Is Anyone Really Sure About Climate Change and How Do They Know?

Mention of scientific agreement about climate change evokes an image of an amorphous group of scientists who’s individual opinions are more or less in agreement. In fact scientific agreement on climate change is organized and formally established, and has been for decades.

There is one organization towering above all others when it comes to being the definitive authority on climate change. That organization is the Intergovernmental Panel on Climate Change, also known as the IPCC.

No one else even comes close.

No other individual or organization takes the time or makes the effort to scour the whole world for the latest scientific papers relating to all aspects of climate change.

The IPCC does that for each of their many reports.

Many thousands of peer reviewed scientific papers and other information are brought together, evaluated and assessed in order to summarize the current state of world knowledge.

No other individual or organization makes use of scientists and experts, and government representatives, and interest groups from all over the world just to select who the authors of each report will be.

The IPCC does that.

There are 195 member nations of the IPCC and more than 100 organizations with observer status.

Member nations include countries whose entire economies are wholly dependent on the production and sale of oil, coal and/or gas; the main contributors to climate change.

Member nations also include countries whose very existence is threatened by climate change, such as small island nations that will disappear under the waves of sea level rise.

195 member nations means just about every nation in the world, including yours.

Observer organizations include both environmental groups and business lobbies.

All of these countries and groups have a say in who the hundreds of scientists are that will author an IPCC report.

No organization other than the IPCC draws on the expertise of thousands of scientists from all around the world who volunteer their time for years for the honor and prestige of participating in such an important endeavor.

No other organisation requires the formal consensus of virtually every expert on earth before releasing it’s scientific reports. The IPCC does.

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No other organisation requires the formal consensus of virtually every nation on earth before releasing it’s reports. The IPCC does.

Not only does it call on all those experts to contribute the initial information, but once the draft report is written it calls on the experts of the world to submit their constructive criticism. In preparing the IPCC’s Fifth Assessment Report which eventually came out in 2014 the authors received more than 140,000 reviewer comments, every one of which they were required to take into account.

After reviewer comments are accounted for, the IPCC convenes plenary sessions where scientists, governments and observer groups review the documents line-by-line and word-by-word to ensure consesnsus.

No other organisation can claim to produce reports of scientific findings on climate change that represent an official consensus of the world’s scientists and the world’s governments.

What’s the Conclusion?

IPCC reports are thousands of pages long and cover every imaginable aspect of climate change. They portray what is known and the degree of certainty with which it is known as well as the degree of agreement on what is known.

The IPCC is certain that climate change is happening. The world is heating up.

The IPCC is also sure that the changing climate is happening almost exclusively because of what humans have been doing to the atmosphere.

In the wake of the 2015 Paris Agreement the IPCC evaluated how much difference it would make to the world if we stopped warming at 1.5C instad of at 2C. The IPCC concluded that the difference would be enormous.

For more info on the IPCC — in a digestible form — check out the book Because IPCC.

It’s a short, 33 illustrated pages, an upbeat, entertaining story that explains the history and science of the IPCC. The scene is 100 years in the future when the world has “solved” climate change and people are looking back, inspired by the dedication, rigor and achievements of the scientists of today.


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