It was...
a great joke. I am still laughing today.
They fabricated data to support man/bear/pig in the 20th century, but chose to ignore 200,000 years of data that says the world has gone through several cycles of hot and cold weather in recent history.
The global temperatures we have now are almost 10 degrees below what they were during the Medieval Warming Period (800 ad to 1300 ad). Where were the factories, planes or cars to warm the earth then? What warmed the planet then when the global population was a tiny percentage of what it is today?
By ignoring the past we miss the chance to see the real causes of global warming are out of our hands. Mother Nature rules?