SI is so useful [and cyberspace in general]. It's really absolutely phenomenal. I ask a question which would be really hard to answer and bingo, you find some of the answer right where I hadn't bothered clicking around [due to huge tsunamis of information and ADHD]. Thanks.
Timeline of temperatures and land mass distribution. Getting there.
The future is interesting. In Mq's theory, since the land will be bunched around the equator the ice sheets won't be able to cover it. scotese.com That means lots of heating through absorption of sun radiation into the ice free oceans, and a hot and steamy future with sea level higher.
On the other hand, it could mean lots of reflection due to equatorial deserts instead of equatorial oceans. Which would mean lots of cooling.
But the bunching into Gondwanaland, Pangea, Laurasia seems odd. I wonder how the geophysicists know Gondwanaland was together all at the same time. Maybe it was, but shifting upwelling magma plumes seem likely to float the land masses around a bit more randomly than that. But maybe not.
Gondwanaland being near the south pole resulted in vast ice sheets, low sea levels, cold climate and low CO2 as the oceans sucked all the CO2 out of the air and didn't put O2 back in, because fish wanted it and they end up on the ocean floor, subducted, producing oil, gas, volcanoes [some recycling there] and limestone in sedimentary basins.
It's all very interesting, and we can be sure that as land masses keep moving and plant cover expands and shrinks, and gamma rays increase and reduce and Earth's orbit wobbles around and we rescue more fossil carbon from its eons-long grave and vent it into the atmosphere, things will get warmer or cooler, deeper or shallower.
The one thing that seems sure is that it's premature to get too worried about CO2 content of air.
Mqurice |
