I'll try and provide some facts for both sides of the argument.
Posting from my phone, so it'll be rather brief.
Fundamentally, the people who doubt the more dire predictions have good reason to do so. The current and projected CO2 levels are, in fact, nothing special in the grand scheme of things. There's even some measure of doubt as to the exact scale of the problem and the potential causes of it; not only has CO2 been significantly higher in the fossil record, it has seen at least a few massive spontaneous drops, typically accompanied by mass extinctions.
Which does pull into question the whole correlation/causation issue with CO2...
For myself, I'm skeptical of everything, and anthropogenic global warming is no exception.
CO2 levels has been higher in fossil records, yes, but it has also been linked to a great catastrophe of that time. For example; the mass extinction of Dinosaurs where whole continents were burning. The eruption of Yellowstone, the eruption of Toba, etc. Most of these have also been linked to an Ice Age following slightly afterwards, though. Ther're not "normal" spikes per-se; they're usually caused by a drastic event.
Also, one must consider the fact that the Earth naturally goes through continuous heating and cooling cycles on its own. For example, around the turn of the last millennium, global temperatures were higher than they are now. In fact, there is evidence that shows there were types of plants growing in Britain in the 1100's, I believe, that cannot be grown there today because the climate is too cold.
I haven't read said evidence, and I'd like to read those articles if you can find them.
And about the correlation between CO2 levels and global temperatures, I can remember there being a chart posted in a previous thread on the subject some time ago that showed CO2 levels increasing AFTER temperatures rose. I'll have to do some digging to see if I can find it.
If you don't know the inner workings of how CO2 levels work, then one might claim this is proof that Global Warming is false. However, it is only natural that CO2 levels raise after the temperature increases if you know how water solutes CO2. Cold water can contain more CO2 than warm water. Thus, as the temperature raises, the water temperature rises along with it. As the water heats up, it releases more CO2 in to the atmosphere - causing the temperature to further raise.
This also has a natural break so it doesn't snowball out of effect - as the temperature raises, more water evaporates, which leads to more water in the atmosphere. This causes more rain, and allows rain to travel to places where it normally doesn't rain - mainly Africa. As rain now falls on places it normally doesn't, it allows plants to grow where they normally can't. The new plants help with lowering the overall CO2 levels in the atmosphere. This, stacked with the fact that rain takes CO2 from the atmosphere with it down to the ground, where it is absorbed by the mud. The new plants stacked with increased rain both work towards lowering the CO2 levels of the earth, once again cooling it.
In addition to this; more open water means more heat that's absorbed - which is somewhat countered by the addition of more clouds; which is the direct opposite of water in that it's the most reflective surface on earth (as it consists of snow).
Hence some people doubt over the correlation/causation question when it comes to CO2. The problem comes in when, as I said, you consider that for the majority of the history of the planet, CO2 levels were, in fact, much higher than they are today.
And we still had glaciers.
Now, local temperature variations could account for that. Or maybe not. Paleoclimatology is difficult, to be honest. Records like tree rings are notoriously inconsistent, ice cores are half-decent snapshot of local atmospheric conditions, but on the whole, a lot of it is... well... guesswork.
No. During the modern earth (as in, the last few million years since complex life forms started walking the earth) CO2 levels has not been overall much higher than it is today. It fluxuates with time. Only once has Earth been a snowball (meaning covered with ice from pole to pole), and never has all ice been gone.
Yes, Earth is naturally supposed to be in a warmer period right now. However, the DANGER is with the EXTRA CO2 that we humans produce. Fact of the matter is, the climate is EXTREMELY complex. We can't accurately predict how the normal warm period of Earth stacked with the extra CO2 that we humans produce will affect the earth in the future. We don't know if the Earth's normal safeguards will be enough to counter what we humans produce. Normally CO2 levels raise slowly over a long time. But right now it raises quicker than normal. The only other times it has spiked quick is after catastrophes such as huge volcanic eruptions. Will the glaciers smelt? If they do, the ocean levels
might raise by between 1 and 30 meters depending on the severity - which will cause great catastrophes in many parts of the world, where entire nations may end up on the bottom of oceans.
Tampering is such a strong word... Manipulating is more fair, to be honest.
The problem is that there are a few bit of global warming evidence that do not support their claims, in a broad sense. So they go out of their way to downplay the Medieval Warm Period, they figure out a way to explain the relatively stable temperatures through the 60's and 70's, and they massage the data as best they can to present a clear case for global warming.
It's bad science, frankly, but that's never stopped people in the past.
Part of the problem, of course, is that we're looking at an incredibly vast and complicated system, where we don't even understand all the variables, much less how they interact.
Take the economy, for example. (Please, ba dum tish.)
We can't really predict what that will do reliably, and it's much simpler than the climate.
In fact, when you think about it, economists and climatologists have an awful lot in common. Both can look at the data from the past, and discern patterns from it. Both can see that some correlative factors that they believe may have strong causative links with certain outcomes. And both of them like to imagine that they can understand and predict something that is vastly more complex than any human could manage.
Now, in the next few decades, we'll likely have computers that could manage it, to an extent. Assuming we can handle the programming, lol.
