Atmospheric CO[SUB]2[/SUB] levels have increased even more than the IPCC predicted in 2001. If their predictions were correct there should have been an even bigger increase in atmospheric temperatures than they predicted, but over the 11 years since their report was published there has been no increase in those temperatures.
Why? What is missing?
The core of every climate model the IPCC uses is the idea that for every unit of increase of temperature caused by CO[SUB]2[/SUB] there will be a total increase of 3 units caused by water vapor. This is where almost all of the warming they predict comes from. If it were only forcing from CO[SUB]2[/SUB] then the atmosphere would only warm by about 1[SUP]o[/SUP]C over the next 100 years. It is the water vapor feedback that they insist will cause the catastrophic warming they predict.
Astonishingly, there is an ongoing debate about whether or not their assumption about that feedback is correct. Even with the latest data from the Aqua satellite it's not entirely clear. Some scientists point to subsets of that data as proof of strong feedback, others point to the same collections of data as evidence that there's not a strong feedback from water vapor.
The difference in interpretations appears to depend on how data on clouds and precipitation figure in. One interpretation is that the interaction between temperature, water vapor, and clouds only goes one way, that is, elevated temperatures lead to increased water vapor. Another interpretation has it going both ways, that is, elevation of temperature increases water vapor which increases clouds and precipitation which, later in time, results in lower temperatures. In other words, one side argues that when the whole cycle is considered feedback from water vapor is a lot lower than one would find from studies of the effect of water vapor forcing with clear skys.
The computer models used to make the predictions published by the IPCC can't be used to model this because they can't model cloud formation and precipitation. Those are included in the models only as static parameters.
But, whatever the cause, none of the computer models used by the IPCC have been proven to be accurate using data collected prospectively, i.e., data collected after the prediction was published. It would be foolish to base public policy on such inaccurate models.
Why? What is missing?
The core of every climate model the IPCC uses is the idea that for every unit of increase of temperature caused by CO[SUB]2[/SUB] there will be a total increase of 3 units caused by water vapor. This is where almost all of the warming they predict comes from. If it were only forcing from CO[SUB]2[/SUB] then the atmosphere would only warm by about 1[SUP]o[/SUP]C over the next 100 years. It is the water vapor feedback that they insist will cause the catastrophic warming they predict.
Astonishingly, there is an ongoing debate about whether or not their assumption about that feedback is correct. Even with the latest data from the Aqua satellite it's not entirely clear. Some scientists point to subsets of that data as proof of strong feedback, others point to the same collections of data as evidence that there's not a strong feedback from water vapor.
The difference in interpretations appears to depend on how data on clouds and precipitation figure in. One interpretation is that the interaction between temperature, water vapor, and clouds only goes one way, that is, elevated temperatures lead to increased water vapor. Another interpretation has it going both ways, that is, elevation of temperature increases water vapor which increases clouds and precipitation which, later in time, results in lower temperatures. In other words, one side argues that when the whole cycle is considered feedback from water vapor is a lot lower than one would find from studies of the effect of water vapor forcing with clear skys.
The computer models used to make the predictions published by the IPCC can't be used to model this because they can't model cloud formation and precipitation. Those are included in the models only as static parameters.
But, whatever the cause, none of the computer models used by the IPCC have been proven to be accurate using data collected prospectively, i.e., data collected after the prediction was published. It would be foolish to base public policy on such inaccurate models.
