I am an advocate of manmade global climate change, and have been for a long time now. I was first convinced of the scientific validity of this in the mid-1980s. Every day since then has reaffirmed my scientific belief.
At the same time, I have stood fast against alarmist predictions. I have a hard time seeing the validity in them and feel they work against the effort to convince the public and politicians that we need to take action now.
I read today an article on scientificamerican.com that I think perfectly illustrates the point. This article was adapted from the book, "The Fate of the Species: Why the Human Race May Cause Its Own Extinction and How We Can Stop It," by Fred Guterl. Fred Guterl is not some light weight. He is the executive editor of Scientific American and has been doing science reporting for over 25 years. However, despite his credentials, Mr. Guterl is wrong in this article and I will show you why I say so. I have not read the entire book, so I will not comment on it.
The article focuses on nine 'tipping points,' as defined by climate scientist Tim Lenton at the University of East Anglia. Dr. Lenton identifies tipping points as a combination of factors that could lead to a sudden change in dynamic factors. In the case of the climate, these tipping points, he claims, could result in a change in the climate occurring in a matter of a few years or even a period of a few months. I do not dispute that each of the tipping points is a cause of concern. What I dispute is the idea that these might result in a catastrophic change in the climate over a short period of time.
Let me briefly summarize these tipping points:
1. Failure of the Indian Ocean monsoons. This is caused by the combination of pollution in the air that causes the monsoons to weaken and global warming which causes the monsoons to get stronger. The result is a kind of balancing act that could rapidly change the monsoons.
2. Failure of West Africa monsoons. The same as the Indian Ocean monsoons, except applied to the monsoons of West Africa.
3. Loss of Arctic sea ice. He postulates that as the summer ice sheet continues to get smaller and thinner it could eventually result in a year-round ice-free Arctic Ocean. This would result in continuous warming and a change in the ocean currents.
4. Collapse of the Greenland ice sheet. The ice sheet could collapse much more quickly that predicted (by a factor of 3 times faster), resulting is dramatic sea level rises worldwide.
5. Altering of the North Atlantic ocean currents. The change in fresh water in the North Atlantic Ocean due to the melting of the Arctic ice sheets and the Greenland glaciers will cause the dynamics of the North Atlantic currents to alter, greatly affecting the climate of Europe.
6. Collapse of the West Antarctic ice sheet. See the collapse of the Greenland ice sheet above, only much bigger.
7. Collapse of Amazon rain forests. Droughts get longer and more severe in the Amazon, leading to a change in the climate.
8. Collapse of Canadian boreal forests. Same thing, but with the Canadian forests.
9. Altering of the El Nino - La Nina Southern Oscillation. The Southern Oscillation drives much of the world's weather. Global warming will result in changes to this oscillation and cause changes to the world climate.
So, there are the nine tipping points he mentioned. Like I said before, I don't have any particular problem with this list, it is the time frame that I have the biggest concern with. To begin with, he defined a tipping point as something that occurred over a few years or even a few months. Some of these things, he states, will take hundreds of years to occur. That hardly fits the definition of a 'tipping point' that was put forth. Specifically, he estimates the melting of the ice sheets on Greenland and Antarctica will take about 300 years. In both cases, this is dramatically less than the more than 1000 years that is predicted for both. Still, 300 years is quite a bit of time. In comparison, the United States is only 236 years old this year.
Looking at numbers 1 and 2, the two about the monsoons. We are already seeing changes in the monsoons and this is an issue of great alarm. Well over 1 billion people depend on these monsoons for their livelihood and their food supplies. However, while we are certainly concerned with the idea of these monsoons changing, the scientific evidence does not support the idea that they may change dramatically, or even cease, anytime in the next few years. Could it happen? Possibly. And, we need to be concerned and work to prevent it. But, it is not something we need to worry about happening within the next few years.
Number 3 deals with the loss of the Arctic ice sheet. This is, once again, something of great concern. As the ice sheet melts the dark ocean will absorb much more sunlight than the bright ice that reflected much of it. However, the North Pole is in darkness six months of the year and the entire Arctic Ocean experiences lengthy, and cold, winters. It is not believable that the Arctic Ocean will be ice free throughout the winter in the foreseeable future.
I already mentioned numbers 4 and 6, concerning the Greenland and Antarctic ice sheets. Even if he is right, 300 years does not qualify as a tipping point. But, the change in the North Atlantic Ocean currents certainly does. This is one that he may be right about. In fact, one of the seldom discussed problems with the melting of the Arctic ice sheet is the fact that old ice is composed of fresh water. Ice slowly squeezes the salt out and so becomes more and more fresh as it ages. As this old ice is melting in the Arctic Ocean it is creating a large bubble of fresher water sitting on top of the ocean. There is concern that this bubble might be forced into the North Atlantic and we really aren't sure what would happen if it does. Adding billions of tons of fresh water from the melting of the Greenland ice sheet will only make matters worse. And, what is all of that extra fresh water going to do to the currents around Antarctica?
Changes in the Amazon rain forest are already being observed. As the forest is chopped back, it no longer has the critical mass to affect the climate the way it use to. Already, we see that droughts are more frequent, more severe and last longer in the Amazon region. These droughts are causing trees to die, which will only make the situation more severe. There is no speculation on this. It is already happening. But, will it suddenly collapse in a matter of years? There isn't anything to make me believe this is true. The Amazon is an area under great stress that we need to be actively working to save. But, I do not believe it will suddenly collapse in a matter of a few years.
All of this also applies to the Canadian boreal forests.
Number nine may or may not be valid. We are really learning a lot about the Southern Oscillation, but there is much we don't understand. Could it suddenly change or disappear? Really, I don't think we know enough at this time to say. But, neither does Dr. Lenton.
So, is there anything I see in this list that I am concerned with? Yes, every thing he listed is something I am concerned with. Do I believe these things will suddenly 'tip over'? No, I really don't think the time frame is that fast.
And, as I have stated before, none of this helps us. The public does not believe in a "climate Armageddon." Claims like this tend to turn them off and make them think all scientists are alarmists. At the same time, I don't ever want to be mistaken for someone that says we shouldn't be concerned about these issues. We should. And, we need to start working on them right away. I just don't believe that yelling 'wolf' is the best way to get people motivated.
Sooner or later, they won't listen to you anymore.