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maykI am again amused, it seemed, first it was global warming, then it changed into climate change, now it must be Methane. I wonder what is next.
1 and 2. I agree that China is doing its bit ... but the population hasn't finished expanding yet - maybe 2040 or 2050, when it hits 1.6 billion (currently about 1.35 billion)1. I don't know why in 50 years china will need all that extra electricity. Remember, in 50 years time China's population will be less than the current population, unless their one child policy is repealed.
2. ... China is doing its bit for environment.
3. But no one talks about this ...
4. In fact India will be a bigger problem in a few decades.
Monday, 16 March, 1998, 21:19 GMT
China population prediction
The State Family Planning Commission in China says the country's population will hit a peak of one-point-six billion before beginning to decline in the middle of the 21st century. [say 2050?]
The current population stands at just under one-and-a-quarter billion. [ in 1998, or 1.35billion now].
Moreover, a traditional preference for male offspring, especially in the countryside, appears to have intensified as parents have fewer children over all. Selective-sex abortions are illegal but widespread. China today has the most sexually skewed adolescent and young adult populations in the world; boys outnumber girls at birth by a ratio of 118 to 100, according to China's 2000 census. The normal rate is 103 to 105 males for every 100 females.
"We're going to have a situation in which every young man has to worry about caring for two parents and four grandparents"
India population 'to be biggest'
By 2050 there will be 1.63bn Indians, the study shows
India is set to overtake China as the world's most populous nation by 2050, while some countries will shrink by nearly 40%, according to new research.
The Population Reference Bureau (PRB) says the next half century will see wild swings in population sizes.
It predicts that the number of people on Earth will reach 9.3bn by 2050, compared with 6.3bn today.
Britain's population is likely to overtake that of France, while the US will grow by nearly 50%, it says.
The Washington-based PRB says the general trend will be for Western developed nations to decline slightly in numbers - the US being the major exception - while developing states continue to expand rapidly.
PREDICTED POPULATIONS, 2050
1 India, 1,628m (2)
2 China, 1,437m (1)
3 United States, 420m (3)
4 Indonesia, 308m (4)
5 Nigeria, 307m (9)
Source: PRB (2004 position in brackets)
The organisation says that at present "nearly 99% of all population increase takes place in poor countries".
India is expected to grow from 1.08bn to 1.63bn people, overtaking China, which is forecast to reach 1.44bn from 1.3bn currently.
Climate myths: CO2 isn't the most important greenhouse gas
But the overall quantities of these other gases are tiny. Even allowing for the relative strength of the effects, CO2 is still responsible for two-thirds of the additional warming caused by all the greenhouse gases emitted as a result of human activity.
two thirds I guess -How much of the observed ~0.74C warming in 100 years does this represent?
If the rate last century was 1.7mm/y and the present rate is 2.5mm, surely the current rate is accelerating over the rate for last century!I was more interested in the fact that sea levels had risen further in the earlier part of the century
PS: Lately there has been no acceleration.
1993-2003 (3.1mm/y)
2003-2008 (2.5mm/y) - that's ~20% lower.
http://climatesci.org/2009/01/07/se...te-altimetry-and-argo-by-cazenave-et-al-2008/
If the rate last century was 1.7mm/y and the present rate is 2.5mm, surely the current rate is accelerating over the rate for last century!
More silly cherrypicking of figures to prove what, exactly?
Climate scientists prefer a 30 year time frame to determine trends as lesser periods succumb to other variables.Exactly what I said, that lately we have not seen an acceleration in the last 5 v's the 10 before 2003 . . nothing more, a simple observation.
Lately to me is not the last 100 years.
Climate scientists prefer a 30 year time frame to determine trends as lesser periods succumb to other variables.
Comparing a 5 year trend (average) to a 10 year trend is not particularly clever and, as I said, is tantamount to cherrypicking.
It's one thing to make a "simple observation".
It's another to make a valid one.
I have no problem with the odd millimeter. But you introduced a 20% change in rates:It`s still valid, not intended to be clever, and was initially a response to 2020's comment.
Lets not make a mountain out of a millimeter.
I was more interested in the fact that sea levels had risen further in the earlier part of the century
PS: Lately there has been no acceleration.
1993-2003 (3.1mm/y)
2003-2008 (2.5mm/y) - that's ~20% lower [my emphasis].
Nonlinear trends and multiyear cycles in sea level records
S. Jevrejeva, A. Grinsted, J. C. Moore, and S. Holgate
published 12 September 2006.
