In the 1990's scientists started to question the greenhouse effect theory, because of major uncertainties in the data sets and model outcomes.
They protested the basis of the theory, which was data of global annual mean temperatures.
This made him one of the world's leading global warming experts.
In 1988 it was finally acknowledged that climate was warmer than any period since 1880.
It was also discovered that water vapor absorbed totally different types of radiation than carbon dioxide. He concluded that adding more carbon dioxide to the atmosphere would intercept infrared radiation that is otherwise lost to space, warming the earth.
The argument that the oceans would absorb most carbon dioxide was still intact.
Environmental NGO's (Non-Governmental Organizations) started to advocate global environmental protection to prevent further global warming.
The press also gained an interest in global warming.
It was also believed that the oceans were such great carbon sinks that they would automatically cancel out our pollution.
Water vapor was seen as a much more influential greenhouse gas.