On the eve of COP26, which will take place in Glasgow, AFP reviews some frequent statements that question climate change caused by human activity.
1. Plan created or plot
Some think the climate crisis is an idea created by scientists to justify funding science. Others believe it is a plot by governments to control the population. Something that would require a plan of unprecedented complexity, coordinated by successive governments from different countries with the complicity of an army of scientists.
But, on the contrary, the almost unanimous consensus on the existence of climate change of anthropogenic origin was built on tens of thousands of studies (reviewed and corrected by other scientists). In addition, as a form of transparency, works such as the Intergovernmental Panel on Climate Change (IPCC) are open to all UN countries.
Created in 1988, winner of the Nobel Peace Prize in 2007, the IPCC brings together hundreds of volunteer scientists who review the state of knowledge based on a method and public references, which can be consulted on the group’s website.
Its most recent report, published in August, with 3,500 pages, was written by 234 authors from 66 countries and approved by delegates from 195 states.
2. The weather has always changed
Since its inception, planet Earth has alternated between very cold and warmer periods, with an ice age roughly every 10,000 years. So can’t the current warming period be considered another step in this million-year cycle?
For experts, the answer is clear: no. The speed, magnitude and global character of the warming we are experiencing is exceptional.
“Since 1970, the world temperature has increased faster than in any 50-year period in the last two millennia”, highlights the IPCC, from meteorological records (since they have existed), sediment studies, samples extracted from ice (testimonies) and other elements for more recent times.
3. Human influence is not proven
Despite mounting evidence of warming, many people question whether it is caused by human activity, such as greenhouse gas emissions, which have increased since the industrial revolution through the use of fossil energy.
The IPCC has developed a model to measure the impact of different factors on global warming. “There is no doubt that human influence has warmed the atmosphere, oceans and land,” writes the IPCC in its “summary for policymakers” in the panel’s most recent report, published in August (pages 7 and 8, in English).
4. A few more degrees can’t be a bad thing
“Much of the country is under a huge amount of snow and has record cold temperatures… some of the old-fashioned global warming wouldn’t be bad.”
On January 20, 2018, Donald Trump, president of the United States at the time and skeptic of climate change, tweeted an idea of ​​supposed common sense: If the planet is warming, why are there still episodes of intense cold?
Climate evolution, however, is observed in the long term, while meteorological phenomena have their own mechanisms, more immediate, including because they can be aggravated by climate change.
And that certain regions of the world are experiencing warming, such as Siberia, is not good news. Permafrost, the permanently frozen ground layer, captures large amounts of greenhouse gases that would otherwise be released into the atmosphere if it melts. Not to mention the possible existence of retained viruses…
A world with +2°C compared to the pre-industrial era would cause a rise of half a meter in sea level, which endangers the lives of millions of people in coastal areas.
5. Some scientists question the reality of climate change
Although there are scientists who express doubts in public articles, in general they are people who are not climate specialists. Historically, scientific knowledge is built on controversy, followed by consensus based on existing knowledge.
As for climate change, this consensus is large. According to a recent study by Cornell University (USA), more than 99% of articles on climate change published since 2012 in scientific journals (peer-reviewed) agree with the attribution of the phenomenon to human action.
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