We analyze the Permanent Service for Mean Sea Level (PSMSL) database of sea level time series using a method based on Monte Carlo Singular Spectrum Analysis (MC-SSA). We remove 2–30 year quasi-periodic oscillations and determine the nonlinear long-term trends for 12 large ocean regions. Our global sea level trend estimate of 2.4 ± 1.0 mm/yr for the period from 1993 to 2000 is comparable with the 2.6 ± 0.7 mm/yr sea level rise calculated from TOPEX/Poseidon altimeter measurements. However, we show that over the last 100 years the rate of 2.5 ± 1.0 mm/yr occurred between 1920 and 1945, is likely to be as large as the 1990s, and resulted in a mean sea level rise of 48 mm.We evaluate errors in sea level using two independent approaches, the robust bi-weight mean and variance, and a novel ‘‘virtual station’’ approach that utilizes geographic locations of stations. Results suggest that a region cannot be adequately represented by a simple mean curve with standard error, assuming all stations are independent, as multiyear cycles within regions are very significant. Additionally, much of the between-region mismatch errors are due to multiyear cycles in the global sea level that limit the ability of simple means to capture sea level accurately. We demonstrate that variability in sea level records over periods 2–30 years has increased during the past 50 years in most ocean basins.
Sorry, that link seems to be ok today ...... Unless of course we're pretending it's monotonic (which is ridiculous)
Here's NewScientist on this :-
http://www.newscientist.com/article/dn11641
It goes on to say "as this demonstration neatly illustrates." - but the link ( as I mentioned) seems to have expired. It was better than this youtube, and included the effect of tilting...
Imagine this system as an analogy for climate. For the sake of argument, suppose the magnets correspond to different climatic regimes: the yellow magnet to an anomalously mild winter, the white magnet to an especially cold winter, the red and blue magnets to other winter states having more-or-less normal temperatures.
The second animation shows the same pendulum system, but with a wedge moved in underneath the base. The wedge represents an external perturbation to the system, here the perturbation associated with anthropogenic increases in carbon dioxide. With the wedge firmly in place - representing, let's say, late 21st century levels of carbon dioxide - let's see how the system evolves. The motion is still chaotic, so that late 21st century weather variations are still irregular and therefore impossible to predict in detail. However, one can clearly see that the probabilities of occurrence of the four winter regimes are no longer equal - the mild winter is now significantly more likely that the cold winter, even though the system does make occasional unpredictable excursions to the cold winter regime
These animations [courtesy of Rob Hine (ECMWF)] illustrate a number of climate issues which have caused conceptual difficulties from time to time:
1. Even though climate is chaotic, with weather states impossible to predict in detail more than a few days ahead, there is a predictable impact of anthropogenic forcing on the probability of occurrence of the naturally-occurring climatic regimes. This lies at the heart of the CLIVAR perspective on climate change - how anthropogenic forcing will affect the natural modes of climate variability.
2. In our chaotic climate, it is impossible (indeed meaningless) to try to attribute a specific (eg severe) weather event to anthropogenic global warming. Hence, it is a false dichotomy to suppose that some recently-occurring drought or flood is either on the one hand caused by global warming, or on the other hand is merely due to natural climate variability.
3. Rather, the correct way to address such an issue is to ask instead whether anthropogenic climate change will increase or decrease the probability of occurrence of the type of drought or flood which we (or journalists pursuing some weather story provoked by a recent drought or flood) are interested. Such probabilities can be obtained, for example, from the JSC/CLIVAR Working Group on Climate Modelling's multi-model ensemble, made for the IPCC fourth assessment report.
4. In a chaotic climate, one cannot expect the time-series of global temperature to increase monotonically under the impact of anthropogenic climate change. Hence, for example, global mean temperatures were especially warm in 1998 because of the occurrence of a substantial El-Niño event. By the bullet above, it is meaningless to attribute the 1998 El-Niño event to global warming. Only by looking over long enough periods of time can one see the trend in global mean temperature due to anthropogenic climate change, above the "noise" of climatic variability.
Rob,I have no problem with the odd millimeter. But you introduced a 20% change in rates:
And for any stats junkies:
Our global sea level trend estimate of 2.4 ± 1.0 mm/yr for the period from 1993 to 2000 is comparable with the 2.6 ± 0.7 mm/yr sea level rise calculated from TOPEX/Poseidon altimeter measurements. However, we show that over the last 100 years the rate of 2.5 ± 1.0 mm/yr occurred between 1920 and 1945, is likely to be as large as the 1990s, and resulted in a mean sea level rise of 48 mm.
Isn't this just saying variance, not increase or decrease?We demonstrate that variability in sea level records over periods 2–30 years has increased during the past 50 years in most ocean basins.
