The above video covers over 100 years of climate science. It shows how scientists began making serious warnings about global warming in the 1950s and that these warnings began to intensify during the 1970s and 1980s. It also shows that the scientists were absolutely correct in their estimates of temperature increase.
However, the most chilling aspect of this video is it shows that scientists greatly underestimated the degree of response from the world’s ice sheets and other key climate indicators and feedbacks. One such instance is displayed by early scientific estimates of sea ice melt.
In the above figure, we see IPCC model runs on Arctic sea ice melt (shown in black) compared to actual arctic sea ice melt (shown in red). As with other observations, the response from sea ice to human heating has been much more sensitive than the response estimated by scientists. What one can extrapolate from this is that the entire climate system is probably much more sensitive to forcings than what scientific estimates and models show.
But what is most concerning about the video is that, despite over six decades of warnings from scientists, civilization has yet to make serious efforts to curtail greenhouse gas emissions. Now time is growing short and we have already locked in a certain degree of damage from human-caused climate change. Wait another decade or two and there probably won’t be much chance to stop some very, very tough consequences.
The video concludes with a stark statement by Dr. MacCracken:
“I have a colleague who went home very discouraged to her 13-year-old daughter. And her daughter just heard this disappointment and all this stuff, and basically said to her mother, “You can’t take away my hope.” I think we have an obligation to try to find a path.”
Though I agree with the statement by Dr. MacCracken, I believe, like most statements from scientists, that his words are entirely too moderate. I think that, if we were to set in place a series of events that would wreck the climate system for our children and grandchildren, then we would be nothing short of the most monstrous human generation who has yet lived. And, if humans survived such a self-inflicted trouble, they would rightly view our generation with even far greater ire than the most hated and feared tyrannies of human history. We will be seen as they ones who wrecked their prospects, who created the conditions that resulted in so much harm. And we would entirely deserve this hatred and ignominy.