With no water left on the surface, carbon dioxide built up in the atmosphere, leading to a so -
called runaway greenhouse effect that created present conditions.
About 1980ish, some old ideas like the
greenhouse effect were brought out of mothballs and re-examined with new tools and techniques; simultaneously several researchers and theoreticians released their notes, published, or otherwise got together and there was a surprising consilience and not a small amount of mixing with old school hippy ecologism on some of the topics that became the roots of Climate Change science (before it was
called Global Warming); innovations in mathematics were also applied to climate thought; supercomputers (though «disappointing» on weather forecasting) allowed demonstration of plausibility of
runaway climate
effects, comparison of scales of
effects, and the possibility of climate models combined with a good understanding of the limits of predictive power of weather models.