Limitations of the 'Scientific Method'

--- In bhascience@yahoogroups.com, "david_c_flint" wrote:
>
> I'm glad you asked me that! I will upload a paper I wrote two years
> ago giving one approach.
>
> dcf
>
>
> --- In bhascience@yahoogroups.com, "Chris Street" chris@ wrote:
> ...
>
> > So what ARE the limitations of the Scientific Method?


David, I think one of the most important limitations of the Scientific Method is (as you say in your upload file) "research often delivers qualified answers whereas citizens and policy makers want definitive answers"

I think terms like 'probably' or 'highly likely', when discussing science, can be used with bullish confidence.

As a corollary, the strength of the scientific method is that current research is provisional and if falsified may be replaced by science that better describes how the world works.

I was very impressed with the 2007 Intergovernmental Panel on Climate Change (IPCC ) final report (pdf) which I reviewed in my Climate Alternative Temperature Science (CATS) blog.

The IPCC considered about 29,000 pieces of real-world evidence and concluded:

Uncertainty

• climate change is "unequivocal"
• Probable temperature rise between 1.8C and 4C
• Possible temperature rise between 1.1C and 6.4C

Likelyhood

• humankind's emissions of greenhouse gases are more than 90% very likely to be the main cause
• Sea level most likely to rise by 28-43cm
• Increase in heat waves very likely
• Increase in tropical storm intensity likely

Confidence

• Changes in snow, ice and frozen ground have with high confidence increased the number and size of glacial lakes
• earlier timing of spring events and poleward and upward shifts in plant and animal ranges
  are with very high confidence linked to recent warming.
  

IPCC defined what they meant by the above terms in red in the IPPC glossary:-

Uncertainty
An expression of the degree to which a value (e.g., the future state of the climate system) is unknown. Uncertainty can result from lack of information or from disagreement about what is known or even knowable. Uncertainty can therefore be represented by quantitative measures, for example, a range of values calculated by various models, or by qualitative statements, for example, reflecting the judgement of a team of experts.

Likelihood
The likelihood of an occurrence, an outcome or a result, where this can be estimated probabilistically, is expressed in IPCC reports using a standard terminology defined as follows:

Terminology Likelihood of the occurrence / outcome
Virtually certain >99% probability of occurrence
Very likely >90% probability
Likely >66% probability
More likely than not >50% probability
About as likely as not 33 to 66% probability
Unlikely <33% probability
Very unlikely <10% probability
Exceptionally unlikely <1% probability

Confidence
The level of confidence in the correctness of a result is expressed in this report, using a standard terminology defined as follows:

Terminology Degree of confidence in being correct
Very high confidence = At least 9 out of 10 chance of being correct
High confidence = About 8 out of 10 chance
Medium confidence = About 5 out of 10 chance
Low confidence = About 2 out of 10 chance
Very low confidence = Less than 1 out of 10 chance

I think this measured language in terms of uncertainty, likelyhood and confidence brilliantly conveys the provisional nature of the scientific method to non-scientists and politicians.

4th and final 2007 IPCC report

Reposted from: http://news.bbc.co.uk/1/hi/sci/tech/7098902.stm

UN challenges states on warming

By Richard Black Environment correspondent, BBC News website, Valencia

The IPCC says more heat waves are very likely in the future

United Nations Secretary General Ban Ki-moon has challenged governments to act on the findings of a major new report on climate change.

Launching the latest report from the Intergovernmental Panel on Climate Change, he said real and affordable ways to deal with the problem existed.

The IPCC states that climate change is "unequivocal" and may bring "abrupt and irreversible" impacts.

Mr Ban urged politicians to respond at a UN climate change conference in Bali.

"Today the world's scientists have spoken clearly and with one voice," he said. "In Bali I expect the world's policymakers to do the same."

Mr Ban arrived at the IPCC meeting in Valencia from a fact-finding trip to Antarctic and South America.

We are all in this together - we must work together Ban Ki-moon Humans blamed for change Billions face climate risk Climate 'can be tackled' Ban Ki-moon

"I come to you humbled after seeing some of the most precious treasures of our planet threatened by humanity's own hand," he said.

"All humanity must assume responsibility for these treasures."

Unavoidable effects

The IPCC report synthesises the three aspects of climate change that it has already pronounced on earlier in the year, on the science, the likely impacts, and options for dealing with the problem.

