If you heat the planet then you also heat the ocean; you get more evaporation; water vapour is a good greenhouse gas, you get a positive feedback which increases the temperature even more. Bit, if we have more water vapour in the atmosphere, we also form more clouds and it turns out that clouds are the dominant uncertainty in global circulation models.
We can see there is no correlation with the CO2 in the atmosphere and the temperature of the Earth.
The claim that there isn't any other explanation and therefore the warming must be primarily human is wrong. There is another explanation: Solar Activity.
Also on NCTCS blog:
James Taylor reported for Forbes on the EIKE Climate Change Conference HERE and Prof Dr Henrik Svensmark's address "The Climate is a result of changes in the clouds"
can be found here.