We're all going to die!
OK, a trite saying, which will always be true - the only question is when.
Dr. Hansen's point is what we are doing today could lead to an earth where human life is either gone or very very little left (my hopeful spin on it) in approximately 500 years.
I notice others have written about the book, but I think they did not bring out the key points. Also I offer a "my spin" on the book, along with some critiques.
One item I think should be Front and Center, BIG and BOLD- if we do not change the amount of CO2 contributed to the air in the next 20-40 years, the amount of warming will exceed our human ability to live on this planet.
Dr. Hansen does a reasonable job of walking through the science, politics, history and projections. One of his points is the positive feedback to the system the increased temperature will have. Once started, the increasing temperature is harder and harder to stop.
One fear is the increased sea level of ~100 feet. This is a nearer term problem.
I might point out here, melting ice consumes a lot of energy. If one heats a glass with ice cubes in it, it takes a while for the ice to melt – and during this time the water temperature is slowing rising, particularly if there is good mixing of the water, i.e. good thermal transfer of heat via convection. When the ice is finally melted, then the temperature of the water increases rapidly.
Part of the problem with our ability to politically deal with the issue will be the lag time. The time between the initiating events and the results. Once started, this process gets harder and harder to change.
So this is the scary part and why Dr. Hansen wrote the book. Part of the global warming is not simply things getting hot, but also the storms - wind, rain, hail, & snow will be increased. Storms would increase due to the increased water vapors in the air. Hurricanes become more powerful as they cross warm oceans. Just imagine what would happen if the ocean temperatures were "only" 10 to 20 C warmer.
Note that ~75 Million years ago, the situation is the sea level was ~100 feet higher, and the estimated global temperature was +14C higher. Easily 20F higher than today. Also during this time it appears there was not an ice cap.
Dr. Hansen did a good job explaining the science, the observations, the uncertainties, and history behind the global warming. Interestingly he started his career by looking at Venus. A planet with mostly CO2 atmosphere and surface temperatures of 450C. I could follow the logic and the explanations- but it was spread out in the chapters intermingled with stories of politics and science. The forecasting part seemed reasonable. The one area we might be missing is the question of is there any possible negative feedbacks to the system? If, as Dr. Hansen states, most of the effects are positive feedbacks then we will see an acceleration of
heating.My complaints with the book are more the organization and story.
Reading the book reminded me of reading "Lord Jim" by Joseph Conrad in college. I could not understand why English teachers loved "Lord Jim". Lots of description of items which did not seem to relate to anything. The story really did not start until 2/3 of the way through the book. I eventually bought the Cliff notes to find out what the heck was going on- because I just could not finish reading the book. I think others may suffer this reading Dr. Hansen's book.
At time "Storm" seems to meander between science, politics, future forecasts, and personal stories.
My highly edited and summarized (with opinions) short version:
1)What might happen if we continue the way we are going
It is likely we will create and earth atmosphere where human life is not viable. Perhaps in some locations, but not like population has spread across the globe as today.
2)The science behind all of the predictions
CO2 increase correlates with the predicted temperature rise. The CO2 acts as an absorber of sun energy. Aerosols (must pollution) act as a reflector and diminish the energy retention, but at lesser extent than CO2. Methane also acts to retain the sun's energy. With frozen methane in the tundra and in the ocean it is likely this will act to accelerate the temperature increase. Ice and Snow reflect sun light, with less Ice and Snow more of the sunlight energy is absorbed, thus increasing the temperatures. Variation in the Sun's output is not large enough to reduce the heating increases due to the other effects.
In the past ice ages, the heating up of the earth has progressed at a rapid rate. The sea level has increased ~100M (300feet) in the past ~17,000 years ago to ~7,000 years ago. The sea level has been somewhat stable since ~7,000 years ago to until recently. To go from the last warm period to the coldest point in ice age took about 100,000 years. A very slow process compared to the warming up. [as a note we should be looking for Noah's Arc below the current sea level]
3)The politics - what has happened so far and why it is difficult
Simply put nothing has changed. We are still increasing CO2 output. Many of the political agreements have not yielded significant change. Getting people to recognize the issue and respond to the dangers are difficult. In most cases,we have only changed when the situation is very obvious. Like closing the barn door after the horse has left. In this case it may be hard to reverse directions, so the need to educate is very large.
4)What can we do
Hopefully we can educate the politicians and people to the dangers we face. Choosing a method to change behaviors (such as reducing CO2 emissions) will important.