This is the most comprehensive overview on global warming I have seen. I was already familiar with much of the material from a lot of reading over the years. But the orderly presentation and repeated use of the global temperature time line for the past 650 million years helped greatly to bring all this information into focus. It also corrected some confusion I had between the warming 250 million years ago associated with the Siberian Traps eruptions and the warming 56 million years ago at the PETM.
Changes seemingly associated with global warming have been occurring at an increasingly rapid pace in recent years, as has the advancement of our scientific understanding, so there is a danger these documentaries could become out of date quickly. That has not happened with A Global Warning?, in part because it includes the dramatic melting of Arctic sea ice in 2007, a key tipping point. What has happened since has mainly been more of the same, and faster. The documentary mentions the record number of tornadoes in the U.S. several years ago, and yet this past year eclipsed that record and saw many other weather extremes. It sure looks like a global warning.
One reason you should watch this is because it talks about the importance of methane as a greenhouse gas 26 times more potent than CO2. It shows where the methane is being released, including off the coast of California, as well as Alaska. It could have done a better job of explaining the importance of methane and the clathrate gun hypothesis, such as the risk of a vicious cycle or increasing temperatures and methane hydrates release, or that methane breaks down into CO2, continuing to cause damage in its afterlife. But it clearly shows the methane bubbles reaching the ocean surface, contrary to what some optimists believe.
This documentary is an excellent starting point, and an excellent review for those who have already been following the subject. It largely avoids being sensationalistic, letting the facts and experts speak for themselves. So on the one hand, it can be a bit dry and a tad boring, so you must keep your attention focused, or you will miss things. On the other hand, once the facts sink in, the inescapable conclusions are plenty sensationalistic.
Are we in deep trouble? It certainly seems so, though the documentary avoids such editorializing. Is there anything we can do? This it does not address, beyond one expert saying we still have some time to act, which may be optimistic. How much warming -- 2 degrees F, 2 degrees C, 5 degrees, 9 degrees -- is enough to wreak eventual havoc? This is not spelled out, either, perhaps wisely, because this estimate seems to be changing with further analysis.
How much time we have again is not spelled out. But one of the most shocking facts was that the earth warmed rapidly in a matter of decades 11,500 years ago, due to natural causes, bringing us out of an ice age. On the Greenland Ice Sheet, scientists calculate the temperature rose 18 degrees F. in just a decade. The point was that warming can potentially occur far more rapidly than our wishful thinking would like.
I highly recommend this. It belongs in libraries, and should ideally be watched more than once to make sure you've got everything.
Changes seemingly associated with global warming have been occurring at an increasingly rapid pace in recent years, as has the advancement of our scientific understanding, so there is a danger these documentaries could become out of date quickly. That has not happened with A Global Warning?, in part because it includes the dramatic melting of Arctic sea ice in 2007, a key tipping point. What has happened since has mainly been more of the same, and faster. The documentary mentions the record number of tornadoes in the U.S. several years ago, and yet this past year eclipsed that record and saw many other weather extremes. It sure looks like a global warning.
One reason you should watch this is because it talks about the importance of methane as a greenhouse gas 26 times more potent than CO2. It shows where the methane is being released, including off the coast of California, as well as Alaska. It could have done a better job of explaining the importance of methane and the clathrate gun hypothesis, such as the risk of a vicious cycle or increasing temperatures and methane hydrates release, or that methane breaks down into CO2, continuing to cause damage in its afterlife. But it clearly shows the methane bubbles reaching the ocean surface, contrary to what some optimists believe.
This documentary is an excellent starting point, and an excellent review for those who have already been following the subject. It largely avoids being sensationalistic, letting the facts and experts speak for themselves. So on the one hand, it can be a bit dry and a tad boring, so you must keep your attention focused, or you will miss things. On the other hand, once the facts sink in, the inescapable conclusions are plenty sensationalistic.
Are we in deep trouble? It certainly seems so, though the documentary avoids such editorializing. Is there anything we can do? This it does not address, beyond one expert saying we still have some time to act, which may be optimistic. How much warming -- 2 degrees F, 2 degrees C, 5 degrees, 9 degrees -- is enough to wreak eventual havoc? This is not spelled out, either, perhaps wisely, because this estimate seems to be changing with further analysis.
How much time we have again is not spelled out. But one of the most shocking facts was that the earth warmed rapidly in a matter of decades 11,500 years ago, due to natural causes, bringing us out of an ice age. On the Greenland Ice Sheet, scientists calculate the temperature rose 18 degrees F. in just a decade. The point was that warming can potentially occur far more rapidly than our wishful thinking would like.
I highly recommend this. It belongs in libraries, and should ideally be watched more than once to make sure you've got everything.