Among the top-line conclusions are that climate change is "unequivocal", that humankind's emissions of greenhouse gases are more than 90% likely to be the main cause, and that impacts can be reduced at reasonable cost.

READ THE FINDINGS IPCC report [9.3MB]

One declaration that reportedly caused heated discussion during the week-long talks here states that climate change may bring "abrupt and irreversible" impacts.

Such impacts could include the fast melting of glaciers and species extinctions.

"Approximately 20-30% of species assessed so far are likely to be at increased risk of extinction if increases in global average temperature exceed 1.5-2.5C (relative to the 1980-1999 average)," the summary concludes.

Other potential impacts highlighted in the text include:

• between 75m and 250m people are projected to have scarcer fresh water supplies than at present
• yields from rain-fed agriculture could be halved
• food security is likely to be further compromised in Africa
• there will be widespread impacts on coral reefs

The panel's chairman, Rajendra Pachauri, highlighted the need to deal with impacts which are coming whether or not global emissions are curbed.

Even if levels of CO2 in the atmosphere stayed where they are now, he said, research showed sea levels would rise by between 0.4 and 1.4 metres simply because sea water would continue warming up, which makes it expand.

"This is a very important finding, likely to bring major changes to coastlines and inundating low-lying areas, with a great effect in river deltas and low-lying islands," he said.

"If you add to this the melting of some of the ice bodies on Earth, this gives a picture of the kinds of issue we are likely to face."

Worse case

IPCC PROJECTIONS Probable temperature rise between 1.8C and 4C Possible temperature rise between 1.1C and 6.4C Sea level most likely to rise by 28-43cm Arctic summer sea ice disappears in second half of century Increase in heat waves very likely Increase in tropical storm intensity likely Who are the IPCC? Climate change: The evidence Send us your comments

This is the IPCC's fourth major assessment of global climate change since its formation nearly 20 years ago.

During the course of its existence, it has become more certain that modern-day climate change is real and principally due to human activities; it has also become firmer about the scale of the impacts.

"If you look at the overall picture of impacts, both those occurring now and those projected for the future, they appear to be both larger and appearing earlier than we thought [in our 2001 report]," Martin Parry, co-chair of the impacts working group, told BBC News.

"Some of the changes that we previously projected for around 2020 or 2030 are occurring now, such as the Arctic melt and shifts in the locations of various species."

There are indications that projected increases in droughts are also happening earlier than expected, he said, though that was less certain.

The IPCC considered about 29,000 pieces of real-world evidence in compiling this report, as well as the projections of computer models.

These include observations showing that dry areas of the world such as the Sahel and southern Africa are receiving less rainfall, while it has increased in northern Europe and parts of the Americas.

The panel suggests societies need to adapt to future impacts, as well as curbing emissions.

Without extra measures, carbon dioxide emissions will continue to rise; they are already growing faster than a decade ago, partly because of increasing use of coal.

The IPCC's economic analyses say that trend can be reversed at reasonable cost. Indeed, it says, there is "much evidence that mitigation actions can result in near-term co-benefits (e.g. improved health due to reduced air pollution)" that may offset costs.

The panel's scientists say the reversal needs to come within a decade or so if the worst effects of global warming are to be avoided.

The findings will feed into the Bali talks on the UN climate convention and the Kyoto Protocol which open on 3 December.

An inconvenient peace prize

Reposted from: http://commentisfree.guardian.co.uk/bjrn_lomborg/2007/10/an_inconvenient_peace_prize.html

While the IPCC painstakingly establishes what the world should expect from climate change, Al Gore only tells us what to fear.

Björn Lomborg

October 12, 2007 3:36 PM

This year's Nobel peace prize justly rewards the thousands of scientists of the United Nations climate change panel (the IPCC). These scientists are engaged in excellent, painstaking work that establishes exactly what the world should expect from climate change.

The other award winner, former US vice-president Al Gore, has spent much more time telling us what to fear. While the IPCC's estimates and conclusions are grounded in careful study, Gore doesn't seem to be similarly restrained.

Gore told the world in his Academy Award-winning movie (recently labelled "one-sided" and containing "scientific errors" by a British judge) to expect 20-foot sea-level rises over this century. But his Nobel co-winners, the IPCC, conclude that sea levels will rise between only a half-foot and two feet over this century, with their best expectation being about one foot - similar to what the world experienced over the past 150 years.

