True or false? Exposing the falsehoods of climate change sceptics

A child runs as climate change activists gather to protest outside of BlackRock headquarters in San Francisco on October 29, 2021, ahead of the COP26 climate summit in Glasgow.
A child runs as climate change activists gather to protest outside of BlackRock headquarters in San Francisco on October 29, 2021, ahead of the COP26 climate summit in Glasgow. © Carlos Barria, Reuters

As the COP26 climate summit gets under way in Glasgow amid apocalyptic projections if drastic changes are not made, some sceptics still insist that climate change is "natural" or that there is "no scientific consensus” on global warming. FRANCE 24 spoke to climatologist Hervé Le Treut, who helped deconstruct some of these falsehoods. 


If we do not keep climate change below 1.5°Celsius the earth will be ravaged by heatwaves, hurricanes and storms, entire species will become extinct, and vast swaths of humanity will have to leave their homes when coastal settlements are inundated. Such is the consensus among experts as the COP26 opens in Glasgow on Monday.

Desperate to avert this grim future, people throughout 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. 

Nevertheless, many people throughout the world are still doubtful or in denial about the terrifying, galvanising reality of man-made climate change. FRANCE 24 put some of the most frequently heard claims to Hervé Le Treut, a climatologist at Paris’s Sorbonne University, France’s elite Polytechnic School and the French Scientific Academy. 

True or false? The climate has changed before so it’s not a big deal

We’ve had a stable climate for 10,000 years. So we’re 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 with the climate that has allowed human civilisation to emerge. 

True or false? The sun causes global warming

This idea has been repeatedly shown to be untrue. The sun’s radiation does indeed fluctuate, with sunspots varying in their levels of activity. But these are quite small variations that occur in relatively rapid 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 can’t account for the increase in temperatures we’ve seen over the past decades. The notion is impossible to defend scientifically. 

True or false? There is no scientific consensus on global warming

We’re faced with a complicated problem, and within that problem there’s consensus on a lot of aspects and contestation around some areas. 

But it’s a very clear fact that greenhouse gases are in the atmosphere and stay there for a very long time – and that they cause global warming. That’s very easy to see when we look at what’s happening to the planet. There’s no doubt there’s a consensus on that. 

You can tell how things are going just from looking at rising sea levels, the accelerating warming of the oceans and the melting of glaciers – the direction of travel is obviously towards a warming planet. So it takes a lot of nerve to say there are no symptoms of climate change or that these symptoms aren’t clear enough. 

True or false? Severe cold, or chilly weather during the summer, belies global warming

This type of argument is very boring because it’s based on a misunderstanding of what climate change is and how it works. 

We’re dealing with systems created by human activity as well as chaotic forces that operate in sometimes unexpected ways – that’s the nature of the climate. There are some forces at work that are easy to understand and anticipate; others are not. 

Sometimes it’s hard to see proof of what’s going on when you look at the weather on a small scale. But the big picture is clear: the number of abnormal phenomena going on – floods, wildfires etc – show how we’re confronted with something we haven’t seen before. 

The problem with the climate is that we’re facing unpredictable risks. It’s sometimes hard to predict what the weather’s going to be like over the next ten days. On the other hand, when you look at how things are changing across the world, it becomes obvious that we’ve got no time to waste in combating climate change. Over the past 50 to 60 years, we’ve seen very significant global warming – much stronger than natural fluctuations. 

True or false? The situation isn’t all that serious and the UN's recent IPCC climate report is alarmist

The IPCC report (from the Intergovernmental Panel on Climate Change, released in August) was produced by the unanimous agreement of every country signed up to the United Nations Framework Convention on Climate Change. That’s a lot of countries (197, to be precise). 

So there’s very strong unanimity, which makes it difficult to accuse the IPCC of saying anything incorrect. 

True or false? People, animals and plants will just be able to adapt

We’ve only seen the start of the process of climate change. Science shows a clear effect of greenhouse gas emissions in causing climate change. It’s a process that started 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’s already happening. We’re at a stage where global warming is continuing and we know why – because it’s produced by causes that scientists have been able to observe accurately. 

Humans will have a greater ability to adapt than other species. But the world is now very crowded. Previously, when humans adapted, that meant moving. But now migration is not so easy; there are borders, there are rules. So there’s a big risk of conflicts linked to migration. It will only be possible for humans to adapt if we let people move away from badly affected areas – and that’s not the case today. 

With regard to plant and animal species, we’re seeing a very sharp drop in the numbers of most species in most countries. There’s a lot of documentation pointing to how so much biodiversity is disappearing – often related to environmentally unfriendly forms of agriculture in addition to greenhouse gas emissions. 

So it’s quite clear from the evidence we’re seeing today that the adaptation of species is not happening. 

This article has been translated from the original in French.

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