Times Online

New proof that man has caused global warming
From Mark Henderson, Science Correspondent, in Washington

The strongest evidence yet that global warming has been triggered by human activity has emerged from a major study of rising temperatures in the world’s oceans.



The present trend of warmer sea temperatures, which have risen by an average of half a degree Celsius (0.9F) over the past 40 years, can be explained only if greenhouse gas emissions are responsible, new research has revealed.

The results are so compelling that they should end controversy about the causes of climate change, one of the scientists who led the study said yesterday.

"The debate about whether there is a global warming signal now is over, at least for rational people," said Tim Barnett, of the Scripps Institution of Oceanography in La Jolla, California. "The models got it right. If a politician stands up and says the uncertainty is too great to believe these models, that is no longer tenable."

In the study, Dr Barnett’s team examined more than seven million observations of temperature, salinity and other variables in the world’s oceans, collected by the US National Oceanic and Atmospheric Administration, and compared the patterns with those that are predicted by computer models of various potential causes of climate change.

It found that natural variation in the Earth’s climate, or changes in solar activity or volcanic eruptions, which have been suggested as alternative explanations for rising temperatures, could not explain the data collected in the real world. Models based on man-made emissions of greenhouse gases, however, matched the observations almost precisely.

"What absolutely nailed it was the greenhouse model," Dr Barnett told the American Association for the Advancement of Science conference in Washington. Two models, one designed in Britain and one here in the US, got it almost exactly. We were stunned. They did it so well it was almost unbelieveable."

Climate change has affected the seas in different ways in different parts of the world: in the Atlantic, for example, rising temperatures can be observed up to 700 metres below the surface, while in the Pacific the warming is seen only up to 100m down.

Only the greenhouse models replicated the changes that have been observed in practice. "The fact that this has gone on in different ways gives us the chance to figure out who did it," Dr Barnett said.

"All the potential culprits have been ruled out except one.

"This is perhaps the most compelling evidence yet that global warming is happening right now, and it shows that we can successfully simulate its past and its likely future evolution. The statistical significance of these results is far too strong to be merely dismissed and should wipe out much of the uncertainty about the reality of global warming."

Dr Barnett said the results, which are about to be submitted for publication in a major peer-reviewed journal, should put further pressure on the Bush Administration to sign up to the Kyoto Protocol, which came into force on Wednesday. "It is now time for nations that are not part of Kyoto to reevaluate and see if it would be to their advantage to join," he said.

"We have got a serious problem ahead of us. The debate is not have we got a clear global warming signal, the debate is what we are going to do about it."

In a separate study, also presented to the conference, a team led by Ruth Curry of Woods Hole Oceanographic Institution in Connecticut has established that 20,000 square kilometres of freshwater ice melted in the Arctic between 1965 and 1995.

Further melting on this scale could be sufficient to turn off the ocean currents that drive the Gulf Stream, which keeps Britain up to 6C warmer than it would otherwise be. "It is taking the first steps, the system is moving in that direction," Dr Curry said.

"The new ocean study, taken together with the numberous validations of the same models in the atmosphere, portends far broader changes. Other parts of the world will face similar problems to those expected, and being observed now, in the western US.

"The skill demonstrated by the climate models in handling the changing planetary heat budget suggests that these scenarios have a high enough probability of actually happening that they need to be taken seriously by decision-makers."

http://www.timesonline.co.uk/article/0, ... 55,00.html

Human activities add to the levels of the naturally occuring greenhouse gases.

Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases. The heat-trapping property of these gases is undisputed although uncertainties exist about exactly how earth’s climate responds to them, but scientists know for certain that human activities are changing the composition of Earth's atmosphere.

Increasing levels of greenhouse gases, like carbon dioxide (CO2 ), in the atmosphere since pre-industrial times have been well documented. There is no doubt this atmospheric buildup of carbon dioxide and other greenhouse gases is largely the result of human activities.

I think it was Jon Stewart on the Daily Show that made a pretty funny joke about this one time...

He was saying how the avg temperature of the earth is currently 1.5 degrees warmer than it was 1000 years ago or something....I'd love to know how they gathered that info 1000 years ago....but if that's true, then I'd say we don't really have a global warming problem.

