only two-legged carnivores could thrive?
There must have been a reasonable population of largish herbivores for the carnivores to eat.
Dinoboffins may have discovered why prehistoric giant lizards avoided the tropics for 30 million years, and thus solved a great fossil mystery. Research from the University of Southampton and its international partners sheds light on why the biggest dinos from the Triassic period took more than 30 million years to populate the …
"Throughout this period, levels of CO2 were four to six times higher than the levels we observe today, but the findings do indicate that if we continue our present course of human-caused climate change, similar conditions could develop and suppress equatorial ecosystems."
So, Earth can support 4-6 times higher levels of CO2 in the atmosphere and the temperatures will still not reach Venerian levels? Basically, after we burn all coal, oil and natural gas, Earth's atmosphere will be like in the Paleozoic/Mesozoic era?
Really a far cry from the alarm that climate scientists are raising.
Extra thumbs up to that one. I wonder if these people even read what they write.
"The conditions would have been something similar to the arid western United States today"
Last I checked, the Western States aren't experiencing out of control heat waves, causing 600 degree C fires... Excellent scientific conclusions there...
Check again.
https://en.wikipedia.org/wiki/List_of_California_wildfires
https://en.wikipedia.org/wiki/2014_Washington_state_wildfires
https://en.wikipedia.org/wiki/List_of_Arizona_wildfires
https://en.wikipedia.org/wiki/List_of_Colorado_wildfires
and it goes on for Oregon, Montana, Utah Nevada, Wyoming in fact if you do any simple research (use google) you'll find that, in fact, they're all very susceptible to summer wildfires.
I'm not sure you've understood the correlation between atmospheric temperature and ignition of vegetation, either. It's usually lightning that causes the ignition. The hotter the atmosphere the drier the vegetation and the greater chance of lightning.
Let's not scream climate change quite so quickly.
The Western states have been experiencing wet/dought/fire cycles for a very long time. One reason that recent fires have been so out of control is due to human-caused fire suppresion. This leads to an unnatural vegetation build-up - leading to bigger/badder fires. Realizing the mistakes of the past, the forest services frequently conduct controlled burns to mitigate this. Norther Mexico has pretty much the same climate and does not experience fires of the same sort is because they tend to let them burn until they run out of fuel.
Firstly, yes, I read "but the findings do indicate that if we continue our present course..." and wondered what the fuck it was talking about. The findings indicate that, based on the historical configuration of the Earth 60 million years ago, there has been observed and verified an effect on the ecosystem of highly elevated CO2 compared to today's Earth, of limiting the ecosystem based on energy from plants.
Why try to tack on a modern Climate Change conclusion?
Secondly, however, I would nitpick your conclusion that "Earth can support 4-6 times higher levels of CO2 in the atmosphere". It's about *rate* of change as well. Ecosystems need time to adapt and change. Go too fast and you get desert, flood or ice sheet. That's three ways to ruin your weekend.
"Basically, after we burn all coal, oil and natural gas, Earth's atmosphere will be like in the Paleozoic/Mesozoic era?"
Quoting the article: "... similar conditions could develop and suppress equatorial ecosystems."
Which makes perfect sense as current fauna & flora are adapted to the current conditions and their survival would be at stake. And the same can be said about the crops and cattle humans need to survive.
"So, Earth can support 4-6 times higher levels of CO2 in the atmosphere and the temperatures will still not reach Venerian levels?"
Most of the ecosystems we depend on for our survival would be totally screwed long before Earth temperatures reach Venerian levels. And everything from crops, cattle and fisheries to fresh water and energy generation would be seriously affected also.
Sure. A mass extinction. Something that anti-humanity movements have been advocating for a long time, assuming it would mean humans would be among the ones to go.
I saw data showing that carbon dioxide concentration went up from 300 ppm to 400 ppm since Industrial Revolution. That's about 140 more billion tonnes of carbon in the atmosphere, but we burned a lot more coal than that, not to even mention oil or gas, so the ecosystem is already compensating for the change (or possibly gaining, since such impressive compensation implies explosive growth?).
