Is Global Warming becoming unstoppable?

wayneL said:

1. Can the fall in rainfall be scientifically links to emissions?

2. Is there any evidence of long tern rainfall averages (over centuries)?

3. We all know climate can change due to natural and other anthropogenic factors (land use etc), but where is the evidence this is exclusively due to GHGs.

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An important issue for the future is the potential for significant sea level rise due global warming. Sea level rise consists of two parts: a steric contribution (volume increase due to an increase in average ocean temperature, which reduces average seawater density), and a mass contribution (volume increase due mainly to melting of land supported ice… glaciers, ice caps, and ice sheets). It has been projected by some (Vermeer & Rahmstorf, and others) that the mass contribution will accelerate rapidly in the next few decades as average surface temperature increases; these projections suggest a rapidly accelerating sea level rise, starting very soon. While the IPCC AR4 projections of sea level rise through 2100 are modest, some more recent projections suggest increases of well over 1 meter by 2100. My guest posts at the Blackboard in July 2011 addressed this issue, and the results of my model suggest future sea level increases in reasonable agreement with the AR4 projections, for a wide range of assumed rates for surface temperature increase.

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Conclusions, Observations, Cautions

The satellite sea level data shows no evidence of acceleration in the rate of ice melt over the past 18 years, and the observed reduction in the rate of sea level rise since ~2003 is consistent with a much reduced rate of ocean heat accumulation. The relatively short period of the satellite record means that one should be cautious about drawing too many conclusions from the data; the measured trend of the last 18 years could be influenced significantly by unaccounted factors. The good news is that continued satellite measurements of sea level and ARGO measurements of ocean heat content will allow more confident estimates of any change in the long term trend over the next decade or two. I personally expect the sea level trend to not accelerate nearly as much as some have suggested, and I expect that projections of extreme rise in sea level by 2100 will be largely refuted within 15- 20 years.

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Knobby22 said:

1. No, it is just one of a number of smoking guns.
2. No.
3. It can't be exclusively to GHGs, but there is a reasonable probability that it is partly caused by GHGs. As stated earlier in the thread, GHGs are still a weak factor in the weather and it is difficult to pull the threads of weather effects apart. We need more time and more studies. I saw a study about there being another "el nino" type oscillation between the Indian Ocean and the WA coast that effects weather over most of Australia. This has been going the wrong way over the last 30 years but is going our way at present. (at least at the time of the article 2 years ago), given time we will understand the weather and thus the climate better.

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Knobby22 said:

1. No, it is just one of a number of smoking guns.
2. No.
3. It can't be exclusively to GHGs, but there is a reasonable probability that it is partly caused by GHGs. As stated earlier in the thread, GHGs are still a weak factor in the weather and it is difficult to pull the threads of weather effects apart. We need more time and more studies. I saw a study about there being another "el nino" type oscillation between the Indian Ocean and the WA coast that effects weather over most of Australia. This has been going the wrong way over the last 30 years but is going our way at present. (at least at the time of the article 2 years ago), given time we will understand the weather and thus the climate better.

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wayneL said:

Yes.

But can you provide a rainfall history chart over the same period?

Dam inflows are affected by others things in addition to rain

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IFocus said:

Maybe the inflows are being affected or blocked by all the dead and and nearly dead trees that are now becoming part of the permanent landscape.

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qldfrog said:

true and we need to be ready with mitigation strategy: more storm, higher average temperature and so evaporations: need more dams
Look at the situation here in Brisbane where dams are design for both mitigation AND drinking water storage
DUHHH as Homer Simpson would say; it is not compatible: a mitigation dam should be empty by the start of the rainy season...
Time to use some brain in infrastructure design

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Arctic sea ice loss 'unprecedented', study finds
November 24, 2011 - 7:30AM

The loss of sea ice in the Arctic at the end of the 20th Century is “unprecedented” in the past 1,450 years in its duration and magnitude, an indication of human-influenced climate change, a study said.

So-called greenhouse gases may be contributing to the warming, and trends from the last several decades suggest there may soon be an ice-free Arctic in the summer, according to a study published today in the journal Nature.

The ice, which melts every summer before cold weather makes it expand again, shrank this year to its second-smallest size since 1979, covering 4.33 million square kilometers (1.67 million square miles), according to the US National Snow and Ice Data Center. Although previous sea ice declines have occurred at a similar pace, they don’t match the extent of the melt, the study authors said.

....Arctic sea ice influences the global climate, since 80 percent of the sunlight that strikes it is reflected back to space. When the ice melts in the summer, it exposes the ocean surface, which absorbs about 90 percent of the light, heating the water, according to the National Snow and Ice Data Center. That influences climate patterns.

“You increase the radiation that’s absorbed by the oceans, that’s one of the strongest climate feedback mechanisms,” Kinnard said. “The more sea ice you lose, the more energy you get in the ocean, which warms the atmosphere.”

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basilio said:

On a similar note to my previous post here are some before and after pictures of glacier melts taken over a 2 year period.

http://www.smh.com.au/environment/glacier/before-after

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bandicoot76 said:

last i checked wood floated... but of course i'm no scientist so i could be wrong

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Three themes are emerging from the newly released emails: (1) prominent scientists central to the global warming debate are taking measures to conceal rather than disseminate underlying data and discussions; (2) these scientists view global warming as a political “cause” rather than a balanced scientific inquiry and (3) many of these scientists frankly admit to each other that much of the science is weak and dependent on deliberate manipulation of facts and data.

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Sea level rise is not level

Of the many things about global warming misunderstood by the public at large, the irregular or lumpy distribution of sea level rise must surely be near the top of the list. When sea level rise is mentioned, this typically refers to the global average or mean, but this obscures the fact that not all areas of the ocean are rising. In a few regions sea level is actually falling, while at others it is rising at a rate much larger than the global average. So even though the total volume of seawater from melting land ice, and thermal expansion from ocean warming are increasing, this isn't being evenly spread around the oceans. See figure 2 below.

It just so happens that the western Pacific and Tuvalu in particular, are one such region where there is a large rise in sea level, much greater than the global average. See figure 3.

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basilio said:

Came across a discussion on sea levels rise as global warming takes hold. It's funny because most people would "expect" that water would find its own level around the world and therefore sea levels would rise equally.

Not true.

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So_Cynical said:

...The Deniers will not be well represented.

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sails said:

That seems wrong. Why shouldn't both sides be represented?

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