If we continue with business as usual as 'skeptics' want, how much will the planet warm?

going by your fig.2, over 6 degrees. it will be A1F1 until at least 2050, and the forcing will be at the top of the ipcc range. then the arctic methane and ice feedbacks really kick in....

What this skeptic wants is to develop transportation solutions and energy conservation that will ease the energy crisis. What I don't want is taxes and energy-cost increases that fund carbon trading "schemes" (read scams) and discredited climatologists. The increases in carbon dioxide can be enterpreted as nothing less than a moderating force in the environment, with major benefits to plant growth on the planet. The tree-ring data that provided the foundation for the IPCC models correlate with carbon dioxide. Trees grow better when carbon dioxide approaches 1,000 ppm. It doesn't necessarily correlate to a higher temperature. Their hypothesis is flawed, evident in current temperature decline.

Trick question. Nice try Dana. The real Skeptical answer is, "We don't know." And anybody with a brain bigger than their ego knows this is true. We know that doubling CO2 concentration should lead to about a 1 C increase in temperature.

We don't know how all the other forcings work. This winter in the UK is evidence of that. The Argo buoys finding the oceans are cooling slightly is evidence of that. When a guy with a laptop can beat the Met predicting the weather (see link), it's clear that conventional wisdom (groupthink) among climatologists is flat wrong. Look Dana, your guys missed the last two winters and the summer before. And we are supposed to trust their predictions for 90 years in the future.

When somebody with a laptop and public information can beat a whole group of scientists and their supercomputers, something is wrong. I have NO confidence in their end of the century predictions.

Now give me four TD's from you and your aliases and explain why the Met can't figure out if the upcoming winter will be hotter or cooler than average.

The ultimate scenario, business as usual, full steam ahead, frack everybody, would likely lead to about a 10C or 18F increase in global average temperatures by the time things are done. Your other respondents have pointed out things like tar sands and oil shale, so figured I'd throw in hydro-fracking, which devastates underground areas. Coupled with the surface ecological damage from our current mining practices as we get every drop of hydrocarbons we can wring out of the earth, every puff of natural gas, we will have set ourselves up for a range of possibilities from total social and technological change to effective collapse of the current civilization. I'd estimate that I might be off 2-3C for the low side, and 5-7 or 8C for the high side, giving a range of 7-18C for eventual warming, roughly 12-25F, and I strongly suspect even the low end would prove slowly catastrophic, as weather disaster after weather disaster unfolds, battering an ever-weakening civilization running on ever-diminishing sources of power.

For this prediction, I will be called an alarmist of the worst sort. But what was asked was best guess at a worst-case scenario. There's no point in soft-pedaling a slow Armageddon.

Unfortunately, these people think that 1.8°C is a minor change. On a global scale, that is most definitely not a "minor" thing. I'm guessing that the temperature will rise 2.5-3 degrees.

Whether stopping the use of fossil fuels will do anything is debatable, apparently.

I'd only add that running out of oil won't save us from our folly because when oil looks permanently settled above $100 per barrel, people will just start liquefying coal, like WWII Germany and apartheid era South Africa. In fact, that switch will make things worse, since coal releases more CO2 for the same amount of energy.

Interesting that you quote the IPCC, an organization of the UN, I would point out that the UN also predicted that Iraq under Saddam Hussein would never attack Kuwait, that prediction was made in the summer of 1989, and of course the first Gulf War was in full bloom by 1990, in defense of Kuwait, and SA. They also predicted that the threats made by the Taliban leader, Bin Ladin, was not of substance and should be ignored. Their troops in Afghanistan actually escorted him to the border with Pakistan soon after the 9/11 attack. The events of 9-11 demonstrated they were incorrect. They also continue to state that Iran is only interested in "peaceful" nuclear applications, and of course N. Korea can be reasoned with if they would just agree to sit down and discuss the issues. The IPCC is of course just a organization for the UN to further their socialistic ideals of transferring wealth from the "developed" countries to the "undeveloped countries". Their accepted paradigm of anthropogenic global climate change is just the current vehicle to accomplish that end. Now, that being true, we obviously should still continue to develop alternative energy types from a national security point of view. It is in the national interest to do this. Nuclear generation of electrical power is the most obvious choice, as it is clean, safe, and proven. Additional hydroelectric dams is another choice which should be exploited. Wind energy and solar are basically in their infancy, and they will only survive if subsidized heavily by the governments, either through direct funding, tax incentives, or taxes on existing geochemical energy production. ( Taxes on energy use, like the Cap and trade taxes proposed in the US are a bad idea.) These technologies are likely dead end as they are not dependable, predictable, or cost effective when compared to other methods. The IPCC is European dominated, socialistic in nature, and contrary to their statements, are never policy neutral and always policy prescriptive. Therefore virtually all of their proposed scenarios which you have introduced as a basis for you question are suspect. The history of the UN, and its offshoots is just not conducive to trust in their predictions.

average 2 to 6C is what I hear and this could be conservative and it is likely more in polar regions. Make it 3-12F so ordinary americans really understand.

the argument will of course be it's not CO2, but natural, like the MWP.

By 2100, it's likely that oil will be more expensive than alternatives. We'll run out of the easy stuff and start digging tar pits and sands and in 20,000 feet of ocean for the last drops.

First, you are making the wrong assumption. Most of the Developed Nations are taking steps to move to renewable energy and energy efficiency. It is only people like you who want to allow China and India do business as usual while punishing the Nations making progress.

Second, you are using computer models that are biased towards CO2 as being the only factor in climate change.

Pride will keep them from ever admitting to being wrong.