200 million years ago CO2 was 5x higher, yet it was not much warmer why?.?

Question

Can anyone explain this?

Answer 1

http://earthobservatory.nasa.gov/Newsroo...

says

"an abrupt and dramatic rise in atmospheric levels of carbon dioxide triggered the massive die-off 251 million years ago"

Answer 2

There is very little evidence to show that CO2 and rising temperatures are even related. Or that greenhouse effect actually happens.  If you look at the geologic history of the earth you actually find that the temperature almost always rises before the level of CO2 and some times as much as 100-1000 years.  However there is a direct relation to the amount of solar acitvity such as sun spots and the rising temperature.  Some astromomers say that they believe we are in a 8000 year high in solar acitvity which would explain the rising temperatures.  besides in the 20's everybody was scared about global warming in the 30's an ice age. same thing in the 60's and 70's. In a few years everybody will be afraid of another ice age and everybody will some how forget that just a few years before we were in a global warming

Answer 3

There were more plants & less buildings with aircons, plants thrive on CO2, dinosaurs being reptiles are cold blooded & need the heat to keep warm. Mordern man were not there to complain about the heat... lol :D

Answer 4

The Sun.

You see, the sun has been slowly brightening over time. To get a good idea of the change in luminosity over the lifetime of the sun, you use the standard solar evolution model:

I⊙(t)=(I⊙(t⊙))/(1+(2/5)(1-t/t⊙))

Where I⊙(t) is the luminosity of the sun at time t, and t⊙ is the age of the sun (~4.6 billion years).

Basic information about the sun can be found here:

http://en.wikipedia.org/wiki/Sun#Life_cy...

On that wiki page, you learn learn about the "Faint Young Sun Paradox", which is the basis of your question. The idea is this: even as the sun has continually brightened, the Earth's temperature has remained relatively constant--that is, in the range of habitability. So far, the only possible explanation for this is GHGs. The inverse relationship between Solar luminosity and GHG concentrations over the lifetime of the Earth is a tricky one, but there is much reading on the subject for a curious mind.

Ken wrote

"So, for example, if the climate sensitivity to CO2 is 1.5 C (a conservative estimate)....this ignores any feedback mechanisms..."

Actually, a climate sensitivity of 1.5 C would include feedbacks, as the climate sensitivity to CO2 alone is only .6 to 1 degree C.

Answer 5

http://math.ucr.edu/home/baez/temperatur...

There is a chart here which shows inferred temperatures the last 4 billion years.  200 million years ago was the end of the Triassic.  It was much more stable warmer dryer world through most of the Mesozoic but it was relatively colder 200 million years ago though still probably warmer than today.  Notice has scraggly the line gets in modern times.  I don't think that CO2 concentrations has been shown to drive temperature.  Perhaps they might increase temperature stability and lower the gradient from different latitudes.

Note: Dinosaurs were likely warm blooded endotherms IMO

Answer 6

There were more plants & less buildings with air conditioners ,

Plants use CO2 in the process of Photosysnthesis and reduce surrounding temparature equal to 10 Air Conditioners .

1 Tree absorb equal CO2 generated from 100 vehicles .

So as many Trees  are down that much CO2 adds to the environment .

4.5 Billon tons of CO2 is added every year .

Carbon dioxide is heavy than oxygen in weight so it would bring warme

Answer 7

You mean when the earth was a steam bath with cold blooded dinosaurs runing around.   Palms growing everywhere in cold weather sounds a little strange to me.  

Answer 8

err yes it was warmer!

http://www.globalwarmingart.com/wiki/Ima...

Answer 9

If you or anyone would think about this you would see temperature is a result of energy not CO2. It takes energy to get higher temps and even if the CO2 level is 5 times higher the energy is unchanged so the temp also is unchanged. The CO2 was even higher 300 million years ago.  

Answer 10

Water vapor is the main greenhouse gas, It masks out any smaller effect that CO2 might cause.  Scroll down a little ways on this page as there is a fair explanation

http://www.jamesphogan.com/mailarchive/i...

The CO2 argument would make a little sense if you neglect water vapor, but that is not fair to do on a planet that is 2/3 covered by water.

Answer 11

The greenhouse effect of CO2 isn't linear.  So, for example, if the climate sensitivity to CO2 is 1.5 C (a conservative estimate), then a doubling of CO2 would raise temps 1.5 C.  Another doubling (4x the original) would raise it another 1.5 C (total of 3.0 C).  Another doubling (8x the original) would raise it another 1.5 C (total of 4.5 C).  This ignore any feedback mechanisms (e.g. huge release of methane from thawed permafrost, etc.) which could dwarf the effect of CO2 alone.

And it's important to keep in mind that temperature reconstructions (i.e. estimating the temperature from long ago) are not considered precise measurements.  So anyone that says the temperature 200 million years ago was "only" 3.5 C warmer than now is greatly exaggerating what they actually know.

Answer 12

This article begins to explain it:

http://www.nature.com/nature/journal/v44...