Likewise, Gore agonises over the accelerated melting of ice in Greenland, but overlooks the IPCC's conclusion that, if sustained, the current rate of melting would add just three inches to the sea level rise by the end of the century. Gore also takes no notice of research showing that Greenland's temperatures were higher in 1941 than they are today.

Gore also frets over a predicted rise in heat-related deaths, without mentioning that rising temperatures will reduce the number of cold spells, which are a much bigger killer than heat. The best study shows that by 2050, heat will claim 400,000 more lives, but 1.8 million fewer will die because of cold. Indeed, global warming will actually save lives.

The IPCC has magnanimously declared that it would have been happy if Gore had received the Nobel peace prize alone. I am glad that he did not.

Unfortunately, Gore's prize will only intensify our focus on climate change to the detriment of other planetary challenges.

Gore concentrates above all else on his call for world leaders to cut CO2 emissions, yet other policies would do much more for the planet. Over the coming century, developing nations will be increasingly dependent on food imports from developed countries, not primarily as a result of global warming, but because of more people and less arable land in the developing world.

The number of hungry people depends much less on climate than on demographics and income. Extremely expensive cuts in carbon emissions could mean more malnourished people. If our goal is to fight malnutrition, policies like getting nutrients to those who need them are 5,000 times more effective at saving lives than spending billions of dollars cutting carbon emissions.

Likewise,

global warming will probably slightly increase malaria, but CO2 reductions will be far less effective at fighting this disease than mosquito nets and medication, which can cheaply save 850,000 lives every year. By contrast, the expensive Kyoto protocol will prevent just 1,400 deaths from malaria each year.

While we worry about the far-off effects of climate change, we do nothing to deal with issues facing the planet today. This year, malnutrition will kill almost 4 million people. Three million lives will be lost to HIV/Aids. Two and a half million people will die because of indoor and outdoor air pollution. A lack of micronutrients and clean drinking water will claim two million lives each.

With attention and money in scarce supply, we should first tackle the problems with the best solutions, thereby doing the most good throughout the century. Focusing on solving today's problems will leave communities strengthened, economies more vibrant, and infrastructures more robust. This will enable us to deal much better with future problems - including global warming - whereas committing to massive cuts in carbon emissions will leave future generations poorer and less able to adapt to challenges.

To be fair, Gore deserves some form of recognition for his resolute passion. However, the contrast between this year's Nobel winners could not be sharper. The IPCC engages in meticulous research where facts rule over everything else. Gore has a very different approach.

In cooperation with Project Syndicate, 2007.

Gore and UN share Nobel peace prize

Reposted from: http://www.guardian.co.uk/environment/2007/oct/12/climatechange.internationalnews

• Mark Tran and Fred Attewill
• Guardian Unlimited
• Friday October 12 2007

Link to this video

The former US vice-president Al Gore and the UN climate change panel will share the 2007 Nobel peace prize for raising awareness of the risks of climate change, the Nobel committee announced today.

Chosen from a field of 181 candidates, Mr Gore and the UN's intergovernmental panel on climate change (IPCC) will split the $1.5m (£750,000) prize.

The Norwegian committee praised Mr Gore for his strong commitment to the struggle against climate change.

Mr Gore responded by telling a press conference that climate change was the "most dangerous challenge we've ever faced".

"I will be doing everything I can to try to understand how to best use the honour and recognition of this award as a way of speeding up the change in awareness and the change in urgency," Mr Gore said.

"It truly is a planetary emergency: we have to respond quickly. I'm going back to work right now. This is just the beginning."

Mr Gore, who lost the 2000 presidential election to George Bush, ignored questions on whether he planned to run again for president.

The Norwegian committee said Mr Gore was "probably the single individual who has done most to create greater worldwide understanding of the measures that need to be adopted".

However, Mr Gore's award-winning film on the issue, An Inconvenient Truth, was this week criticised in a British high court case for allegedly containing inaccuracies.

Mr Gore said he would donate his share of the prize money to the Alliance for Climate Protection, a group seeking to change public opinion in the US and around the world about the urgency of dealing with climate change.

"I am deeply honoured to receive the Nobel peace prize," Mr Gore said in an earlier statement.

"This award is even more meaningful because I have the honour of sharing it with the IPCC - the world's pre-eminent scientific body devoted to improving our understanding of the climate crisis - a group whose members have worked tirelessly and selflessly for many years."

The Nobel committee said the IPCC had created an ever broader, informed consensus about the connection between human activities and global warming.

