Matt----Do i have the title of the most negative now Actually, you are simply being realistic as is everyone who has commented on this topic. I've read through every comment and it is clear there is a consensus that the effect of AGW will be negative. Where optimism can be found in some comments, it relates to the ability of humans to adjust and accommodate the impact of AGW.
This is where I am most pessimistic in the near term and it has to do with the very nature of the most powerful way that human civilization has ever organized itself. Our current economic system has delivered amazing wealth and prosperity across the planet. While there are examples of seriously negative impacts, few nations have failed to benefit. Lengthening life spans are the single best statistic pointing to the universality of the benefits that capitalism has delivered. A vast infrastructure, representing the accumulated wealth of human civilization, spans the globe. This accumulated capital continues to generating incomes and wealth, delivering goods and services needed to support ourselves.
First, let's dispel the myth that leaders of our economic system are global warming deniers. While their public posturing may suggest this is the case, nothing could be further from the truth. Price Waterhouse Cooper, one of the most respected business research organizations in the world, has released a number of heavily researched advisories to industry. They are telling industry to adjust their capital investments to accommodate the certain dramatic impacts of AGW. Since a typical long term capital investment by business has a 20 to 40 year horizon, failure to do this could destroy a business. The insurance industry has released similar advisories regarding the increasing risks associated with AGW. Taken in isolation, this new focus on the very real impacts of AGW can only be interpreted favorably. They are finally getting it.
It is also pointing to the single biggest risk facing human civilization. Capitalism, despite its ability to deliver dramatically improving lives, is remarkably fragile and can be damaged by relatively minor perturbations. Five years ago, a financial crisis, driven by exotic investment instruments threatened the system. This drove huge flows of capital throughout the system as people sought safe havens. Many nations (Greece, Spain, Italy to name a few) are still suffering as a result while those countries that represented relatively safe havens (U.S. and Germany) recovered more rapidly. Keep in mind that this perturbation was purely financial. Nothing has physically changed in Greece or Spain that would cause their economies to virtually collapse. Last I checked, Spains unemployment rate was over 30%.
So why does the system resist the accepted truth of AGW? It is not because they doubt its veracity. It is because the existing capital infrastructure is dependent on the underlying rationale that caused its creation.
One example:
Archer Daniels Midland, over the past 10 years, has invested billions of dollars expanding a High Fructose Corn Syrup facility in Clinton, Iowa. It has had a major impact on the fortunes of what had been a depressed agricultural community. The facility stretches for three miles along the western banks of the Mississippi. If you ever drive by it, it is impressive. Heck, just use google maps, also impressive. The success of this investment is absolutely dependent on the industrial agriculture that surrounds it; monoculture, irrigation, high use of pesticides and petroleum based fertilizers. Regardless of how you feel about the viability of industrial agriculture, ADM and Clinton, Iowa will fight for policy that ensures its continued profitability. (Hint: If you ever find yourself in a tavern in Clinton, Iowa don't argue with other patrons about how HFCS is unhealthy.)
A second example: China has a huge advantage over the U.S. with regards to the percentage of their telecommunications infrastructure that is wireless. This is not because they are leaders in wireless technology but because they had so little land based telecommunications infrastructure in place. The U.S. telecommunications industry has a land based wire infrastructure that is valued in the hundreds of billions on their books. They simply cannot afford to write this off.
Third example: Houston, Texas owes its very existence to the huge capital investments in the petroleum industry. People may argue that there are other enormous economic strengths in Houston but make no mistake. Take away this industry or even shrink it significantly and Houston becomes Detroit.
The very underlying logic of capitalism is the preservation and exploitation of capital. Even in the face of real hardship, the system will work to preserve capital versus replace capital. This is due to the fact that a decision to replace capital destroys the value of existing investment. Any company that would choose to do this would be punished by the financial markets as capital flows move quickly away from such a foolish organization. Such a company would find that the cost of borrowing money in the form of interest rates would make it prohibitively expensive to make such a decision.
AGW will, in fact, destroy the value of existing investment globally as has been pointed out by all of the comments on this post. The impact on the worldwide financial system and the economic activity that it supports will be amazing (and not in a good way).