4 ms·

http://data.giss.nasa.gov/gistemp/graphs_v3/ http://data.giss.nasa.gov/gistemp/graphs_v3/

crusso 14y ago
Yeah, they show that temperatures have plateaued for the last 15 years despite models that the IPCC was 90% certain said that temperatures would continue to increase. http://suyts.files.wordpress.com/2013/03/image_thumb404.png?w=638&h=433 http://suyts.files.wordpress.com/2013/03/image_thumb404.png?... We know so little about how the earth will react to higher CO2 levels. It seems that we don't at all factor in solar and other cyclical factors that may just show that we're in a typical warming period. As a developer who has worked with physical world models before, if a model doesn't predict the future better than random guessing then it is worse than useless. In RF modeling, if we showed a customer software that predicted signal strength the way that the IPCC predicts temperature gains - we'd be laughed out the door.
- kaybe 14y ago
  More CO2 --> warmer is understood pretty well. What is not understood where else the gas can go and what feedback mechanisms there are. A climate model is very complex, and it is build on basic premises, which can all be tested separately (like the CO2 part). Some points remain unclear: For example, a great part of the CO2 that has already been emitted has apparently gone into the ocean (which will lead to acidification, another problem). The ocean has a turn-over time of about 1000 years, so we can expect more uptake. On the other hand, a warmer ocean can dissolve less gas. ..it's a very long list of interleaved issues, and small changes of parameters (whose values are not known precisely) can change big things. Great care is taken in making these models. Scientists are usually not interested in politics very much. Even if a few had an agenda, they wouldn't manage to push a made-up idea. Btw, the solar influence is also factored in (see [1]). The next ice age would be due soon, but it won't happen due to the CO2 (a good thing, I reckon). Looking at the climate history of our planet is a scary thing since it is far from stable. It appears that there are periods where the whole globe was covered in ice, and periods where it was very much warmer than today. It's ok for life, but not for individual species such as us who have build their civilisation on one specific situation (precipitation patterns!). In the long run, we will have to manage/stabilize the climate anyway, so research is needed either way. disclaimer: I study and do research in this area. If I could show there was no problem, I'd be a hero; nobody of us wants this. My professors seem to have given up on the issue at this point. Can I answer some questions or is this a lost battle as it is so very often? [1]http://en.wikipedia.org/wiki/Milankovitch_cycles http://en.wikipedia.org/wiki/Milankovitch_cycles
- RyanMcGreal 14y ago
  > they show that temperatures have plateaued for the last 15 years No, they really don't. The variation over the past 15 years, like the variation over the previous 120 years, is entirely consistent with a steady upward trend. Cherry-picking start and end dates is bad data analysis, period.
ctdonath 14y ago
To put that in context: http://ctdonath.blogspot.com/2012/02/global-climate-change-in-context.html http://ctdonath.blogspot.com/2012/02/global-climate-change-i... We're at the end of a natural long-term cyclic temperature increase, tending to rise fast then drift down, repeating every 125,000 years or so. If AGW is significant, we may consider it beneficial to counteract trending toward the next ice age.

Yeah, they show that temperatures have plateaued for the last 15 years despite models that the IPCC was 90% certain said that temperatures would continue to increase. http://suyts.files.wordpress.com/2013/03/image_thumb404.png?w=638&h=433 http://suyts.files.wordpress.com/2013/03/image_thumb404.png?... We know so little about how the earth will react to higher CO2 levels. It seems that we don't at all factor in solar and other cyclical factors that may just show that we're in a typical warming period. As a developer who has worked with physical world models before, if a model doesn't predict the future better than random guessing then it is worse than useless. In RF modeling, if we showed a customer software that predicted signal strength the way that the IPCC predicts temperature gains - we'd be laughed out the door.

kaybe 14y ago
More CO2 --> warmer is understood pretty well. What is not understood where else the gas can go and what feedback mechanisms there are. A climate model is very complex, and it is build on basic premises, which can all be tested separately (like the CO2 part). Some points remain unclear: For example, a great part of the CO2 that has already been emitted has apparently gone into the ocean (which will lead to acidification, another problem). The ocean has a turn-over time of about 1000 years, so we can expect more uptake. On the other hand, a warmer ocean can dissolve less gas. ..it's a very long list of interleaved issues, and small changes of parameters (whose values are not known precisely) can change big things. Great care is taken in making these models. Scientists are usually not interested in politics very much. Even if a few had an agenda, they wouldn't manage to push a made-up idea. Btw, the solar influence is also factored in (see [1]). The next ice age would be due soon, but it won't happen due to the CO2 (a good thing, I reckon). Looking at the climate history of our planet is a scary thing since it is far from stable. It appears that there are periods where the whole globe was covered in ice, and periods where it was very much warmer than today. It's ok for life, but not for individual species such as us who have build their civilisation on one specific situation (precipitation patterns!). In the long run, we will have to manage/stabilize the climate anyway, so research is needed either way. disclaimer: I study and do research in this area. If I could show there was no problem, I'd be a hero; nobody of us wants this. My professors seem to have given up on the issue at this point. Can I answer some questions or is this a lost battle as it is so very often? [1]http://en.wikipedia.org/wiki/Milankovitch_cycles http://en.wikipedia.org/wiki/Milankovitch_cycles
RyanMcGreal 14y ago
> they show that temperatures have plateaued for the last 15 years No, they really don't. The variation over the past 15 years, like the variation over the previous 120 years, is entirely consistent with a steady upward trend. Cherry-picking start and end dates is bad data analysis, period.

ctdonath 14y ago

To put that in context: http://ctdonath.blogspot.com/2012/02/global-climate-change-in-context.html http://ctdonath.blogspot.com/2012/02/global-climate-change-i... We're at the end of a natural long-term cyclic temperature increase, tending to rise fast then drift down, repeating every 125,000 years or so. If AGW is significant, we may consider it beneficial to counteract trending toward the next ice age.