I think that the changes are excellent for the most part, but I am adding my voice to the call for not allowing anonymous publishing. It can certainly lead to mischief, and since a person can choose a screen name that is untraceable, I see little need to allow for the option.

If someone has a such a deep, dark secret that they don't want it known to the general public there are better ways of handling it than publishing a letter to the editor that will be read by thousands of persons.

I rarely have time to post letters these days due to a very busy schedule, but I nonetheless want to thank Glenn for his seemingly tireless efforts to keep us informed and for writing what has to be one of the best political blogs. His research on topics is in depth; his perspectives are always well articulated and thoughtful, and he keeps the tone far from the hysteria range. There is a hunger for what you do Glenn. Witness the huge number of posts in response to your work, well above even most of the insipid gossip pieces that "grace" Salon. Keep proving that intelligent discourse is possible and valued.

I know it's not intended as comedy, but the statement that Iraqis demanding that we leave is a sign of the progress that over 3000 of our troops have died for is so ridiculous on the face of it, that I don't know how the propagandists for the Bush administration can utter their talking points with a straight face. The absurdity of the situation is almost beyond belief. How much of a true believer does one have to be to passively accept such nonsense?

Just so everyone knows where the following comments are coming from, let me explain my background. I'm a professional biologist who teaches and does research in evolutionary biology and with a background in both ecology and evolution. I have many colleagues (some of whom are also good friends) who work on global warming issues. One in particular was one of the authors on the previous IPCC report, although not on the most recent one released in the last month.

As a scientist, over the last 12 years or so, I've watched as the evidence for anthropogenically driven global warming has accumulated. I remember well conversations with colleagues in the mid-90s when the evidence was tending strongly toward confirming that global warming was underway and that human activities were a significant driver of the change. At that time, most of my colleagues felt there was some solid evidence but would not rule out the possibility that they could be wrong. Models were still being developed and refined; the computational tools needed for simulations were good but much more limited than what can be done today; and certain types of data still needed to be filled in.

As the years passed, the evidence kept getting stronger, so that by the year 2000 or so, almost no one I knew doubted that warming was taking place or that human activity was at least partially responsible. At the turn of the century, the big questions for most scientists in the field were, "What proportion of the warming is due to human activity?," and "What is the rate at which the warming is occurring?" The evidence has only grown stronger since then.

Sure, there is a small handful of skeptics even to this day (just as there is a small number of researchers that still think that HIV is not the causative agent for AIDS), but they are a very small minority, some of which are suspect given their ties with industry. (Would you believe scientific results from the Tobacco Institute?) Could the scientific community nonetheless be wrong about global warming? Sure. But the probability of that has gotten fairly small.

Personally, I tend to look at the issue and how to respond in a cost/benefit way and because of that prefer a risk-averse approach to the problem.

Assume global warming is taking place and that the concerns voiced by the scientific community are for the most part correct. Taking strong steps to reduce greenhouse gas emissions would literally prevent major social and political upheavals associated with sea levels rising, tropical diseases extending their ranges into temperate areas, species going extinct as their habitats are lost, food supplies being disrupted as rainfall patterns change, etc.

Consider the alternative, global warming is not taking place/is not anthropogenically driven. If we put in place the laws, technology, etc. we think will avert global warming when it is not necessary, the worst case scenario is that once we figure out it isn't really happening, we can remove the constraints on fossil fuel burning, etc. and go about our business. Standards of living, may or may not be negatively affected by our pointless efforts to curb greenhouse gases. (To take one small personal example, I bicycle to work, in part to lower fossil fuel consumption, but I don't see that it reduces my standard of living.) Some efforts to curb CO2 emissions might be standard-of-living neutral or even beneficial, e.g., reducing our dependence on foreign oil.

In any case, since the risk of doing nothing is potentially so catastrophic and the evidence for warming is quite strong, it makes much more sense to me to do what we can now even if we later decide we erred to much on the side of caution.