Do environment talks such as in copenhagen help prevent global warming?

i think no such talk will bear fruitful results until all the countries want to make it work..... at times it is the americans that put the roadblocks... at times it is the chinese government.... nobody wants to slow down their pace of growth and development... they want to shift all the onus to their developing or underdeveloped counterparts.... i dont think all this talks will bear any fruit until the leaders stop thinking just about their country with a short term view... instead we should try and save the planet and life.... because no growth can take place if the very existence of mankind is in danger....