It's interesting to speculate what Attenborough would say if he realized the lecture he saw was built on a lie. The article makes it clear that what converted Attenborough was the NASA GISTEMP graph. It would never have occurred to him to ask whether this data was being manipulated.

The graph he saw is this one:

https://www.carbonbrief.org/wp-content/uploads/2018/08/atten...

Go to the NASA GISTEMP website (https://data.giss.nasa.gov/gistemp/graphs_v4/) and look at the same graph as it is today. There are differences between the two. For example in the graph he saw, the temperature anomaly in 1981 is about 0.21 degree C. In the current graph it's 0.32 degree C.

It's a little known fact that the organizations producing graphs of global temperatures continually rewrite the historical record and often do so silently. These rewrites create warming trends in the data where in the past no such trends were visible. This article proves the case beyond doubt:

https://realclimatescience.com/rewriting-the-climate-at-nasa...

It shows two different graphs claiming to be the same version of the same temperature dataset, both on the NASA website. One is no longer linked from anywhere and can only be reached because the blog author preserved the link in his records. They have different data in them - the newer one shows more warming during the 20th century than the older one.

The head of climatology at NASA was challenged on Twitter to explain why historical data was being silently rewritten. His only response was a clown face emoji.

As you go further back into the past the edits become ever more extreme. The lecture notes admit that there was a "slight cooling" between 1940 and the end of the 1970s. The NASA temperature graphs show that global temperatures went sideways during this time - something that makes no sense given that the climatology of the era was dominated by fear of global cooling, nor if all the increase is caused by CO2 because CO2 levels increased steadily during this era (the lecture says it's a mystery).

Newspaper archives show that in the past, scientists had a very different view of what temperature was doing. Back then the National Center for Atmospheric Research showed global temperatures experiencing a strong multi-decade decline from the 1940s to the 1970s, with the temperature in 1973 being no different to the temperature 1910. Nowadays climatologists claim that the early 20th century were some of the coldest years on record with 1913 being a full half a degree colder globally than in 1973.

Climatologists don't deny that they do this, but as NASA's reaction shows they don't like people knowing about it. Over the last 20 years the field's approach to data integrity has collapsed completely and with predictable results - nothing can now be said about global temperatures with any certainty. Even basic things like announcing record breaking temperatures is no longer possible because the past is always being rewritten:

https://retractionwatch.com/2021/08/16/will-the-real-hottest...

> "NOAAGlobalTempv5 is a reconstructed dataset, meaning that the entire period of record is recalculated each month with new data."

Changing past "observations" every time new data is recorded is scientifically nonsensical. The future cannot change the past.