"Thousands of scientists and officials from over 100 countries have collaborated to achieve greater certainty as to the scale of the warming," the panel said. "Whereas in the 1980s global warming seemed to be merely an interesting hypothesis, the 1990s produced firmer evidence in its support."

The Nobel committee said that by awarding the prize to the IPCC and Mr Gore, it wanted to bring a sharper focus on the processes and decisions needed to protect the world's future climate.

"Action is necessary now, before climate change moves beyond man's control," the panel warned.

The joint award to Mr Gore, who was the favourite among the contenders, is expected to galvanise his supporters, who are pushing him to run again for the White House, despite his loss eight years ago.

Since then, Mr Gore has appeared more relaxed, shedding an uptight image that did him no favours in contrast to Mr Bush, who projected an easygoing charm.

Should Mr Gore take the plunge, he can count on strong grassroots support, though his detractors believe that, in the glare of presidential politics, he will revert to his old, wooden self.

The "draft Gore" movement has been gaining momentum, accumulating about 127,000 signatures this year, 10,000 of them in the last week of September alone.

Mr Gore has consistently said he is not interested in running again for the White House, insisting he can be more effective in the fight against climate change outside mainstream politics.

But his denials of interest have done little to dampen the enthusiasm of supporters, who feel that as president he would have the credibility required to push through tough measures to slow climate change.

The other presidential candidates - Hillary Clinton, in particular - have so far disappointed environmental activists by shying away from promising aggressive action to deal with America's contribution to climate change.

Climate change: In graphics

It is "very likely" that human activity is the cause for climate change, scientists from over 130 countries have concluded. The graphics below illustrate their predictions on just how much global temperatures may rise over the next century.

The Intergovernmental Panel on Climate Change predicts that temperatures are most likely to rise by 1.8C-4C by 2100. But the possible range is much greater; 1.1C-6.4C. The maps above show how a range of three different scenarios will affect different parts of the planet.

The emissions scenarios, A1B, A2, B1, used to create the maps above, are based on a range of detailed economic and technological data. These versions of the future consider different population increases, fossil and alternative fuel use, and consequent CO2 increases. The broad range of outcomes they show is displayed in the charts below.

Carbon dioxide is the main greenhouse gas, its rise since the industrial revolution is clear. Burning coal, using oil and deforestation all place CO2 into the atmosphere.

The other two main greenhouse gases are methane and nitrous oxide. Both gases have a much smaller presence in the atmosphere than CO2 but are much stronger greenhouse gases; methane has over 20 times the effect of C02, while nitrous oxide is nearly 300 times stronger.

Al Gore debates climate change with sceptics

March 21, 2007

---

06:23:43 pm, Categories: Global Warming and Climate Change, Politics and Science, 1374 words

Gore Returns to Senate to Butt Heads With Climate Change Skeptics, Propose Real Solutions

Update: The full video of Gore's testimony before the Senate Environment Committee is now up on the homepage of CSPAN. (Currently it's the second link under "Recent Programs")

As soon as the Democrats took both houses of Congress, one thing became inevitable: Gore was coming back to the Senate, if only to address his all-consuming passion, climate change.

Today at 2:30 EST, Gore got 30 minutes to speak before a packed house. Immediately after, noted climate change skeptic Sen. James Inhofe (R-Oklahoma), who famously declared that global warming "is the greatest hoax ever perpetrated on the American public," got a chance to lay in to the former vice president, at one point even attempting to ambush him by embarrassing him into signing a pledge that he reduce his emissions energy use to that of a typical American household.

Debate

The gloves were off: it was political theater at its finest. Unfortunately, that meant that, save Mr. Gore and, in his better moments, Sen. Inhofe, few of those present addressed the science of climate change in a way that made it sound like they'd done their homework. To wit:

• When Senator Kit Bond (R-Missour) declared that sun spots were just as likely a cause of global warming as human emissions of CO2, I just about fell out of my chair. So did Mr. Gore.

• Sen. Inhofe declared that the Antarctic is gaining ice, not losing it. This makes a nice sound-bite (gee, if the coldest place on earth is growing, not shrinking, doesn't that mean the earth is cooling and not warming, or something?) until you realize that the climate models actually predict increased snowfall over antarctica, mitigating to some extent the sea-level rise that will come about as a result of global warming. It's also worth noting that this data is patchy, at best, and only goes back a few decades.

