Five myths about climate change

Paris, France | As COP26 approaches, AFP Fact Check is reviewing some of the most common claims to question human-caused global warming.

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ploy or conspiracy

For some, the climate crisis is just a construct for scientists to justify their funding, or even a conspiracy by governments to control people. This may presuppose an organization of unprecedented complexity, coordinated by successive governments in a large number of countries with the complicity of a veritable army of scholars.

However, tens of thousands of studies, each time revised and corrected by other scientists, have led to an almost unanimous consensus on the reality of human-caused climate change. Far from being secret, this process is illustrated by the work of the Intergovernmental Panel on Climate Change, which is open to all UN member states.

Created in 1988, the 2007 Nobel Peace Prize, this intergovernmental panel on climate change brings together, on a voluntary basis, hundreds of scientists reviewing the state of knowledge with a methodology and general references, to find www.ipcc.ch

Its most recent 3,500-page report, published in August, was written by 234 authors from 66 countries and endorsed by delegates from 195 countries.

The climate has always changed

Planet Earth has a long history of alternating periods of glacier and warmer periods, with about one glacial occurrence every 10,000 years. So, is the current period of warming just another phase in this cycle that has lasted for about a million years?

No answer for experts, because the speed, amplitude and global nature of the current warming make it exceptional. “Since 1970, global temperature has increased faster than any other 50-year period in the last two millennia,” the Intergovernmental Panel on Climate Change asserts, based on weather records (since its existence) and studies of sediment, ice core or other previous elements. . periods.

Human causes have not been proven

As evidence of warming is accumulating, some question its human origin, and greenhouse gas emissions from human activities since the fossil fuel-based industrial revolution.

The Intergovernmental Panel on Climate Change has developed a model to measure the effects of various factors on global warming. The Intergovernmental Panel on Climate Change wrote in a “Summary for Decision Makers” in its latest report published in August (pp. 7 and 8 of this document, in English. https://u.afp.com/wZ6N).

A little heat can’t hurt

“A large part of the country has a massive amount of snow and hail near the logs… A little bit of this good old warming wouldn’t hurt!”

On January 20, 2018, the notorious then-President of the United States, Donald Trump, posted on Twitter this supposed common-sense idea: If the planet is warming, why are there always bouts of extreme cold?

But the climate and its changes can be observed in the long term, while weather phenomena have their own and more urgent mechanisms, even if some of them can be exacerbated by climate change.

And the warming of icy Siberia will not only have advantages. Permafrost, a layer of permanently frozen soil, contains huge amounts of greenhouse gases that would be emitted from its thawing, not to mention potential viruses…

A world at +2°C compared to pre-industrial times would raise sea levels by half a meter or more, threatening millions of people living in coastal areas.

Scientists question the reality of climate change

Some have expressed doubts on the forums, but in general, these are not climatologists. Historically, scientific knowledge is built by argument, followed by consensus building on knowledge.

And on climate change, that consensus is now overwhelming. According to a very recent study by Cornell University in the United States, more than 99% of articles on climate change published since 2012 by peer-reviewed scientific journals agree in attributing this phenomenon to the consequences of human action (https://u.afp.com/wZ6p).

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