Sorry, that link seems to be ok today ...
http://www.clivar.org/science/magnets.php
I post jpegs - if you want the animations they are on that link.
But obviously the chance of ending up on the yellow magnet are higher with the tilt ( = anthropogenic effects)
The periods quoted by spooly are within a highly probable range of large variability.Rob,
Don't the stats that you produced say that the variance in 20-45 ish was the same as just recently?
And,
Isn't this just saying variance, not increase or decrease?
Maybe that is the point, but I thought it was about increases.
Perhaps variances are worse?
The periods quoted by spooly are within a highly probable range of large variability.
That variability may render any conclusions as meaningless.
Over and above that, the reliabilty of the data is subject to standard error.
Again, the standard error can account for entire diference in sea level rate changes quoted by spooly.
How much of the sea level change is due to man-made non-warming related factors? It wouldn't be zero and if this hasn't been included in the models then that ensures they aren't accurate.If the rate last century was 1.7mm/y and the present rate is 2.5mm, surely the current rate is accelerating over the rate for last century!
More silly cherrypicking of figures to prove what, exactly?
Penguins Of The Antarctic
Time: Sunday, January 11, 7.30pm
Channel: ABC1
Duration: 55 minutes
Documentary
The penguins of the Antarctic lead extraordinary lives, with their home the coldest, windiest and driest place on the planet. But how are they coping with the effects of climate change?
The Scottish Government has committed to an 80 per cent cut in emissions by 2050
The last emperor? Penguin numbers plunge
11 December 2007
By IAN JOHNSTON
ENVIRONMENT CORRESPONDENT
"TAKE it all in all, I do not believe anybody on Earth has a worse time than an emperor penguin," wrote Antarctic explorer Apsley Cherry-Garrard on returning from Robert Scott's ill-fated expedition to the South Pole.
Nearly a century later, life for the largest of all the penguins is dramatically worse and the very existence of this iconic species is now under threat, according to conservation group WWF.
Emperor penguins breed in the ferociously harsh Antarctic winter, surviving blizzards, eternal nights and temperatures of - 49C.
But some colonies have halved in size in the last 50 years with climate change bringing warmer temperatures and stronger winds.
This has led to the early melting of the sea ice on which emperor penguins nest, sweeping away chicks to their deaths. Numbers of krill and small fish, on which the penguins feed, have also been affected, as the sea ice supports the growth of algae at the bottom of the food chain.
WWF said the plight of emperor penguins and three other species - the Adélie, gentoo and chinstrap - emphasised the need to take effective action to stop the world from warming by more than two degrees above pre-industrial levels.
A WWF document, launched at the United Nations conference on climate change in Bali today, said: "At Pointe Géologie [in the Antarctic], the population has declined by 50 per cent over the past 50 years.
"High mortality occurred during the late 1970s and the [emperor penguin] population has not recovered since. Breeding areas have suffered dramatic changes. Warmer winter temperatures have led to thinner ice which has then been broken up and swept out to sea by frequently stronger winds.
"As a result, emperor eggs and chicks have been blown away before being able to survive on their own."
Dr Simon Walmsley, head of the marine programme at WWF-UK, said he hoped emperor and other penguins would not be among the first major casualties of global warming.
But he added: "In order not to lose penguins, we have got to have major cuts [in emissions]. We are calling for an 80 per cent by 2050 and 40 per cent by 2020. Hopefully that will keep it under the magic two degrees.
"We should be looking at carbon-dioxide cuts to reflect how dangerous this is. If this gets worse, the situation [for the penguins] is bound to get worse."
The Scottish Government has committed to an 80 per cent cut in emissions by 2050, but the UK target is 60 per cent.
Smurf, this doesn't answer that question, but adds a variable that most forget about:How much of the sea level change is due to man-made non-warming related factors? It wouldn't be zero and if this hasn't been included in the models then that ensures they aren't accurate.
Impact of Artificial Reservoir Water Impoundment on Global Sea Level
Originally published in Science Express on 13 March 2008
B. F. Chao,* Y. H. Wu, Y. S. Li
By reconstructing the history of water impoundment in the world's artificial reservoirs, we show that a total of 10,800 cubic kilometers of water has been impounded on land to date, reducing the magnitude of global sea level (GSL) rise by –30.0 millimeters, at an average rate of –0.55 millimeters per year during the past half century. This demands a considerably larger contribution to GSL rise from other (natural and anthropogenic) causes than otherwise required. The reconstructed GSL history, accounting for the impact of reservoirs by adding back the impounded water volume, shows an essentially constant rate of rise at +2.46 millimeters per year over at least the past 80 years. This value is contrary to the conventional view of apparently variable GSL rise, which is based on face values of observation.
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