It is the amplifying effects that we can only guess at. When there is higher carbon dioxide, then water vapor becomes and amplifying affect. With higher heat, we get more evaporation, so there is more vapor in the air, so we gain more heat. (And this is why we get more rain and more snow and since there is more heat energy, we get higher intensity storms.)
The open water in the Arctic has a much lower albedo (heat/light reflectivity) than ice and snow, so once more ice melts, then the water gets even warmer. Check the ice data:http://nsidc.org/arcticseaicenews/
Dying trees in the boreal forests in particular are another amplification effect. And melting tundra (so-called perma
frost) is releasing a huge amount of methane, which is 20X as strong a greenhouse gas as carbon dioxide. And with warming periods in the past, when the climate gets warmer, this *increases* the carbon dioxide (this lags by about 800 years), which is another feedback / amplification effect.
The ocean is getting more acidic as it absorbs carbon dioxide, which may well reach a "saturation" point when this absorption slows down. This lower pH / more acidic ocean is having a huge affect on life in the ocean, and this is having a large effect on the climate.
We have been in an unusually low level of sunspot activity -- as we move into the increasing part of this ~22 year cycle and as sunspot activity increases the sun puts out more heat. (Even though sunspots themselves are cooler, the overall output increases when there are more sunspots.) So, we have had record heat *while* the sun has been *unusually* cool. What will happen in the next 10-11 years?
If you read (all) of Naomi Klein's article -- you will see that she writes about all of the effects on our lives. We already have rising ocean levels, We already have longer, hotter, and more widespread droughts. We are already having more intense rainfall and these are occurring in many places around the world. Food crops are failing more often, and higher heat is reducing yields. Fish are not only suffering from intense over fishing, but the plankton is down 40% from the late 1950's -- they are the base of the food chain.
Acidification is affecting plankton and shellfish and corral. As it happens, the colder parts of the ocean in the best fishing areas, there is lower pH because the adjacent coasts are primarily granite. Places where the coasts are primarily limestone are not as acidic, but they are often in warmer areas, where fishing isn't as good to begin with.
All the effects of global climate change are already here and they will only increase. The pattern of the data as it is gathered has continued to be worse than the worst projections.
What we all face -- all life on this planet -- goes way beyond politics. It will affect all people, in all countries, no matter if you are poor or rich. Naomi Klein writes about this, too.
We are all threatened, and we ignore this at our peril.
The good news is -- we need to make the transition from oil and coal and gas *anyway*. We have reached peak oil. The tar sands are proof of peak oil. (And the significant amount of additional energy and water that we would use to get it, would amplify the warming even more.)
A GROWTH economy is impossible to sustain. Even with a constant population -- and we are past the point of sustainable use of virtually everything. Let that sink in, please.http://www.youtube.com/watch?v=ybRz91eimTghttp://www.youtube.com/watch?v=b3_mYowxlEghttp://www.youtube.com/watch?v=2p6U-ZvR5Ykhttp://www.youtube.com/watch?v=JyO0WS79Xechttp://www.youtube.com/watch?v=F5EcK-CdLNAhttp://www.youtube.com/watch?v=hJpUswRKwIw
So, even without global climate change, we would need to transition to a steady state economy
I realize that this is a huge challenge. I realize that this is a huge threat to people's ideas and philosophy and politics. But the science our best understanding of reality. And anything that doesn't include reality is only going to make the challenge greater.