[WylieE]

Oh yeah,
 I meant to add this as another link for more articles and links on climate change:
http://www.aaas.org/news/press_room/climate_change/

[another_someone]

OK, have skimmed over much of the report.

Three big omissions

1)it admits that it does not take into account the impact of volcanism because of their episodic nature (but not because the impact does not exist).  Given the very short timespan covering most of this report (mostly since 1960, since that is when reasonable global figures can be ascertained), and that is a very short period over which to measure changes in volcanism, it seems a great deal is left uncertain here.
2)It does not explain why Antarctica is not showing signs of global warming.  If Antarctica cannot be relied upon as a measure of current global weather, then how reliable are the ice cores taken from Antarctica as a measure of historic data?
3)There is no change in diurnal temperature variation, although I would have expected that an increase in global warming caused by the greenhouse effect would have had a significant impact in reducing diurnal temperature differences.

It admits to a great deal of uncertainty in the impact of aerosols in cloud formation.

The fact that it suggests an increase in drought, and a reduction in rainfall, is in direct contradiction of what is traditionally associated with global warming, or with what one would expect with variation in rainfall caused by changes in temperature.  On the other hand, if the changes in temperature are a consequence, rather than a cause of, changes in cloud cover, then this is the pattern one would expect.

One problem with arguing that the effect is totally down to reduced cloud cover is that, just as one would expect the greenhouse effect to reduce diurnal temperature differences, reduced cloud cover should increase them, and at present the indications are that there is no change.

The uncertainty factor in their judgement of the effects of aerosols seems to be just about equal to their expected total effect of the impact of CO₂.

One other factor that is mentioned, and is considered noticeable but small, is the level of soot reducing the albedo of snow.  The effect of this is probably small on a global scale, but would have a marked effect locally, and in particular it could explain why ice is retreating in the northern hemisphere (where there may be significant soot), but not in Antarctica, where one would not expect much soot.  This seems to pretty much match their observations.

Most of the figures indicate that the changes were more significant changes in the temperatures in the last quarter of the 20^th century, but this was also the time of increasing efforts at reducing anthropogenic particulate and  aerosol pollution, and these aerosols could well have contributed to cloud formation.

Understandably, there is no real analysis of data before 1960, since the datasets before that time are sparse, but it does mean we are dealing with a very short period of time with regard to global climate.  The only comment that was made was that CO₂ levels in the ice cores (although it does not mention which ice core samples it is using) are the highest they have been for 650,000 years.  What is also interesting is that even the pre-industrial levels of CO₂ were already at the well above the lower end of what they consider to be the normal range (the lower end being 180ppm, and it was already at 280ppm before the industrial revolution commenced), thus indicating a long term rise in CO₂ that long precedes the industrial revolution.

Some interesting comments:

Paleoclimate information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1300 years. The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 metres of sea level rise.

In other words, although it has not been significantly warmer for an extended period of time in 125,000 years, they have left open the possibility that it was as warm for extended periods of time, of even warmer for short periods of time (whatever an 'extended period' might mean).  They have also not indicated whether the weather we have now is in any way unusual prior to 700AD.

Ofcourse, the biggest problem is that this is a summary for policy makers, and thus targeted at politicians rather than scientists.  But then, the very raison d'etre of the IPCC is the it is an Inter- governmental organisation, rather than a primarily scientific organisation.

[paul.fr]

The Age of Stupid

 [ Invalid Attachment ]

A climate scientist's view of 2055
Pete Postlethwaite in the film

As the film The Age of Stupid hits cinema screens across the country, audiences may ask themselves if the projected climate changes for 2055 are realistic, and what action they can take now to reduce and prepare for the future consequences.

Our climate impacts expert Dr Richard Betts takes a scientific look at what our world may be like in 2055.

He explains: "To help predict what the future climate might be like the Intergovernmental Panel on Climate Change (IPCC) has developed different scenarios, ranging from reducing emissions in the short-, medium- and long-term, to continuing emissions growth around the world. Under the IPCC scenario of ongoing emissions, global temperatures are projected to increase by about 2 °C by mid-century. Temperature rises are likely to be greater over land and at the poles.

"Sea-level rise is projected to add around 20 cm, on average, to coastlines around the world, so storms are much more likely to cause flooding. Extreme weather is also likely to become more frequent. The intensity of hurricanes may increase.

"The changes to our climate depicted by the Age of Stupid are certainly not science fiction. They are at the extreme end of the projections, but still plausible, and very real changes are already taking place in our environment. Those detailed below are just some of the changes we're most likely to see by the middle of this century.

"While some changes in climate cannot be reversed, if we act now we can decrease the risk of big changes in the second half of this century. Further changes depend on what we do now to curb emissions of greenhouse gases. However, even with drastic cuts in emissions beginning in the next ten years, our research suggest there will only be around a 50% chance of keeping global temperature rises below 2 °C."
Different changes in different places

    * UK — winters set to become wetter increasing the risk of flooding. Summers may become drier, with the possibility of more droughts. Temperatures will rise — leading to milder winters and warmer summers. Heatwaves, such as the 2003 heatwave, could occur every other year, on average.
    * Europe — climate change may not be all bad, at first, with the ability to grow crops further north, increasing productivity. However, crop yields are expected to decline at higher temperatures. In the Alps the smallest glaciers may have disappeared and larger ones shrunk by 30–70%.
    * Africa — East Africa may see an increase in rainfall, but the continent is likely to have difficulties adapting to climate change due to poverty, poor health and hunger. Water resources will become increasingly scarce as the risk of drought increases. More of the population will be under water stress and there will be more risk of migration and conflict. Find out more about the effects on the developing world.
    * India — river-flow from glacier meltwater, on which many people's lives and livelihoods depend, will become more erratic as the glaciers will have already shrunk. Crop productivity may increase in parts of East and South-East Asia, but decline in other areas.
    * South America — the Amazon rainforest will be mainly affected by the continuation of logging activity. Climate change may also cause the forest to die back, especially if it has already been weakened by deforestation. By 2055, we could be committed to further loss of the forest ecosystem later in the century if it dries out in warmer temperatures.
    * North America — reduced water supplies will become a major concern. Ozone levels in cities, a growing respiratory irritant, are set to rise, causing an increase in ozone-related deaths by 5%.
    * Australia — hot, dry weather, giving a high risk of wildfire, is expected to occur more often and be more severe. Additional heat-related deaths for people aged over 65 are also very likely with an extra 3,000 to 5,000 excess deaths expected every year.

[frethack]

The point is that it really does not matter who is paying you, but most science is problem driven (whether it is a cure for cancer, or global warming), and scientists (like engineers) are being paid to solve a problem, and if they come back and say there is no problem, then it will be difficult to justify continuing to pay them.

I used to believe just exactly that, but it really is a terrible misnomer.  With a few exceptions (as with anything), 99.99% of researchers are not beholden to some money machine that dictates their direction and results.  My professors are very well respected paleoclimatologists that are doing cutting edge research, and I talk to them enough to know that they are very passionate about their work and do not alter results because it fits an agenda.

So.. My question is what is the current research (if you know) and is there a consensus. Could you direct me to any articles regarding this.

There is a consensus that man is having *some* effect on the climate system.  As far as the degree of that effect compared to natural variability, there is not consensus.  Popular science articles are very often surprisingly hyperbolic when describing the scientific literature, so I dont know if I could really recommend any.  Are you by chance a college student?  If so, I can give you some journal articles that you can look up through your library.