User Reviews

"Polar Extremes" (2020 release; 115 min.) is a documentary about the drastic changes that Planet Earth is currently undergoing at both the Arctic and Antarctica. As the documentary opens, we get to know Kirk Johnson, Director of the Smithsonian's National Museum of Natural History, and of course a scientist (as in: paleontologist). Johnson gives a 30,000 ft. big picture introduction as to the overall situation, and then takes us on a global journey to look for the facts as they are buried (and waiting to be found) in nature itself.

Couple of comments: as to the documentary itself, it literally takes us on a global journey to seek answers as to what is happening to Planet Earth's climate: we go to both the North Pole and the South Pole (of course), but also a number of places in the US, Canada, Russia, Greenland and elsewhere that can shed light on these issues. The amazing thing is that the scientific evidence is there to be found, and then explained to us by Johnson and others in a way that we can relate to, without being lectured to or patronized a la Al Gore's "An Inconvenient Truth" documentary, as big a turn-off as there ever was in the climate change debate. As to that climate change debate: I'll admit that I have been skeptical about the argument that this is all a result of man-made activities. Here's the beauty about this documentary: first, it reminds us that it's been 3 million years since there has been that much carbon dioxide (CO2) releases in the earth's atmosphere, and we then get a close review what the earth was like back then, giving us an indication of what we can expect. Second, the earth's climate does evolve naturally over the millions of years (causing the ice blankets from the poles to expand drastically and then to reduce drastically over thousands and thousands of years), but the current changes are coming at a far quicker pace than the prior natural evolution, and in fact can be traced back to the last 150 years or so (around when the industrial revolution took off).

"Polar Extremes" premiered last week as the season opener of NOVA on PBS, and is now available on demand and on streaming services, with a DVD release coming in May. If you have any interest in what is causing the earth's climate to evolve over the thousands and millions of years, and what is happening today, I'd readily suggest you check this out, and draw your own conclusion. Even if you don't agree with some or all of the findings presented in this documentary, I am quite certain that you will nevertheless find it compelling viewing. HIGHLY RECOMMENDED!

The posted "Storyline" on this webpage does a good job to describe this episode's content. The abundant flow of facts and research presented is above average, and therefore very satisfying. There are instances when a string of findings and facts are presented, then a conclusion is presented as yet another fact rather than as a hypothesis. What has happened with the study of climate on Earth (like with the discovery of supermassive black holes, or the string of findings that have led to hypotheses of dark matter and dark energy, etc.) is a mixture of facts and the theories we assemble from them; and they must be subject to ongoing research and discovery (like what is ongoing with the research of supermassive black holes, dark matter and dark energy).

Here's one example. As has been done elsewhere, this NOVA episode presents the irresistible comparison of the runaway greenhouse on the planet Venus and its components (e.g., carbon as the greenhouse accomplice) against reported current era carbon increases on Earth to draw towards a conclusion that we're on track to a similar state of affairs, though (clearly) Earth need not resemble Venus closely to become barren and lifeless. However, there is no mention of the fact that the length of one day on Venus is 243 Earth days. What would happen on Earth if one day lasted two-thirds of a year (as on Venus), given the swing in temperature on Earth in a single 24 hour period? Starting tomorrow, if the Sun could concentrate its energy on the surface of the Earth for months (without night to cool things down in a regular 24 hour period), a cycle towards a greenhouse scenario resembling Venus would be well underway. Further, with oceans begining to turn to water vapor there would be increasingly no "sink" for the emissions from volcanoes other than the atmosphere, so the greenhouse effect would gain momentum in such conditions. There are other factors to add to discount Venus as a cautionary tale for Earth beyond anecdotal, but the above is enough to make the point.

There's perhaps one compelling sequence that stands out in all the data presented in the episode: the chart of "hothouse worlds" (no ice) and "icehouse worlds" (with icecaps at least at one of the poles, and colder)-a timeline of the Earth's climate history over the last 500 million years showing, again, the range of temperature and the epochs where at least ice caps existed. It turns out that only 25% of our climate history resembles the climate profile we enjoy today, and the other 75% being much warmer. This is an extraordinary piece of evidence that demands extraordinary (not simple) conclusions, such as is often said in popular media: just reduce human-generated atmospheric carbon and we'll be OK. To his credit, the host-Kirk Johnson, who holds a doctorate in geology and paleobotany from Yale University-takes the opportunity to assert: "Today we live on a planet that has ice at both poles, and we think that's normal because that's our world-but when we look at the fossil record we realize that it has had only four episodes where there's been glacial ice-only about 25% of the last 500 million years has our planet been like it is today."

Another example (without mention in the episode): "The Little Ice Age"-roughly from the middle ages to the early to mid nineteenth century. There are theories, but none with overwhelming consensus, i.e., no one knows what started the warming period that caused the end of that cooled epoch, but it's clear that given the end came before or during the infancy of the industrial revolution, there is far too little human intervention to conclude that the new warming was man-made.

Anyone reading the above may think that this review is inspired by a streak for denying "climate change"-it is not. It is the want for engaging science-which doesn't call for "believers" and excommunicate "deniers"-it simply carries on its endeavor, building the body of evidence, and humbly refining its theories as the entire (not agenda-selective) body of evidence grows. Net-net, this episode comes out on the plus side of that criterion.

This movie is a beautiful story tell of the earth life and close future that we can expect. I love it, it's a wonderful way to understand all changes and what we can expect from our planet and what we can do to help it.