[ScottSolomon]

Extreme dependence on initial conditions and other nonlinear effects. Or, in other words, chaos. This means that tiny changes in the model's input lead to large and complex changes in the predicted output.

Sounds like you've been readin Bjorn Lomborg.

Sensitive dependence upon initial conditions explains why you cannot predict over which street a particular cloud will pass one day in advance. This is because we do not have a measurement grid with a resolution high enough to sample a sufficient level of data to provide an accurate model that far in advance. But highly chaotic weather patterns tend to smear out the number of bifurcations of possible weather trends over time.

We can predict certain trends and be reasonably sure those trends are accurate. In the case of global warming, the scientific community noticed a trend, then they sought to find a reason for the trend. Over time they came to the conclusion that the levels of CO2 - which we have a very accurate record of over the past 10,000 years - have been rising rapidly in the past century. We also know that the average temperatures across the world have been rising for the past century.

When climatologists run models, they don;t just run one or 2 they run 50 or 100. They take the most common results and the construct a probability matrix based upon the models.

The vast majority of the scientific community is in agreement about global warming. It is not just a fluke idea postulated by doom and gloom nuts.

We don't know the initial conditions. I am a regular reader of _Science News_. Every few months, researchers discover a new significant source or sink for CO2 and other greenhouse gasses. Each time one of these is discovered, it renders all previously climatological predictions based on modeling _invalid

Hogwash. Try reading a science publication that is a little less of a journalistic endeavor and more dedicated to hard sciences. Moreover, try reading Science News. I have noticed quite a few articles within it that acknowledge that global warming is real and anthropogenic.

In fact, the most common source for the myth that there is no scientific consensus is a book written by a guy called Bjorn Lomborg called "The Skeptical Environmentalist". The book was debunked for using selective notation, erroneous conclusions, and generally bad science. The guy basically used what information he had that could support his claim but ignored anything that was not in support of his hypothesis. The guy's book was heavily slanted toward scientific narrative instead of scientific research, and the journalists snapped the guy up as proof of a controversy.

There is not a controversy. There is a strong concensus.

I note that we're at the top of a ~110 year solar cycle

I know of an 11 year solar cycle, but I never heard of the 110 year solar cycle. Please enlighten me.

The only time I remember anything associating sun spot activity with 110 years was a study taking all the historica measurements of sunspots ( 110 years worth ) and charting their level of change. In that study, the highest reading occurred during the 1960s - which did not have higher average temperatures than the 70s, 80s, or 90s.

apparently the Earth's orbit is entering a period historically associated with warming

Right out of Lomborg's book. This is a gem The Milankovitch cycles take place over the course of tens of thousands of years. They are marked by glaciation and inter-glacial periods. We are currently in the Holocene - the most recent period of inter-glaciation. We are actually moving toward the cool end of the Milankovitch cycle - we will have an ice age in a few thousand years.

Within the Holocene there have been many periods of warmth and cooling, but the transitions have always been rather slow and periodic. Our current level of climate change has been very rapid ( on a geologic scale ) and it coincides with the industrial revolution.

extreme austerity measures like those demanded of the US by Kyoto are foolish

Kyoto is not extreme in any sense. It would require us to reconsider our priorities, but it would not be an overwhelming cross to bear. It has been mischaracterized by the Bush administration because it challenges the automitive and petroleum industries' short- term profit margins.

then there's the possibility that global warming might actually be beneficial

It will be to some areas - it will be horrible to other areas. The poroblem is, the burgeoning human population requires more foot and water every year. We currenlty produce a surplus of food and potable water. If our climate changes dramatically, it could have a huge effect on all ecosystems - greatly decreasing our ability to feed ourselves. This could lead to massive starvation, famine, disease, etc.

He who fails to plan, plans to fail. I would rather change what we can to ease the climate change as much as possible so that our descendants are not forced into a situation that may end up with the extinction of our species.