I was asking our other resident scientist. I know what the gases do, he seems undecided.

Certainly there is a CO2 build-up occuring. Will it change the climate? We don't know that. Does the earth have a way of dealing with increasing CO2 levels? probably. CO2 levels have gone up and down throughout the history of the earth, there have been periods where levels were higher than they are now, human influence was not a factor.

I know you do. This was to help him overcome his indecision.

"Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence".
-John Adams

Out of curiousity, kiddo, do you know what the main "greenhouse gas" is?
It makes up over 90% of all the GH gases.

Yes professor, I do. I've been to college and had classes about it and everything.
Now answer the questions.

Scroll up.

The main one is carbon dioxide, and yes it's a naturally occuring greenhouse gas but certain human activities, however, add to the levels of these naturally occurring gases like water vapor, methane, nitrous oxide and ozone.

Can the amount of trees help reduce carbon dioxide?

**looks at picture of Boulder from 1897, looks outside**

There is a crapload of more trees then there was over 100 years ago.

I think that's probably more than made up for by any of the many Colorado-sized chunks of the Amazon basin that are bare now that were lush jungle 100 years ago. This is why you save rainforest, not because it's beautiful or anything gay like that. It's because the rainforests use the CO2 and generate the oxygen for the entire planet.

This is for PJinmyhead.

As you can see, the study you referenced has been discussed before.

To sum:

Tim Burnett's life goal is to prove that the oceans are warming due to man. If he spends millions on a study the results are going to say what he wants (related sub-topic: computer modeling).

It should also be noted, that to date, there has been no paper released on this study, no peer-review, having a press conference months before your paper is released is not exactly good science.

Burnett makes the mysterious comment: "climate models based on air temperatures are weak because most of the evidence for global warming is not even there. The real place to look is in the ocean," One must wonder, what have we been doing the last 20 years? Tim says the evidence for GW is not in the surface models--these are what the gw folks have been using to push there agenda. Tim also made the strange comment that "80% of Greenhouse energy is absorbed by the oceans".
One has to wonder, if this is true, what is the point of even looking at land temperatures for evidence of gw?

Certainly, an increase in ocean temps. is possible, it is a naturally occuring phenomena. How does Burnett link a possible ocean warming with human causes? A computer program, source code written by his team, of course. What data did he ultimately use? How many times was the code "modified". How many runs did it take to get the result he wanted? As I said before, after spending millions of dollars, he's not going to conclude that he's been wrong.

Just link this to the other GW thread, so we don't have a split conversation on it.

Dissappointed.
You're wrong, unfortunately. CO2 makes up less than 3% of GH gases.

So, which one is it? And does the answer have any influence on what we've been discussing?

Water Vapor is by far the most abundant GH gas.
It is, most likely, the reason that most of the computer models thus far have been unable to predict actual data. The models (and by inference, the scientists) do not yet understand the impact of water vapor and clouds on real temps.

So, the question is, since CO2 now makes up 2.8 % of GH gases instead of 2.7%(rough numbers), will it have an effect on climate?

I've never seen a scientist deny the existence of water vapor as a greenhouse gas. What I have seen is equations where water vapor is a relative constant in the global warming equation, and carbon dioxide is a variable. All of these equations are imperfect, of course, but nobody has presented evidence that water vapor is more or less of culprit for warming now than it ever was. What I have heard (from the ice core sampling folks) is that dramatic changes in atmospheric temperature have closely mirrored swings in atmospheric carbon dioxide for millions of years. What should be studied is the difference in how water vapor traps heat, and how carbon dioxide traps heat. Not all greenhouse gases trap heat to the same degree.

What we have to go on is a substantial increase in atmospheric carbon dioxide since the start of the industrial revolution, and we also have a consistent warming trend during that same period. In parts of the world, especially closer to the poles, the warming has been more dramatic. I'm also not sure what the point is of emphasizing ocean warming over atmosphere warming, as one can have a substantial effect on the other, and they end up mirroring each other one way or the other.

Reality.

It is funny that the US use more Gasoline (which we know and is proven to be not exactly good for the environment) than anyone else and is now involved in a war to get more gasoline, but their government and it's people are denying the whole Global Warming phenomenon. Funny that.

And there is no possibility you've been mis-lead at all is there??