Top 20 TED Talks on Climate Change Ranked by AI

Finding something good to watch is hard. It’s a lot like looking for something good on Netflix. If you’re anything like me, you probably spend longer scrolling through your options than you do actually watching the program! I was looking through TED this week for something new to watch about climate change but I just got lost. I didn’t want to watch a talk just because it had a lot of views – I wanted to find the hidden gems too.

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Of the thousands of official talks on tagged with the word “climate” there are 1,149 results. I then started wondering if I was to invite the best speakers over to dinner, who would I invite? Or if I wanted to share some talks to help entertain and educate my friends, which ones would I recommend? I thought it was a good question worthy of a good answer, so I turned to AI in the form of IBM Watson to help me find the best TED talks on climate change. Watson is simply a natural language processing engine which can analyse up to 500GB of ‘un-structured data’ every second and create useful insights from it – in this case, video, speech and text.


“The only thing that truly matters in public speaking is not confidence, stage presence, or smooth talking. It’s having something worth saying.” Chris Anderson, Head of TED


The TED site has a curated playlists already but I wanted to look a little bit deeper, and use some science to help me find the best talks. The ones that would really challenge and inspire you. I’ve watched a LOT of TED talks on climate change and I was VERY surprised by the final rankings.


There are over 2,600 talks on and an estimated 50,000+ talks which have taken place at TEDx events throughout the world. At an average of 18 minutes each (or around 2,500 words) that is a LOT of content. A human would take years to analyse that much content. But at IBM we have worked on a project with TED to help curate some of these talks and to use AI to help highlight some of the best insights from each talk. We just ran a similar project at Cannes earlier in 2019.


IBMs AI (called IBM Watson) can not just search the videos for specific clips when the speaker mentions a certain topic, but using a natural language tool called ‘Personality Insights’ it can measure levels of trust, love, anxiety, fear, emotional range, authority challenging, intellect, helping others and practicality. I thought this would be a really useful tool to help me find the talks which were really the ones I had to watch – not just the most famous ones with the most views.




“If you want to change the world you need to break the rules”. Greta Thunberg


Measuring the “personality” of each talk according to it’s ability to “challenge authority” seemed to me the ideal way to discover the best talks on the climate crisis (not just because it is one of the principles at the heart of the Extinction Rebellion movement – which I like a lot), but because the need to ‘speak truth to power’ and inspire governments to act has never been great.


“In the end people are not persuaded by what you said, but by what they understand”. John C. Maxwell


In many cases, the climate crisis is as much a natural security, and healthcare issue as it is an environmental one – so we need to tell emotional (but factually correct) stories to people in a language that they can understand. What you will see from the analysis of each TED talk, perhaps not surprisingly given the topic, is that the levels of intellect and the desire to challenge authority are incredibly high. I also looked at the emotional range of each talk and measured it against the audiences reaction – but like IBM Watson measures the excitements level of the crowd for Wimbledon. You can read about the science and how I worked out all the rankings below.


“After the final no there comes a yes. And on that yes the future depends”. Al Gore (Quoting Wallace Stevens)


So I made this short list of the best climate change talks to watch to challenge and inspire you. You will see from the analysis made by IBM Watson how an artificially intelligent natural language processor ranked each talk, taken either by using speech-to-text technology or from the talk transcript on


Enjoy watching.


