[Temperedoil]

Professor Aleklett may well be correct that we will never release enough carbon dioxide into the atmosphere through the burning of fossil fuels to lead to the changes that have been proposed as likely by various other scientists. However, we do not need to in order to impact the climate and Earth's ecology to a sufficient degree to potentially lead to such changes.

We do not need to push the climate all the way to complete melting of the Greenland or West Antarctic ice caps ourselves. We do not need to cause the increased storm activity or severity ourselves. We only need to push the system far enough for feedback loops to develop.

Earth has had many shifts in climate in the past, as you have noted yourself. These natural shifts have eventually led to opposing shifts as the planet's systems constantly push toward a balance. Although the Greenhouse Effect is itself essential in order for the abundance of life to exist as is presently the case on Earth, there is a limit to how pronounced that effect can be before a state of imbalance (one detrimental to life on Earth) enters the system.

Humanity is not responsible for the Greenhouse Effect itself, but the evidence suggests that the world is warming. When looking at the possible reasons for this, a growing number of scientists have come to determine that humanity's burning of fossil fuels (representing vast stores of carbon locked away for millions of years) are at least partially responsible for the increasing Greenhouse Effect.

Other possible explanations, such as solar activity, have been ruled out as not being enough on their own to lead to the observed changes (though some of them may still play their own roles, perhaps they would have helped bring balance to the system in the absence of the human impact, or they may have eventually led to the observed warming themselves following an additional natural shift).

From what I understand of Professor Aleklett's statements regarding fossil fuel burning and the greenhouse effect, it seems that his main argument is that we will not be reaching the levels of greenhouse gases through the burning of fossil fuels due to the impact of Peak Oil. Where the fossil fuels become too difficult and expensive to extract, and at declining rates, so that we stop burning the quantities required well before reaching the levels suggested by the IPCC. Although this makes a lot of sense in the Peak Oil context, it would at first glance appear to ignore the impact of feedback loops and tipping points. At what point do we start to see the release of gases trapped in the frozen soils of Siberia? At what point do we start to see the Arctic absorbing rather than reflecting heat and light from the sun? Would we have had reason to be concerned about such matters if we had never started burning fossil fuels?

[Starvid]

I agree with pretty much everything you say. Except these feedback loops. They are not well understood, at all.

If they do exist, why didn't they kick in during the medieval warm period? Why not during the warm times a few thousand years ago?

[Starvid]

By the way, this is the warmest winter in 280 years in Uppsala. It might be an even longer time since we had such a warm winter, because we don't have records for more than 280 years, and it has never been this warm.

Anyway, according to the meteorologists this has nothing to do with climate change and everything to do with the fact that the high pressure systems are at unusual places this winter. The warmth around here is due to the same reason that has deep frozen everything from the Berings strait to Riyadh.

The climate fluctuates on its own.