Climate knowledge is robust

If it looks like a goat and smells like a goat…

What is credible knowledge? What makes you believe the information you see or read? Would you believe something you saw with your own eyes?

What about word of mouth from a trusted friend? How about word of mouth from a stranger?

What about something in text book?

What about a random article on the internet?

It’s the 2020s and the internet has lowered the cost of entry to those wishing to challenge established media. Further, public trust in media is at historically low levels and as a consequence, traditional media is being outperformed by alternatives.

Ideas that were long perceived as false, such as flat-Earth theory, appear to be spreading in popularity.

With this in mind, it has probably never been more difficult to mount a public campaign to mobilise support for action to mitigate climate chance.


Amidst the fog, there are certain attributes which tell us if information is credible or not. Two such attributes are how technical the information is and the level of critique or how much it has been reviewed by others.

The Holy Grail of credible information is peer reviewed literature, where a version of a researcher’s findings is anonymously reviewed by others in the same field to help decide whether it should be accepted and published.

There are those who question established science—on climate science or any other matter. The ability for them to put forward these findings and for others to review them is a vital part of academia’s self-regulation and improves quality overall.


The IPCC is made up of scientists who volunteer their time to get together, review each other’s peer reviewed literature and publish their findings. It does not conduct original research, but produces assessment and reports based on existing knowledge. The most recent cycle involved over 700 scientists from 90 countries.

The IPCC has published five comprehensive reports—in 1990, 1995, 2001, 2007, 2014. A sixth is due in 2022.

To begin, a first draft of a report is prepared by the authors based on scientific, technical and socio-economic literature in scientific journals and other relevant publications. There are usually thousands of citations.

The First-Order Draft is reviewed by experts. Any expert can register as a reviewer.

After the review, a Second-Order Draft is prepared, which is reviewed by experts and governments.

Following receipt of the review comments, author teams then prepare a final draft.

The final draft is distributed to governments for a final round of written comments, before governments meet in plenary session to approve the Summary for Policymakers line by line and accept the underlying report.

The drafts are not made public before the final document is approved because they may not yet meet IPCC quality and accuracy standards. However, at the end of the process the First and Second-Order Drafts are made publicly available, along with the reviewer comments and the responses of the author teams to all comments, when the final reports are published.

Consensus building

It could be said that the IPCC has underestimated real-world observations for emissions, temperature, sea-level rise and other effects. It is almost silent on tipping points.

The reasons are twofold. Firstly, the IPCC publishes major reports every five years or so, but new science is published all the time, so what’s being reported on is likely to be behind the latest science.

The second reason is due to the need for line-by-line approval, i.e. consensus.

Can you imagine almost 200 countries agreeing on every line of a document, particularly when the document will help or hinder countries’ future negotiating positions?

It has been argued that getting everyone to agree dilutes the scientific findings of the report. It’s easy to see how this can draw something towards its lowest common denominator.

The IPCC’s Second Assessment (page 30) states:

In reality, the Greenland ice sheet is melting to a point where it poses a risk for coastal communities and Arctic sea ice is declining faster than forecasted.

If you run a thought exercise on consensus-based decision-making, it’s easy to see why.

Let’s imagine a room full of 200 random people with a whiteboard up the front and they are tasked with developing an agreed statement on nuclear energy.

Someone stands up and writes the following:

A second person disagrees, and makes the following edits:

After a week of back and forth, the 200 people emerge. They have finally agreed on a statement on nuclear energy.

How can you make any definitive assessments or effective policy based on the above statement? It’s more agreeable, but it’s inherently more conservative as it falls short of making any definitive statement.

While the IPCC tends to be more aligned on scientific observations than the example above, you can see how headline statements within reports are likely to be softened in order to gain support.

A final word

Given the large number of personnel involved, the review process and the need for consensus, it is hard to defend the assertion that these reports are politically motivated, one-sided or exaggerating the projected effects of climate change.

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