• Inhofe also whipped out a poster with "over a thousand names" on it of scientists who don't agree with the consensus on global warming. This was a nice touch, but Gore responded appropriately: the IPCC just declared the evidence for anthropogenic climate change to be unequivocal.
  
• the IPCC say "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global
  average sea level" (page 5)
• Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. (page 10) (Summary for Policymakers pdf)
  
• The National Academies of Science of the 16 most developed countries all concurr. In other words, for every name on that poster, there are a dozen, maybe a hundred scientists, maybe more, who don't dispute the basics of anthropogenic climate change. (It was also nice to hear Gore cite the September 2006 single-topic special issue of Scientific American on the future of energy, even if it was only to note that in it the editor in chief declared that the debate on anthropogenic global warming is over.)

  To me, Inhofe's poster o' climate change skeptics is the equivalent of trotting out a bus full of young-earth creationists--sure, there are people on this Earth who think that dinosaurs and humans co-existed, but that doesn't make it so, nor does it mean that there is any real debate about whether or not our planet is 6,000 years old.

To his credit, Inhofe did bring up one point where Gore may have exaggerated in his film: the link between global warming and an increased number of hurricanes. Certainly scientists believe a warmer earth will cause more intense hurricanes. But more hurricanes overall? The jury's still out. Chris Mooney, who is about to come out with a book on just this subject, has more at his blog The Intersection.)

• IPCC say "it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of
  tropical SSTs. There is less confidence in projections of a global decrease in numbers of tropical cyclones. (page 16) (Summary for Policymakers pdf)

Solutions

Some folks may still think this is a political issue, but the many Republican Senators on the Senate Environment committee who were more interested in talking about solutions than debating the science would disagree with those folks. It was gratifying to finally see this becoming a bipartisan issue.

Here is Gore's 9-point plan for dealing with climate change, starting today, directly from his speech:

1) I think we ought to have an immediate freeze on co2 reductions and start from there.

2) We should use the tax code. What I'm about to propose I know is is very much outside the range of what is now politically feasible.

I think we ought to cut taxes on employment and make up the difference with pollution taxes - principally CO2 taxes. Some countries are talking about it seriously.

In the developed world our big disadvantage is that these developed countries have access to tech and container shipping. We don't want to lower our wages - but we don't want to pile on top of those wages these taxes.

We ought to use some of the revenue [from carbon taxes] to help the poor with the adjustments that are coming forward.

3) I'm in favor of cap and trade and I supported Kyoto. but I understand the realities of the situation.

I think the new president should take office at a time when our country has a commitment to defacto compliance with Kyoto. And I think we should move the start of the new treaty period from 2012 to 2010. We need a tougher treaty that starts in 2010. And we need to find a creative way to get China and india involved sooner rather than later.

That's important not least of which because China's emissions will exceed ours in the next couple of years.

We need to ratify a cap and trade system so the market will work for us rather than against us.

4) We should have a moratorium on new coal plants that are not fixed with carbon capture and sequestration technology.

5) I think our congress should fix a date beyond which incandescent lightbulbs are banned. [aside: Australia is about to do this.]...

It's like wal-mart. It's not taking on the climate crisis simply out of the goodness of their heart. They care about it but they're making money at it.

6) The creative power of the information revolution was unlocked by the Internet.

We ought to have [an analogous] electro-net and we ought to encourage widely distributed power generation. We ought to take off the caps and let individuals sell back as much as they want on the grid.

7) I think we ought to raise the CAFE standards. Don't single out autos, but as part of it.

8) Pass a carbon-neutral mortgage association. Here's why: buyers of new homes and buyers and sellers all focus on purchase prices. But the expenditures that go into more insulation and window treatment and those that don't pay back immediately but pay back over 2-3 years, those don't get counted as savings. Put those in a separate instrument - then have a Connie May [like the government's Fannie Mae, which handles mortgages] which can create a separate instrument. So that people can save and reduce co2 at the same time.

9) Require corporate disclosure of carbon emissions. Investors have a right to know about material risks that could affect the value of their stocks in the future.

reposted from: sciam
my: highlights / emphasis / key points / comments

IPCC Climate report released

Key climate report sparks global call to action

• 18:02 02 February 2007
• NewScientist.com news service
• Catherine Brahic, Paris

Governments and environmental groups the world over have greeted the new UN report on the science of climate change with words of praise – and determination. The report, by the Intergovernmental Panel on Climate Change, was released on Friday in Paris, France (see Blame for global warming placed firmly on humankind).