Quite honestly, you can't trust any source. The anti-global warming nuts are just as guilty as the pro-global warming nuts in manipulating data. It's not something solely isolated to one side.
To put things in perspective: The Eocene-Oligocene extinction event is one of the more recent in geologic history, occurring a little over 30 million years ago. While nobody is entirely sure what caused it, climate change, specifically in the form of rapid cooling, is the suspected culprit. Atmospheric CO2 levels appear to have plunged during the event, dropping from as much as 1500ppm down to less than half that.
It's not the most recent; the latest extinction happened a mere 30000-60000 years ago when mankind almost went extinct. We went from a booming population to a mere 10000 individuals - which can be seen by comparing genetic data. But yes; it's the last "major" extinction event.
Events like the E-O extinction are one of those things that make people question the causative links between CO2 levels and global warming. It raises the idea that the planet either has some means of rapidly reducing CO2 concentrations, or the CO2 levels are a result of global warming, rather than a cause of it.
It's both, actually. As I said earlier; oceans are what controls the climate. The most prominent evidence of this is El Niño and El Niña. During one, the temperature raises by a few degrees on average - sometimes for a few years - while the other reduces the temperature slightly. El Niña actually see an average temperature drop of 3-5 degrees from the average, while El Niño raises the temperature by 3-5 degrees.
Look at how different the world would be without the Gulf. Sweden, Norway and Finland would be like Siberia and mostly uninhabitable. It would be covered in an ice sheet, and the glacier would crawl much lower than it is today. During almost every major climate shift (and it is one of the reasons as to why the last extinction you talked about happened) is a combination between, say La Niña and a stream change.
There's also several other factors to take in to consideration that can cause a climate change; the earth's axis tilt, distance from the sun, sun activity, moon's distance from the earth, polar location, core spin, tectonics, geoactivity. All of these can, under the wrong/right circumstances, cause a climate change.
Look at is as funnel; depending on the water flow, it'll remain at at a equal level. Increase the water flow (as in, more conditions get added or increased) and water level will increase. With enough conditions (or each condition is stronger, such as more and more CO2 levels) and the water will flow over and cause a climate change. On the other hand, not enough conditions will also cause a climate change by emptying the funnel.
Look at Venus and Mars; they're both in the Goldilocks zone - that is the zone that's "just right" - however, neither of them can support life as we know it- on Venus, the funnel emptied and stay emptied; causing it to be way too hot. Mars on the other hand overflowed; causing it to be too cold. It's a shame too - Venus is the only other planet in the Goldilocks zone which has shown evidence of Tectonic activity. The only other body we know of is the moon Titan - which is way outside the Goldilocks zone.
It's quite sad that if you do a google search, the only sites you'll find are either strongly for or strongly against global warming. Sadly, the same goes for scientists. It's either doomsday prophecies or "It's all lies". If you have any questions I'll try to answer them neutrally, though.
Fact of the matter is, I personally believe global warming to be true. I do
not, however, believe it to be as serious as a lot of people make it seem to be. It is also, in no way, negligable. It's better imo to play it safe,
just in case it is of significance, as the people that will get hurt by it are our future generations and not us. It's easy to say "Well, who cares? Won't affect me". But consider this; Would you be happy if your previous generations fucked up your life and left you to clean up the mess? If it DOES matter, it's better to start preventing it now, instead of leaving it to future generations when it may be too late. There's only one life form in all of Earth's history that has managed to change the climate before, and on top of that cause an extinction of 99% of all life forms; and that's the Algae that started producing oxygene. Will humans be the next one?
That being said; mass extinctions aren't necessarily a bad thing. Throughout all of evolution, max extinction has ALWAYS been a good thing. It's like a mass wipe of failed creatures - allowing only the successful and strong ones to spread their genes. Each and every mass extinction has resulted in an evolutionary prime with even more creatures that are more successful and stronger than ever before. I don't see how that's a bad thing. I truly believe humans are strong enough as a species to survive a mass extinction, and emerge stronger than before.
It may be unethical and immoral to say, but there's too many of us on earth, and this damned pampering needs to stop
Edit: Raesvaelg; it's unfair to blame CO2 emissions on China. The REASON China's emission is so large is because of the Western world. We all have this "deal" that we need to lower our CO2 emission by X% before Y date. But instead of modernizing our factories, we move them to China - which actually leads to an overall higher emission rate because the factories aren't as modern. Yes - we lower our own emission, but we're directly responsible for an increase in China's emission. Technically, that's still our emission as the factory is ours. China's OWN emission isn't very high at all if you look at the emission/population for what China produce for themselves.
I can fully understand why China refuse to sign a paper to lower their emission rate by X% - and instead plan to increase their own emission - when you consider that they produce almost everything for the entire modernized world. Signing such deals means that they'd have to stop their own modernization and stop producing things for themselves, as there's no way in hell the Western world would allow them to close their productions in China. All in all, signing such a deal would be bad - not only for China, but for the whole world, as China's modernization means they can afford to upgrade and improve not only their fabrics (resulting in less emission from production and also more effective and faster production), but also their cars and every other facet of life, which would overall lower their CO2 emission in a foreseeable future.
