The first few posts of this thread were about hydrogen fuel and it then became a debate about climate change and it seems there is a very broad range of opinions on this topic.
However, putting climate change aside, there are other very good reasons why hydrogen should be developed as a fuel and also why the world needs to be less reliant on fossil fuels.
The first reason is that reserves of fossil fuels are finite. Although there might be considerable debate about the exact extent of reserves they will run out within the next few centuries. It is a good idea to start looking for alternatives before supplies of fossil fuels begin to run out.
Another reason is that there are other problems associated with fossil fuels such as air pollution, acid rain, the risk of oil spills (e.g. Exxon Valdz disaster) and also global political and security problems related to securing oil supplies. (This last point does not just have to apply to the Middle East. Consider the situation in Venezuala, Nigeria, Aceh or East Timor also).
Finally, there are alternatives and they are becoming increasingly available. Wind power is growing at an exponential rate. Germany and Denmark both get 15% or more of their electricity from wind. There is the potential for massive savings in energy use through developing more efficient vehicles and transport systems and housing. It is cheaper to give solar panels to villages in developing countries than it is to construct large power stations and connect the villages to an electricity grid.
I was surprised when the Texas oilman in the White House made the announcement about spending a lot more money on hydrogen fuel research. However, I think it was a recognition of the fact that if the US didn’t devote enough research to this field the Japanese and Germans would get the jump on them and the US would get left behind.
[PS I am sorry if anything I have written in this thread is interpreted as being anti-American. Australia and Canada produce as much pollution on a per capita basis as the USA and they also deserve criticism. I guess because the US is so big and dominant in international politics that it automatically becomes a target for criticism.]