"It is another nail in the coffin of the climate change deniers and represents the most authoritative picture to date, showing that the debate over the science of climate change is well and truly over,” said David Miliband, UK environment minister.

The report considered all the research since the last IPCC assessment in 2001 and the 21-page summary (pdf) of its findings – approved by officials from 113 countries – says that “warming of the climate system is unequivocal”.

“The IPCC report embodies an extraordinary scientific consensus that climate change is already upon us, and that human activities are the cause,” says James Leape, director general of WWF International.

Achim Steiner, executive director of the United Nations' Environment Programme (one of the governing bodies of the IPCC), said the new report "gives us a stark warning that the potential impact will be more dramatic, faster and more drastic in terms of consequences" than previously thought. The impacts will change the way some people live in fundamental ways, he added.

Calls for action

Despite past scepticism by the US administration, the White House backed the report. "It is a comprehensive and accurate reflection of the current state of climate change science,” said Sharon Hays, associate director of the White House Office of Science and Technology Policy. Hays led the US delegation to the IPCC, which was praised by many for their constructive contribution to the final vetting of the report summary.

With the report being acknowledged as having clearly demonstrated the link between human activities and climate change, it has prompted strong calls for action.

The Democrat chair of the House Committee on Science and Technology, Bart Gordon said: "Expert scientists have provided us with a diagnosis of the problem and a prognosis for our planet's health. Now, it's time for us - the policymakers - to do our jobs."

"The clock is ticking and time is running out for us to avoid major climate change, with the real and serious threats to our economies and peoples' livelihoods it carries,” said Marthinus van Schalwyk, South African minister for environment and tourism.

"Faced with this emergency, now is not the time for half measures. It is the time for a revolution, in the true sense of the term," said French president Jacques Chirac. "We are in truth on the doorstep of the irreversible."

Post Kyoto

There was a hopeful feeling in Paris that the new report would pave the way for an agreement that would go beyond the Kyoto Protocol targets for 2012.

Yvo de Boer, executive secretary to the UN Framework Convention on Climate Change, said the European Commission’s calls for industrialised nations to reduce their greenhouse gas emissions by 60% to 80% by 2050 (compared to 1990 levels) were “exactly in line with what scientists say we need". The question now, he said, "is how do we convince other industrialised countries to sign up to the European rallying call?”

Others echoed the idea that developed nations must take the lead. Kenneth Denman, a Canadian climatologist who led the work on one of the report’s chapters, told New Scientist that developed countries would be “moral hypocrites if we ask developing countries to reduce their emissions when they’re trying to catch up with the standard of living we’ve had for the past 50 years”.

“North America has 5% of the global population,” Denman pointed out, “yet we produce 25% of the fossil fuel emissions.” Developed nations must “clean up their act” first, he said.

reposted from: NS
my: highlights / emphasis / key points / comments

Climate change predictions go from bad to worse - IPCC report

IT TOOK three years to write and contains six years' worth of research. The full report, to be published later this year, will contain 11 chapters. One chapter alone, seen by New Scientist, runs to 150 pages and includes more than 850 references. The authors say it will resolve many critical questions about climate change and support the unequivocal language of the summary published last week.

Warming is now an "incontrovertible" fact for two reasons, the scientists say. First, because doubts raised by satellite data - which suggested that recent warming has been far less than surface thermometers indicate - have now been resolved. In short, the thermometers have been shown to be right (New Scientist, 20 August 2005, p 10). In any case, nothing else but global warming can explain the rapid melting of ice round the world.

The declaration that warming is "very likely" to be due to human activity is justified by an increasing agreement between measurements from the real world and the detailed predictions of statistical models of warming. "It is a very rigorous statistical analysis, comparing measurements and models in space and time in a more detailed way than ever before," says Susan Solomon, head of the US group that led the assessment. Key to this has been the observed greater warming over land masses compared with the oceans, and the combination of warming in the lower atmosphere with cooling in the stratosphere.

Researchers also claim to have a better idea of how much warming from greenhouse gases is being masked by dust and smoke aerosols put into the air by human activity. This again improves the match between models and the real world.

