibility of humanity in global warming is “unequivocal”; since it was anthropogenic activities that “warmed the atmosphere, the ocean and the earth.” This situation caused “widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere”.

3- Why is humanity to blame for climate change?

The answer is basic, experts say. Human activities are responsible for generating greenhouse gases (carbon dioxide -CO₂-, methane -CH⸺-, and nitrous oxide -N₂O-) that raise the temperature of the planet. Although they have been present in the Earth's atmosphere for millions of years, these substances actually contributed to the planet's habitability. However, the burning of fossil fuels and some industrial, manufacturing and livestock activities broke the balance sheet.

The balance was that these released gases could be absorbed by the planet. Today, the amount of carbon dioxide released by humanity is the highest in the last two million years, while methane and nitrous oxide have reached the highest level in the last 800,000 years. But this situation has an extra addition: carbon dioxide can persist for centuries in the atmosphere and methane for decades, since the latter has a greater power of global warming.

4- How much has the temperature of the planet increased so far?

In the last decade, that is, between 2011 and 2020, measurements say that the planet's temperature rose by almost 1.1°C compared to the summarized stage between 1850 and 1900 (pre-industrial). Global warming reached 1.6°C, while in the oceanic region it is located at 0.9°C. Meanwhile, the most obvious consequences of this progression are recorded at the poles. The limit set by experts is 1.5°C to 2°C. However, scientists say that emissions need to hit a ceiling in 2025, and then fall dramatically. Otherwise, some estimates indicate that the temperature will rise to 4.4°C.

5- What is the limit that the experts set?

In the Paris Agreement, scientists pointed out that the temperature of the planet should rise to 1.5°C by the middle of the century and that by the end it could rise to 2°C. However, they warned that, despite these levels, humanity will see the consequences of extreme weather events and their consequent damage.

6- Is humanity running out of time?

This last report was emphatic: the window of time to reverse climate change is extinguishing. By 2050, humanity should reduce emissions to achieve an increase of 1.5°C, and by the end of the century there should be an emission close to zero, thus reaching 2°C. As the generation of these gases falls, some remediation plans could begin to be implemented. The ceiling for greenhouse gas emissions is 2025, although in the Paris Agreement it was set in 2030. If this course is respected, by the end of the century warming will reach 2.8°C.

7- What should be done, according to experts

“Profound and, in most cases, immediate reductions,” summarized the scientists who make up the IPCC. This action alone could achieve the targets of 1.5°C and 2°C. If the objective is to position the temperature increase below 2°C, by 2030 emissions should fall by 27% and 63% in 2050 (compared to 2019), but if it is 1.5°C, the shrinkage should be at 43% in 2030 and 84% in 2050. There is a third option: that in the coming years the planet will temporarily exceed 1.5°C and then fall sharply (23% in 2030 and 75% in 2050).

8- Are fossil fuels responsible?

One of the points reached agreement by all experts is the responsibility of fossil fuels in increasing temperatures. According to them, to reach the 1.5°C increase, coal use will have to fall by 100%, oil by 60% and gas by 70% by 2050. In the words of experts, 73% of the emissions generated by humanity lie in the use of electricity, industry and transport. It is for this reason that a migration towards renewable energy is being fought.

9- What are the consequences of global warming that are already being perceived?

“Human-induced climate change is already affecting many extreme weather and climate events in all regions,” warns the document prepared by the IPCC and assures that, at present, “unprecedented” climate phenomena are perceived, while some are already “irreversible” in the short term, and must be wait centuries or millennia to reverse them. “The scope and magnitude of climate change impacts are greater than estimated in previous assessments. Climate change is a threat to human well-being and planetary health,” the scientists said. At the same time, they warned about the loss of biodiversity and warned that between 3% and 14% of terrestrial ecosystem species will be threatened with extinction in the coming years.

10- Can climate change be remedied or reversed?

Only when greenhouse gas emissions are zero, could the planet begin to undergo a slow reversal that could last for centuries or even millennia. “By restoring degraded ecosystems and conserving, effectively and equitably, 30-50% of terrestrial, marine and freshwater habitats, society can benefit from nature's ability to absorb and store carbon, and we can accelerate progress towards sustainable development, but adequate financial and political support is essential,” said the experts who prepared the IPCC report. And they concluded: “Different interests, values and ways of seeing the world can be reconciled. By bringing together scientific and technological expertise and indigenous and local knowledge, solutions will be more effective.”

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