At the same time, summer temperatures didn't suddenly go from 300 K to 400 K, so it's obvious that even if the greenhouse effect exists, it's difficult to measure its magnitude, and it's possibly exagerrated.
Surely enough, scientists 25 years ago predicted that if we don't reduce our carbon dioxide emissions, the glaciers will be all melted by 2005, and average temperatures would reach 70 °C by 2015. By 2050, Earth would have the same atmosphere as Venus. It scared the shit out of me as a kid.
No only have we not reduced emissions (if I realized that then, I'd be scared senseless), but the emissions are constantly increasing (I'd probably develop paranoia and depression if I knew about it), and the glaciers are still there.
I'm sure I'm not the only one that heard those predictions. How do climate change alarmists expect people to listen to them if their lower-range predictions are not fulfilled, never mind the scary stuff?
as if there wasn't such an effect Earth's natural temperature, at this distance from SOl, would me markedly lower. I presume you meant to talk about change in the amount of greenhouse effect, and whether and to what extent any such change is caused by human activities?
My personal feeling on the climate change thing is that pumping large amounts of extra energy into our climatic system will only serve to help create more extreme weather events, as well as potentially raise the global temperature to some degree. Bearing in mind that there's now something like twice as many people on this planet as there was when I was born, that's a lot of extra energy - and it's sheer common sense to try to produce and use anything, including energy, as efficiently as possible. I think some folk underestimate the extent to which our food supply could be borked if even moderate climate change happens too quickly, or if an increase in extreme weather events makes the food supply too unreliable. Is humanity likely to go the way of the dinosaurs any time soon? No. But that doesn't mean that we couldn't loose a sizable percentage of our population to starvation and fighting over resources. Simple prudence dictates we should try not to wake that particular dragon.
On the topic of the article though - good work, those boffins!
@Esme: Oh, I'm not questioning the greenhouse effect at all. I'm questioning the contribution to greenhouse effect from carbon dioxide. Climate boffins are suggesting that if we keep pumping CO2 into the atmosphere, the temperature increase will stop supporting life on Earth and that we need to take action now.
Supposing that CO2 concentration will increase by 100 ppm over the next 50 years and that has terrible implications, it would mean that carbon dioxide is an extremely potent greenhouse gas.
However, the opposite would be true as well -- dropping CO2 concentration by the same 100 ppm would also have terrible effects. Yet we went from 300 to 400 ppm in a course of less than a century and almost nothing happened*.
What would happen at 0 concentration of CO2 in the atmosphere (other than plants dying, that is, which would actually happen at much more than 0)? If the potency of CO2 were so great, at zero concentration Earth would completely freeze over. It wouldn't? Then it means there are vastly more potent greenhouse gases and messing with CO2 is simply something that scientists know is perfectly safe since we can't screw it up.
*) Yes, I'm aware of climate inertia. At the same time, I see graphs showing a steady increase in temperature starting in mid-19th century and correlated with CO2 concentration, implying causation and very low climate inertia. You can't have it both ways. There either is inertia in which case we're doomed anyway, since the effects of current concentration are unavoidable and lowering CO2 concentration does sod all, or there's no inertia and our efforts then make sense in theory, but in practice, it's impossible to show any great impact from carbon dioxide.
This.
If we can get enough water to the plants we can graze animals and retain agriculture. Without the water supply you lose the plants and the rest is uncomfortable. I'd still prefer a more aspirational future for our species and the natural ecosystems but I agree, humans (in reduced numbers, obv) as a species could survive.
Maybe if there would have been carbon credits and exchange to trade them, then the dinosaur flatulence and dung creating CO2 and CH4 would not have led to the extinction by dinosaur made climate change. Then there is the possibility of man while carrying fire back to the cave dropped the stick and set the forest on fire leading to a world wide conflagration and thus man made climate change. Makes as much sense as today's theories.
pardon me, what makes 600 C fires be extraordinary? If anything, that would be colder than current extremes. Wikipedia "Wildfire" talks of 800 C.
Even if you could calculate a fire temperature from coal samples, a wildfire among sparse vegetation would be far from uniform, and, all in all, its measurement a rather silly exercise. But maybe there *is* something interesting in that... Anyone knows?