The team is also much more confident now about the unique nature of recent warming. The IPCC's 2001 summary report was heavily criticised for including a graph - known as the "hockey stick" - which purported to show that the world is now warmer than for at least the past 1000 years. The claim was based on sporadic proxy data such as tree rings, and was widely attacked. Now a huge amount of extra data collected since 2001 "all supports the interpretation that warming in the past half-century is unusual in at least the last 1300 years", the summary says.

Where does this leave the prognosis for the planet? The report sets the likely range of average temperature changes for a doubling of carbon dioxide concentrations - expected around the end of the century - at between 2 and 4.5 °C. This is roughly in line with previous reports, though this time it adds, with a nod to possible positive feedbacks, "values substantially higher than 4.5 °C cannot be excluded".

This amount of warming will likely deliver an ice-free Arctic and a 30 per cent drop in rainfall in many subtropical regions, including a huge area from the Mediterranean and North Africa through the Middle East to central Asia, and another across southern Africa. Meanwhile, higher latitudes will get wetter as the air warms and storm tracks move, and hurricanes will become more intense.

Global warming, the report says, contains a deadly time lag. That's because 80 per cent of the extra heat currently being trapped by man-made greenhouse gases is being drawn into the oceans. As the oceans warm, more of that heat will remain in the air. Even if emissions of greenhouse gases were sharply reduced, the world would continue to warm by 0.1 °C per decade for some time.

From issue 2590 of New Scientist magazine, 10 February 2007, page 9

The solar effect

It is one of the few areas where the sceptics' argument has had some force. What role has the sun played in recent climate change? As if to underline the controversy, last week's debate on this issue lasted some 10 hours.

The IPCC scientists wanted to halve their previous estimate of the maximum possible solar influence on warming over the past 250 years, from 40 per cent to 20 per cent. Government delegations from China and Saudi Arabia refused to accept that, based on new ideas about cosmic rays from outer space.

Cosmic rays ionise the atmosphere, which could, the theory goes, create clouds. Thus, anything that reduces the amount of cosmic rays could diminish cloud cover and so warm the Earth's surface. An increase in solar activity would do just that - by deflecting cosmic rays away from Earth. China and Saudi Arabia were buoyed by claims that small changes in radiation from the sun could be amplified by their potential effect on clouds. Thus, they said, the sun could have a greater effect than the scientists claimed.

Most climate scientists are unconvinced. "Right now there is no evidence," says IPCC author Piers Forster of the University of Leeds, UK. In any case, IPCC scientists believe, most of today's warming can be explained by man-made influences (see Charts). But with a book due from solar-radiation proponent Henrik Svensmark of the Danish National Space Center, this may not be the end of the matter.

reposted from: new scientist
my: highlights / emphasis / key points / comments

IPCC Climate report 'was watered down'

• 08 March 2007
• Exclusive from New Scientist Print Edition. Subscribe and get 4 free issues
• Fred Pearce

British researchers who have seen drafts of last month's report by the Intergovernmental Panel on Climate Change claim it was significantly watered down when governments became involved in writing it.

David Wasdell, an independent analyst of climate change who acted as an accredited reviewer of the report, says the preliminary version produced by scientists in April 2006 contained many references to the potential for climate to change faster than expected because of "positive feedbacks" in the climate system. Most of these references were absent from the final version.

His assertion is based on a line-by-line analysis of the scientists' report and the final version, which was agreed last month at a week-long meeting of representatives of more than 100 governments. Wasdell told New Scientist: "I was astounded at the alterations that were imposed by government agents during the final stage of review. The evidence of collusional suppression of well-established and world-leading scientific material is overwhelming."

He has prepared a critique, "Political Corruption of the IPCC Report?", which claims: "Political and economic interests have influenced the presented scientific material." He publish the document online this week at www.meridian.org.uk/whats.htm.

Wasdell is not a climatologist, but his analysis was supported this week by two leading UK climate scientists and policy analysts. Ocean physicist Peter Wadhams of the University of Cambridge, who made the discovery that Arctic ice has thinned by 40 per cent over the past 25 years and also acted as a referee on the IPCC report, told New Scientist: "The public needs to know that the policy-makers' summary, presented as the united words of the IPCC, has actually been watered down in subtle but vital ways by governmental agents before the public was allowed to see it."

"The public needs to know that the summary has been watered down in subtle but vital ways by governmental agents"

Crispin Tickell, a long-standing UK government adviser on climate and a former ambassador to the UN, says: "I think David Wasdell's analysis is very useful, and unique of its kind. Others have made comparable points but not in such analytic detail."

