As the COP26 climate summit kicks off in the Scottish city of Glasgow amid projections of an apocalyptic future if drastic changes are not made, climate change skeptics still make statements such as “global warming is caused by the sun” and “there is no scientific consensus Jowharspoke with climatologist Hervé Le Treut, who deconstructed these falsehoods.
If we don’t keep climate change below 1.5 degrees Celsius, the earth will be devastated by heat waves, hurricanes and storms, entire species will go extinct, and vast swaths of humanity will have to abandon their homes when coastal settlements flood. Such is the consensus among experts at the opening of COP26 in Glasgow on Monday.
Desperate to avoid this bleak future, people around the world have become active in taking action against climate change in their own lives, as well as urging politicians to act. Global warming has become the defining challenge of the 21st century.
Yet many people around the world still doubt or deny the terrifying and exhilarating reality of man-made climate change. Jowharpresented some of its most frequent claims to Hervé Le Treut, a climatologist at the Sorbonne University in Paris, the elite French Polytechnic School and the French Academy of Science.
True or false? “The weather has changed before, so it’s not a big deal.”
We have had a stable climate for 10,000 years. That is why we are specifically trying to protect the climatic conditions that have allowed humanity to develop during this period. The question is whether or not we want to continue the climate that has allowed human civilization to emerge.
True or false? “The sun causes global warming”
This idea has been repeatedly shown to be false. In fact, the sun’s radiation fluctuates, and sunspots vary in their activity levels. But these are fairly small variations that occur in relatively fast cycles (a typical cycle lasts 11 years).
However, scientists have observed many of these 11-year cycles and it is clear that these changes in the sun’s radiation cannot explain the increase in temperatures that we have seen in recent decades. The notion is impossible to defend scientifically.
True or false? “There is no scientific consensus on global warming”
We are faced with a complicated problem, and within that problem there is consensus in many aspects and controversy in some areas.
But it is a very clear fact that greenhouse gases are in the atmosphere and stay there for a long time, causing global warming. That is very easy to see when we look at what is happening to the planet. There is no doubt that there is a consensus on this.
You can tell how things are going just by looking at sea level rise, accelerating ocean warming, and melting glaciers; the direction of travel is obviously toward a warming planet. So it takes a lot of courage to say that there are no symptoms of climate change or that these symptoms are not clear enough.
True or false? “It’s very cold outside right now, and it was a little chilly at some points during the summer, so what global warming?”
This kind of argument is very boring because it is based on a misunderstanding of what climate change is and how it works.
We are dealing with systems created by human activity, as well as chaotic forces that operate in sometimes unexpected ways; that’s the nature of the weather. There are some forces at play that are easy to understand and anticipate; others are not.
Sometimes it is difficult to see proof of what is happening when you look at the weather on a small scale. But the big picture is clear: the number of abnormal phenomena that occur (floods, forest fires, etc.) shows how we cope with something that we have not seen before.
The problem with the weather is that we face unpredictable risks. Sometimes it is difficult to predict what the weather will be like for the next ten days. On the other hand, when you look at how things are changing around the world, it is obvious that we have no time to waste in the fight against climate change. During the last 50 to 60 years, we have seen very significant global warming, much stronger than natural fluctuations.
True or false? “The situation is not so serious; the IPCC is too alarmist ”
The IPCC report [released in August] It was produced by the unanimous agreement of all the countries subscribed to the United Nations Framework Convention on Climate Change. That’s many countries [197, to be precise].
So there is a very strong unanimity, which makes it difficult to accuse the IPCC of saying the wrong thing.
True or false? “People, animals and plants will be able to adapt”
We have only seen the beginning of the climate change process. Science shows a clear effect of greenhouse gas emissions as a cause of climate change. It is a process that began in the 1970s, became visible in the 1990s, and is accelerating exponentially. As things stand, what will happen in the future is a continuation of what is already happening. We are at a stage where global warming continues and we know why, because it is caused by causes that scientists have been able to observe with precision.
Humans will have a greater capacity for adaptation than other species. But the world is now very populated. Previously, when humans adapted, that meant moving. But now the migration is not so easy; there are borders, there are rules. Therefore, there is a great risk of conflicts related to migration. Humans will only be able to adapt if we allow people to move away from the worst affected areas, and that is not the case today.
With regard to plant and animal species, we are seeing a very steep drop in the numbers of most species in most countries. There is much documentation that points to how so much biodiversity is disappearing, often related to forms of agriculture that are harmful to the environment, in addition to greenhouse gas emissions.
So from the evidence we see today, it’s pretty clear that species adaptation is not happening.