rationalskepticism.org

bit_pattern wrote:

Leonidas wrote:

bit_pattern wrote
Yeah, well, I hate to break it to you, Einstein, but sea level is an average, it can vary wildly from ocean to ocean, up to fifteen feet iirc, so just because the pin prick of coast that you happen to have observed has nominally not changed is entirely meaningless. The bigest driver of sea level rise is thermal expansion and, surprise surprise, the greatest sea level rises have been recorded in equatorial regions.

You know I hadn't even considered that. I just sort of assumed that the sea along the coast by my town was at, you know, sea-level. I hadn't even considered the possibility that sea-level had risen in the rest of the world but stayed the same next to my town. It's an amazing world isn't it?


But a question for you. If the sea-level is higher in the rest of the world why doesn't it flow downhill towards me?

It's called physics. Sea level is a mean, and localised sea level can be influenced by the gravitational pull from the Earth's orbit, differences in temperature (war water expands), tides, atmospheric pressures etc. etc. etc.

http://en.wikipedia.org/wiki/Sea_level

And that is only recent up until 2004, as I've already shown, the Greenland ice melt has nearly doubled in that time.

I wonder where all that water is going? It isn't raising sea-level. Perhaps the Chinese are gathering it all behind those dams they are building.

It is raising sea level, you just refuse to accept the evidence. That's why I'm surprised people like you exist on a forum like this, because that isn't scepticism, its denial.

1. To say that and be believed you need to quote the causes of all the previous warming episodes and explain why they don't apply this single time when they account for all of the previous warming events.

2. Climate now is very similar to the way it has been for a long time. If this 'sudden and dramatic..." has had so little effect then more of the same doesn't cause me any concern.

3. Since the CO2 concentrations are historically unprecedented then I presume that previous warmings had nothing to do with CO2.

Well, it's not that hard, the are four major forcings in the Earth's climate:

-- Insolation, the energy input from the sun which can be affected by changes in the Earth's orbit or differences in solar activity. The glacial periods are caused by the orbital shift of the Earth, we can expect another glacial in about 15,000 years, but obviously there hasn't been some yet undiscovered shift in the Earth's orbit, physicists would have noticed. As for solar output, it has been on the decline since the mid-70's when temps diverged from solar activity. If you take the sudden increase in CO2 out and of the data set and model what would have happened over the last thirty years then the planet should be considerably cooler.

-- Albedo, this is energy reflected back into space, either by large areas of light surface (ie. ice caps), or from particulates and aerosols injected into the atmosphere either by large volcano's or pollution. This is a net energy loss.

-- Greenhouse gasses, CO2, NO2, CH4. This is the greenhouse effect, it has been well understood for over 100 years, the physical models have been confirmed by numerous direct experimental evidence, we know the precise rate at which these gasses absorb and emit longwave radiation, we can measure the incoming and outgoing radiation from space and develop global accounting models. This is what keeps the planet from being a very cold ball of ice. Funnily enough, human activity has caused one particular GHG, CO2, to rise by nearly 40%. Everything we know about this molecule says that such an increase should lead to exactly the shift in temperature we have witnessed over the last 30 odd years, and currently the observations fit the basic physical model, ergo, the model is sound.

Finally;

-- Feedbacks, this is where things get slightly murkier. We know that by itself, a doubling of CO2 would lead to a 1 degree rise in temperature, when you take into account the feedback effect from water vapor in the atmosphere we know that should lead to a 2 degree rise in temperature, we know this (although a small minority dispute the sensitivity of CO2 and think there is a much lower range, but they are a minority). Then, when you take into account various other feedbacks, ie. large, reflective areas of ice melting and leaving large areas of dark, absorbent oceans, then scientists estimate another degree or so of warming (although that could be blown right out of the water if the Arctic oceans warm enough to start releasing the vast stores of frozen CH4 on the seabed, and there is good evidence this is already starting to happen, in which case all bets are off).

So there is no known forcing that could possibly explain the lat-20th century warming other than the near 40% rise in CO2, which should cause exactly the sort of event we are witnessing.

That would include Phil Jones's decade of no statistically significant warming I suppose. I suppose it also explains the recent bad winters and cool summers and the recent increase in north polar ice. I don't think that any of that was predicted by the warming models. On the contrary predictions included less snow in winter, continuing polar ice melt and lots of hot summers and awful hurricanes. I don't believe recent climate fits warming predictions.

Phil Jones merely said that a decade wasn't enough time to see a statistically significant trend. Weren't you rabitting on about short term trends earlier? Well, that's exactly what he was getting at before the Daily Mail got hold of it and selevctively quoted him.

And, no, if you actually look at climate model projections, there is a great deal of natural variability (what us common folk call "weather"), there are plenty of runs that show multi-decades of variability, where temps can go up and down even while the planet continues to accumulate heat.

And, it's interesting that you have to use words like "believe", belief needn't come into it, I don't "believe" in global warming, I look at the evidence and make a judgment based on the evidence. Whereas you seem tnot to have looked at the evidence at all.

I think of warming gloom and doom predictions in the same way I think of Nostradamus. At frequent intervals a new version comes out to explain that Nostradamus accurately predicted all sorts of things that have now happened but for the future we are all doomed because the real meaning of what he said is...

Yeah, well, since Nostradamus died we developed a little thing called the scientific method, it's done wonders for the world, in case you hadn't noticed.