Wasdell's central charge is that "reference to possible acceleration of climate change [was] consistently removed" from the final report. This happened both in its treatment of potential positive feedbacks from global warming in the future and in its discussion of recent observations of collapsing ice sheets and an accelerating rise in sea levels.

For instance, the scientists' draft report warned that natural systems such as rainforests, soils and the oceans would in future be less able to absorb greenhouse gas emissions. It said: "This positive feedback could lead to as much as 1.2 °C of added warming by 2100." The final version does not include this figure. It acknowledges that the feedback could exist but says: "The magnitude of this feedback is uncertain."

Similarly, the draft warned that warming will increase atmospheric levels of water vapour, which acts as a greenhouse gas. "Water vapour increases lead to a strong positive feedback," it said. "New evidence estimates a 40 to 50 per cent amplification of global mean warming." This was absent from the published version, replaced elsewhere with the much milder observation "Water vapour changes represent the largest feedback."

The final edit also removed references to growing fears that global warming is accelerating the discharge of ice from major ice sheets such as the Greenland sheet. This would dramatically speed up rises in sea levels and may already be doing so. The 2006 draft said: "Recent observations show rapid changes in ice sheet flows," and referred to an "accelerating trend" in sea-level rise. Neither detail made the final version, which observed that "ice flow from Greenland and Antarctica... could increase or decrease in future". Wasdell points out recent findings which show that the rate of loss from ice sheets is doubling every six years, making the suggestion of a future decrease "highly unlikely".

Some of the changes were made at the meeting of government invigilators that finalised the report last month in Paris. But others were made earlier, after the draft report was first distributed to governments in mid-2006.

Senior IPCC scientists contacted by New Scientist have not been willing to discuss how any changes took place but they deny any political interference. However, "if it is true, it's disappointing", says Mike Mann, director of the Earth System Science Center at Pennsylvania State University in University Park and a past lead author for the IPCC. "Allowing governmental delegations to ride into town at the last minute and water down conclusions after they were painstakingly arrived at in an objective scientific assessment does not serve society well."

From issue 2594 of New Scientist magazine, 08 March 2007, page 10

reposted from: New Scientist
my: highlights / emphasis / key points / comments

Behind the scenes at the Paris climate change meeting

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• IPCC final 2007 report (2nd Feb released) Scientist & Governmental concensus report says 90% (9/10) chance (ie. very likely) that climate change is caused by man
• Chinese & Saudia Arabia delegation argued that their was a 66% chance (likely) that climate change is caused by man. NB. The "likely" term was used in the final IPCC 2001 report. The Chinese arguement was dismissed in the final 2007 IPCC report.
• US delegation was cooperative and constructive
• unequivocal evidence that global warming is happening
  

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my: highlights / emphasis / key points / comments

Scientific Method used in IPCC Climate Change report

The Intergovernmental Panel on Climate Change (IPCC) report was issued February 2007. Certain terms are used and defined to represent scientifically objective statements (eg Very Likely >90% chance).

In general, uncertainty ranges for results given in this Summary for Policymakers are 90% uncertainty intervals unless stated otherwise, i.e., there is an estimated 5% likelihood that the value could be above the range given in square brackets and 5% likelihood that the value could be below that range. Best estimates are given where available. Assessed uncertainty intervals are not always symmetric about the corresponding best estimate. Note that a number of uncertainty ranges in the Working Group I TAR corresponded to 2-sigma (95%), often using expert judgement. (page 2)

In this Summary for Policymakers, the following terms have been used to indicate the assessed likelihood, using expert judgement, of an outcome or a result (page 4):

• Virtually certain > 99% probability of occurrence
• Extremely likely > 95%
• Very likely > 90%
• Likely > 66%,
  
• More likely than not > 50%
• Unlikely <33%>
• Very unlikely <10%
• Extremely unlikely <5%

Examples

• Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. This is an advance since the TAR’s 2001 conclusion that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”.
  

In this Summary for Policymakers the following levels of confidence (page 5) have been used to express expert judgments on the correctness of the underlying science:

• very high confidence at least a 9 out of 10 chance of being correct
• high confidence about an 8 out of 10 chance of being correct.
  

Examples

• The understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming

Unequivocal example: Warming of the climate system is unequivocal, (not defined) as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.

Reference: Intergovernmental Panel on Climate Change IPCC pdf report