The Top 20 TED Talks on Climate Change: Analysed by IBM Watson


20. The Case For Optimism On Climate Change – Al Gore




19. Why I Must Speak Up About Climate Change – James Hansen




18. Seeking Salvation And Profit In GreenTech – John Doerr







17. Let’s Prepare For A New Climate – Vicki Arroyo








16. A Critical Look At Geo-Engineering Against Climate Change – David Keith




15. The State Of Climate And What We Might Do About It – Lord Nicholas Stern




14. Global Priorities Bigger Than Climate Change – Bjorn Lomborg









13. Climate Change Is Happening. Here’s How We Adapt – Alice Bows-Larkin




12. The Disarming Case To Act Right Now On Climate Change – Greta Thunberg




11. The Emergent Patterns Of Climate Change – Gavin Schmidt






10. How Empowering Women And Girls Can Help Stop Global Warming – Katharine





9. The Science Behind A Climate Headline – Rachel Pike




8. New Thinking On The Climate Crisis – Al Gore




7. The Earth Is Full – Paul Gilding




6. The Most Important Thing You Can Do To fight Climate Change: Talk About It – Katharine Hayhoe




5. How To Transform Apocalypse Fatigue Into Action – Per Espen Stoknes




4. Time-Lapse Proof Of Extreme Ice Loss – James Balog




3. Averting The Climate Crisis – Al Gore




2. Why Climate Change Is A Threat To Human Rights – Mary Robinson




  1. The Inside Story Of the Paris Climate Agreement – Christina Figueres




The Science

Using AI for an exercise like this makes things a lot easier. IBM Watson is a natural language based system which can watch every talk, understand the speech, convert it to text, and then analyse it for different emotional qualities – previously being trained to understand this by psychiatrists, and then using its processing power to compare and contrast against different talks.


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Based upon the talks which IBM Watson measured to have the highest likelihood of “authority challenging” and “intellect”, I ranked them according to which ones where the most provocative and intellectually stimulating. A crude methodology for sure, but I wasn’t convinced a complex weighted algorithm would deliver anything more significant. not in terms of which ones are the most educational and entertaining. I didn’t want to rank based upon “authority-challenging” alone, because anyone can challenge authority, but it doesn’t mean that they have a valid case. And it is not unreasonable to assume if that same argument has a very high level of “intellect”, then it is likely to be a point of view that is well thought through point of view, rooted in some form of scientific evidence.


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I included “emotionality” since the component of any great talk is to tell stories through drama, emotion, tone and by adding sentiment. And lastly, I measured the ratio of applause and laughter to time spent talking, not for any scientific reason, but just to compare audience engagement. Just like a comedian seeking a laugh every 12-30 seconds, or a presenter aware that an audience attention usually drops after about 6 minutes – the lower an applause rate the better. The higher the score – the longer between laughs or applause. I am acutely aware though that we are talking about climate change here (and many of the talks are more like lectures to educate rather than talks to entertain), so I saw in many of these talks lower levels of engagement than you would normally expect, simply because it is such a serious topic. It does also show the great need to make some of the data more compelling or to break it up in a way that is accessible to the audience.


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The personality insights traits I have used often referred to psychiatrists as “the big 5” [LINK: The Science of Personality Insights] – meaning that they are used to understand how a person engages with the world. But just to be fair, I also included one of the human “needs” from the personality trait measurement, because these are understand by researches to be the traits which directly influence human behaviour – so I asked Watson to show me the structure of each talk.


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Personality models are a well-accepted theory of psychology, marketing, and other fields is that human language reflects personality, thinking style, social connections, and emotional states. The frequency with which people use certain categories of words can provide clues to these characteristics. My hypothesis was that using a personality model like this to analyse each TED Talk would be ideal, since we are comparing the language on such a complex, emotional and political topic.


You can try the IBM Watson Personality Insights Demo Here


<< In episode 27 of my TenWords podcast I did a deep dive into the TED Talk that made Greta Thunberg famous and helped to launch her Friday’s School Strike as she was nominated for a Nobel Peace prize. You can listen to it here or find it on Apple podcasts >>


** NOTE: Any ranking is arbitrary and biased in one way or another, and this list is no different. AI systems like IBM Watson require a corpus of information in order to conduct accurate analysis. We often refer to this as a confidence level to which the system believes that the analysis is accurate, and as a rough rule of thumb, we prefer around 6,000 words of dialog to deliver a high degree of confidence. In the case of TED talks which are usually less than 20 minutes, this means Watson is only analysing a transcript of around 2,500 words or so. For this reason, while this exercise is a lot of fun and enjoyable to compare talks, I would encourage you not to read too much significance into the back-of-the-napkin analysis that Watson and I conducted. It’s just a bit of fun to entertain and educate you.


The TED site also has a few curated playlists already which you might like: