• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

Global Warming & Climate Change: The Phenomenon

I agree with that; CO2 is a relatively small contributor to global climate, and several other effects are responsible for the wild swings we have seen in the Quaternary era. Humans have been lucky - for the last three thousand years or so, we have had a reasonably stable climate. This has not always been the case, even during the period during which modern Humans have existed on Earth.

But anthropogenic CO2 is significant, in a small way, and as an entirely new factor it could become highly significant. We are adrift on a vast ocean of climate, and our boat is tossed this way and that by the random forces of astronomical and geological effects. But we have hoisted a sail- CO2 emissions- and this sail will consistently blow us in one direction only, towards a warmer world. We might be affected by other, larger forcings in the meantime- but that little human-derived effect is consistently blowing us one way.

When I'm being optimistic, I imagine that this anthropgenic effect will fizzle out before we are badly affected- after all, fossil fuels are going to run out soon, aren't they?

Yes, fossil fuels might run out sooner, rather than later, and we won't have to worry about CO2 any more. But the main reason that fossil fuels might run out rapidly is that developing and newly developed countries such as China and India are likely to use them up quite rapidly in the next few decades, releasing a pulse of CO2 into the atmosphere - this would be the equivalent of hoisting several more sails on the little boat I described earlier.
 
eburacum said:
We are adrift on a vast ocean of climate, and our boat is tossed this way and that by the random forces of astronomical and geological effects. But we have hoisted a sail- CO2 emissions- and this sail will consistently blow us in one direction only, towards a warmer world.
Click to expand...
An interesting nautical analogy! But I have to point out that in the world of real sails, progress is not made 'in one direction only', but in any desired direction, including upwind! (The Olympic sailing events would be rather dull otherwise!)

Interestingly, the most progress is made across the wind, rather than down-wind, but I can't see that this fits with any AGW scenario! ;) Perhaps we need to introduce imaginary numbers... no, let's not go there!
 
Thanks, Cap'n!

I suppose my analogy would only work for someone in a coracle, or some other kind of keel-less boat.

Perhaps that's what we need to do- build a keel of some sort. Here's what we use in Orion's Arm, when we want to control the weather...
http://www.orionsarm.com/eg-article/4f9fb6b195cda
this sort of kit is probably at least a hundred years in the future, if it is possible at all, so I wouldn't put too much faith in this, or any other kind of hi-tech fix...
 
eburacum said:
I agree with that; CO2 is a relatively small contributor to global climate, and several other effects are responsible for the wild swings we have seen in the Quaternary era. Humans have been lucky - for the last three thousand years or so, we have had a reasonably stable climate. This has not always been the case, even during the period during which modern Humans have existed on Earth.

But anthropogenic CO2 is significant, in a small way, and as an entirely new factor it could become highly significant. We are adrift on a vast ocean of climate, and our boat is tossed this way and that by the random forces of astronomical and geological effects. But we have hoisted a sail- CO2 emissions- and this sail will consistently blow us in one direction only, towards a warmer world. We might be affected by other, larger forcings in the meantime- but that little human-derived effect is consistently blowing us one way.

When I'm being optimistic, I imagine that this anthropgenic effect will fizzle out before we are badly affected- after all, fossil fuels are going to run out soon, aren't they?

Yes, fossil fuels might run out sooner, rather than later, and we won't have to worry about CO2 any more. But the main reason that fossil fuels might run out rapidly is that developing and newly developed countries such as China and India are likely to use them up quite rapidly in the next few decades, releasing a pulse of CO2 into the atmosphere - this would be the equivalent of hoisting several more sails on the little boat I described earlier.
Click to expand...


It all comes down to the amplification question doesn't it. If we start with the assumption that CO2 is responsible for all the perceived recent warming (which it probably isn't or may not be, but still, let's assume for argument) then the question of whether it's going to be a problem rests on the issue of positive feedback. Without that amplifier the increase for a doubling of CO2 is a bit over 1 degreeC. And the increase is logarithmic, meaning the amount of increase drops sharply as a proportion of the whole as the overall amount increases.

So, without a positive feedback amplifier we don't have a global warming "problem" - even if AGW is real. The warming will simply never be enough to make a significant amount of difference.

How likely is the positive feedback amplification? The "mainstream" view is it's very likely. But this is largely because the mainstream view has been constructed by modelers or by those working with models. They've created a virtual climate that runs at very high sensitivity and throws out warming estimates of between 3 and 6 degrees C based on positive feedback from water vapor etc. But this is a model. There's actually virtually no hard real-world evidence that high degrees of positive feedback like this have ever functioned in past climate.

There's the rub. If you think of models as being real evidence then there's masses of evidence for positive amplification that will lead to dangerous warming. if you think of them as being just tools for playing out ideas, then there's no evidence for positive amplification at all.

Can models be taken as evidence? i don't see how they can. Especially not if they contradict observed real world data. And that's good. It means global warming is probably one thing we don't have to worry about.:)
 
Rio+20: Sir Paul backs Greenpeace Arctic campaign
By Richard Black, Environment correspondent, BBC News, Rio de Janeiro

Greenpeace is launching a campaign to have the Arctic region declared a sanctuary by the United Nations.
The group aims for a million signatures on a petition calling for an end to oil exploration and unsustainable fishing, which will be planted on the sea bed.
Celebrities such as Sir Paul McCartney, actor Robert Redford and the boy band One Direction are among the backers.

The move comes as a response to what the environment group regards as the "epic failure" of the Rio+20 summit.
The summit aimed to put the global economy on a more sustainable footing - enhancing economic wealth, especially for the poorest on earth, while protecting the environment.

"The fightback starts here," said Kumi Naidoo, executive director of Greenpeace International.
"The Arctic is coming under assault, and needs people from around the world to stand up and demand action to protect it.
"A ban on offshore oil drilling and unsustainable fishing would be a huge victory against the forces ranged against this precious region and the four million people who live there."

Mr Naidoo, who previously campaigned to end apartheid in his native South Africa, told the Guardian newspaper on the fringes of the Rio+20 summit that Greenpeace was moving to a "war footing" as a result of the Rio outcome.
The first 100 signatories on the new petition include explorers, business leaders, actors and musicians.

Film director Pedro Almodovar and his sometime leading lady Penelope Cruz, Radiohead frontman Thom Yorke, actor Javier Bardem and businessman Sir Richard Branson are on the list unveiled at Rio+20.

"It seems madness that we are willing to go to the ends of the earth to find the last drops of oil when our best scientific minds are telling us we need to get off fossil fuels to give our children a future," said Sir Paul.
"At some time, in some place, we need to take a stand. I believe that time is now and that place is the Arctic."

Thom Yorke added: "An oil spill in the Arctic would devastate this region of breathtaking beauty, while burning that oil will only add to the biggest problem we all face, climate change."

Another signatory, Xena and Battlestar Galactica actress Lucy Lawless, is due to be sentenced in September for blocking operations on a Shell oil rig in the Arctic earlier this year.

The Arctic is warming up faster than almost any other part of the planet.
The area of ocean covered by sea ice each summer is shrinking. If current trends continue, it will set a new record low for the satellite era this year.
As the sea ice recedes, it becomes easier for companies to prospect for oil and gas, with the US, Canada, Greenland and Russia among countries pursuing this nascent industry.

Greenpeace is calling for an agreement to ban environmentally damaging activities in the Arctic region, just as they were banned in the Antarctic 21 years ago under a protocol added to the Antarctic Treaty.

It is not the first organisation to call for such an agreement. Proposals date back to the 1970s, but have never gained political traction.

In 2007, acting under instruction from Moscow, explorer Artur Chilingarov planted a Russian flag on the seabed beneath the pole, laying claim to the area.
The Greenpeace action aims to counteract that by planting a scroll signed by at least a million people in the same place, claiming it as a sanctuary.

http://www.bbc.co.uk/news/science-environment-18531697
 
It probably does make sense to try and protect the Arctic to some extent. Maybe Paul McCartney could buy it and turn it into a polar bear theme park.

The article is a bit misleading though when it says "the Arctic is warming faster than anywhere else". I mean it's probably broadly true, but it's phrased to make it seem like the whole world is wildly heating up and the Arctic is ahead of this crazy curve. But actually the Arctic is warming "faster" partly because some places aren't warming much if at all. Which is why the average global temp has been almost static for about fifteen years.

Meanwhile the Antarctic has been doing everyone's heads in by cooling on one side and warming on the other without anyone knowing why. It's quite funny watching both sides trying to make that fit their POV. The hardline Mark Morano-type Skeptics point to the cooling and say "look, cooling, global warming is crap", and the hardline Warmists subtract the warming in the west from the cooling in the east and say "on average it's getting warmer" as if that somehow explains something. :D

New record cold temp out there recently:

http://amrc.ssec.wisc.edu/news/index.php?id=41

South Pole New Temperature Record
Posted: 2012-06-18
South Pole Station Antarctica

June 11th: The temperature of -73.8°C/-100.8°F broke the previous minimum temperature record of -73.3°C/-99.9°F set in 1966.
Click to expand...
 
AngelAlice said:
South Pole New Temperature Record
Posted: 2012-06-18
South Pole Station Antarctica

June 11th: The temperature of -73.8°C/-100.8°F broke the previous minimum temperature record of -73.3°C/-99.9°F set in 1966.
Click to expand...
Click to expand...

Well it is the middle of winter down there after all.
 
Cavynaut said:
AngelAlice said:
South Pole New Temperature Record
Posted: 2012-06-18
South Pole Station Antarctica

June 11th: The temperature of -73.8°C/-100.8°F broke the previous minimum temperature record of -73.3°C/-99.9°F set in 1966.
Click to expand...
Click to expand...

Well it is the middle of winter down there after all.
Click to expand...

Quite - if there was a new record cold temp in summer that really would be news. but how would the Grauniad spin it to support AGW? -

"Record summer cold in Antarctic Confirms Climate Change" - and a pic of a penguin looking depressed.

;)
 
AngelAlice said:
Cavynaut said:
AngelAlice said:
South Pole New Temperature Record
Posted: 2012-06-18
South Pole Station Antarctica

June 11th: The temperature of -73.8°C/-100.8°F broke the previous minimum temperature record of -73.3°C/-99.9°F set in 1966.
Click to expand...
Click to expand...

Well it is the middle of winter down there after all.
Click to expand...

Quite - if there was a new record cold temp in summer that really would be news. but how would the Grauniad spin it to support AGW? -

"Record summer cold in Antarctic Confirms Climate Change" - and a pic of a penguin looking depressed.

;)
Click to expand...
They'd probably just mention this:
http://antarcticsun.usap.gov/features/contenthandler.cfm?id=2563


Heat wave
South Pole hits record high temperature on Christmas Day

Arctic Sun. By Peter Rejcek, Antarctic Sun Editor. Posted December 29, 2011. Updated January 1, 2012

A rare white Christmas at the South Pole brought with it a record-breaking heat wave — at least for a day.

The temperature officially hit 9.9 degrees Fahrenheit (minus 12.3 degrees Celsius) about 3:50 p.m. on Dec. 25, according to South Pole Station External U.S. government site senior meteorologist Phillip Marzette. That shattered the old record of 7.5F (minus 13.6C) set on Dec. 27, 1978 — though technically that record had been broken on Christmas Eve, Dec. 24, 2011, when the temperature climbed to 8.1F (minus 13.3C). (All dates and times are local, based on the New Zealand time zone.)

Those sorts of temperatures may not qualify as mild to some people, but consider that the average annual temperature at the South Pole is about minus 56.9F (minus 49.4C). In the summer, from late October to early February, the average is closer to minus 26F (minus 32C), Marzette said.

“We like to call this our little Christmas miracle that we ended up getting snow and getting a record high for the books,” Marzette said a few days after the record-breaking day, when temperatures had returned to mid-summer norms, about minus 15F (minus 26C).

The snow was certainly an unexpected bonus. Precipitation in the continental interior is normally very light. Ice crystals are the most common form of precipitation at the South Pole. Ice crystals often fall out of a clear sky, glittering like tiny diamonds in the sunshine, and sometimes creating atmospheric phenomena like sundogs.

Larger snow grains often accompany storms, while actual snowflakes usually only occur at the height of summer, from mid-December to mid-January, when temperatures are at their warmest.

The cause of the sudden spike in temperature was a system from what’s called grid south of the research station, bringing winds of up to 13 miles per hour. It’s very uncommon to get wind from that direction, according to Marzette.

(The South Pole Station grid system uses Cartesian coordinates, which specify each point uniquely in a plane by a pair of numerical coordinates. Grid north at Pole is defined as the line representing the prime meridian or zero line of longitude and is called “north.” The 180-degree line from South Pole is referred to as “south.”)

When the system did blow through, the temperature started to rise rapidly, beginning at around 6 a.m. on Dec. 25, after starting just below 0F. By 3:50 p.m., the mercury had climbed to 9.9F, and hit the mark again around 10:50 p.m., before dropping as quickly on the following day.

Matthew Lazzara External Non-U.S. government site, director of the Antarctic Meteorological Research Center (AMRC) External Non-U.S. government site at the University of Wisconsin-Madison External Non-U.S. government site, reported on the AMRC blog External Non-U.S. government site that two nearby automatic weather stations (AWS) External Non-U.S. government site, dubbed Nico and Henry, had also reported record high temperatures.

The preliminary assessment of the data from those two sites, about 60 miles to the grid east (Nico) and grid north (Henry) of the South Pole, show that the Nico AWS hit 17.2F (minus 8.2C) and the Henry AWS reached 16F (minus 8.9C) on Dec. 25. The previous record at the former was 7F (minus 13.9C) on Jan. 4, 2010, while the Henry AWS had recorded a previous high of 5.9F (minus 14.5C) on Jan. 5, 2010.

The warmest temperature ever recorded in Antarctica occurred on Jan. 5, 1974, hitting a balmy 59F (15C), at Vanda Station, a small research base that once operated on the shores of Lake Vanda in the McMurdo Dry Valleys External U.S. government site.

The Russian Vostok Station still holds the record for coldest temperature — not just in Antarctica but the world. On July 21, 1983, the mercury bottomed out at minus 128.6F (minus 89.2 °C). The coldest day at the South Pole was minus 117F (minus 82.8C) on June 23, 1982.
Click to expand...
 
Lighten up P - I'm just joking.

It'd be a pic of a polar bear, not a penguin ;)
 
Significant sea-level rise in a 2-degree warming world

June 24th, 2012 in Space & Earth / Earth Sciences

The study is the first to give a comprehensive projection for this long perspective, based on observed sea-level rise over the past millennium, as well as on scenarios for future greenhouse-gas emissions.

"Sea-level rise is a hard to quantify, yet critical risk of climate change," says Michiel Schaeffer of Climate Analytics and Wageningen University, lead author of the study. "Due to the long time it takes for the world's ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come."

Limiting global warming could considerably reduce sea-level rise
While the findings suggest that even at relatively low levels of global warming the world will have to face significant sea-level rise, the study also demonstrates the benefits of reducing greenhouse-gas emissions. Limiting global warming to below 1.5 degrees Celsius and subsequent temperature reductions could halve sea-level rise by 2300, compared to a 2-degree scenario. If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.

The potential impacts are significant. "As an example, for New York City it has been shown that one metre of sea level rise could raise the frequency of severe flooding from once per century to once every three years," says Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, co-author of the study. Also, low lying deltaic countries like Bangladesh and many small island states are likely to be severely affected.
Sea-level rise rate defines the time for adaptation

The scientists further assessed the rate of sea-level rise. The warmer the climate gets, the faster the sea level climbs. "Coastal communities have less time to adapt if sea-levels rise faster," Rahmstorf says.

"In our projections, a constant level of 2-degree warming will sustain rates of sea-level rise twice as high as observed today, until well after 2300," adds Schaeffer, "but much deeper emission reductions seem able to achieve a strong slow-down, or even a stabilization of sea level over that time frame."

Building on data from the past

Previous multi-century projections of sea-level rise reviewed by the Intergovernmental Panel on Climate Change (IPCC) were limited to the rise caused by thermal expansion of the ocean water as it heats up, which the IPCC found could reach up to a metre by 2300. However, this estimate did not include the potentially larger effect of melting ice, and research exploring this effect has considerably advanced in the last few years. The new study is using a complementary approach, called semi-empirical, that is based on using the connection between observed temperature and sea level during past centuries in order to estimate sea-level rise for scenarios of future global warming.

"Of course it remains open how far the close link between temperature and global sea level found for the past will carry on into the future," says Rahmstorf. "Despite the uncertainty we still have about future sea level, from a risk perspective our approach provides at least plausible, and relevant, estimates."

Provided by Potsdam Institute for Climate Impact Research (PIK)

"Significant sea-level rise in a 2-degree warming world." June 24th, 2012. http://phys.org/news/2012-06-significan ... world.html
Click to expand...
 
More on sea-level rise.
http://www.guardian.co.uk/environment/2012/jun/24/us-east-coast-sea-level-rise

Scientists warn US east coast over accelerated sea level rise

Study says sea level is rising far faster than elsewhere, which could increase incidence of New York flooding

guardian.co.uk, Damian Carrington. 24 June 2012

Sea level rise is accelerating three to four times faster along the densely populated east coast of the US than other US coasts, scientists have discovered. The zone, dubbed a "hotspot" by the researchers, means the ocean from Boston to New York to North Carolina is set to experience a rise up a third greater than that seen globally.

Asbury Sallenger, at the US geological survey at St Petersburg, Florida, who led the new study, said: "That makes storm surges that much higher and the reach of the waves that crash onto the coast that much higher. In terms of people and communities preparing for these things, there are extreme regional variations and we need to keep that in mind. We can't view sea level rise as uniform, like filling up a bath tub. Some places will rise quicker than others and the whole urban corridor of north-east US is one of these places."

The hotspot had been predicted by computer modelling, but Sallenger said: "Our paper is the first to focus on using real data to show [the acceleration] is happening now and that we can detect it now."

The rapid acceleration, not seen before on the Pacific of Gulf coasts of the US, may be the result of the slowing of the vast currents flowing in the Altantic, said Sallenger. These currents are driven by cold dense water sinking in the Arctic, but the warming of the oceans and the flood of less dense freshwater into the Arctic from Greenland's melting glaciers means the water sinks less quickly. That means a "slope" from the fastest-moving water in the mid-Atlantic down to the US east coast relaxes, pushing up sea level on the coast.

"Coastal communities have less time to adapt if sea levels rise faster," said Stefan Rahmstorf, at the Potsdam Institute Germany, who published a separate study in the same journal, Nature Climate Change, on Sunday. Rahmstorf's team showed that even relatively mild climate change, limited to 2C, would cause global sea level to rise between 1.5 and 4 metres by the year 2300. If nations acted to cutting carbon emissions so the temperature rise was only 1.5C, the sea level rise would be halved, the researchers found.

The impacts of the rising seas are potentially devastating, said the scientists. "As an example, 1 metre of sea level rise could raise the frequency of severe flooding for New York City from once per century to once every three years," said Rahmstorf, adding that low lying countries like Bangladesh are likely to be severely affected. His colleague Michiel Schaeffer, at Wageningen University in the Netherlands, said: "Sea level rise is a hard to quantify, yet a critical risk of climate change. Due to the long time it takes for the world's ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come."

Sallenger's work on the hotspot off the US east coast showed that the extreme acceleration in sea level rise could add 20-30% to the rise seen globally. "If this turns out to be a metre by 2100, it would add 20 to 30cm." In May, North Carolina legislators drew ridicule from experts by proposing a law that would require estimates of sea level rise to be based solely on historical data and to rule out any acceleration in future rises.

Rahmstorf said: "Sallenger's paper shows that, far from being spared accelerating sea level rise, [the coast here] has been over the past decades a hotspot of accelerating sea level rise." But he added that the cause of the hotspot was not fully understood, meaning it was uncertain whether the acceleration would continue.

Sallenger said: "We came up with a very clear correlation between the acceleration of sea level rise and rising temperature in the hotspot area. That suggests to me that as long as temperature continues to rise the hotspot will continue to grow."
Click to expand...
Emphasis mine

They may have to change New York's name back to New Amsterdam.
 
I realise there may be some contention over the accuracy of the fossil record, but it is certainly useful (and interesting) to see temperature vs CO2 plotted for the prehistoric era:

http://www.biocab.org/Geological_Timescale.jpg

If you look across this vast timescale, you can see that there isn't any clear correlation between CO2 levels and temperature. In fact, the only part where there does appear to be a correlation is in the most recent era (in the Quaternary).

CO2 levels are actually pretty low right now - 394.45 ppmv (0.039445%).
Levels of CO2 in previous geological eras have been much, much higher.

Current climate change models only take about 60 years of data into consideration.
I think it's simply not enough data from which to extrapolate long-term temperature trends.
In fact, the 60 years of data we are using may well be statistically insignificant.

But... what do I know, I am not a scientist or statistician. :)
 
Mythopoeika said:
I realise there may be some contention over the accuracy of the fossil record, but it is certainly useful (and interesting) to see temperature vs CO2 plotted for the prehistoric era:

http://www.biocab.org/Geological_Timescale.jpg

If you look across this vast timescale, you can see that there isn't any clear correlation between CO2 levels and temperature. In fact, the only part where there does appear to be a correlation is in the most recent era (in the Quaternary).

CO2 levels are actually pretty low right now - 394.45 ppmv (0.039445%).
Levels of CO2 in previous geological eras have been much, much higher.

Current climate change models only take about 60 years of data into consideration.
I think it's simply not enough data from which to extrapolate long-term temperature trends.
In fact, the 60 years of data we are using may well be statistically insignificant.

But... what do I know, I am not a scientist or statistician. :)
Click to expand...

Yes. There are considerable anomalies in places with the CO2/temperature line up. It doesn't necessarily mean there's no connection, but it does imply CO2 might be a relatively weak force compared to others.

It just underlines the whole absurdity of trying to sell CAGW as some sort of proven entity. We'll just have to hope reality prevails before anything too appallingly Malthusian is done by the well-meaning but misinformed.
 
ExxonMobil CEO says burning fossil fuels is warming the planet.

http://thetyee.ca/Blogs/TheHook/Environment/2012/06/28/exxon-fossil-fuel-adapt-climate/

direct link to speech http://www.cfr.org/united-states/new-north-american-energy-paradigm-reshaping-future/p28630
"So I'm not disputing that increasing CO2 emissions in the atmosphere is going to have an impact. It'll have a warming impact. "

"TILLERSON: Well, let me -- let me say that we have studied that issue and continue to study it as well. We are and have been long-time participants in the IPCC panels. We author many of the IPCC subcommittee papers, and we peer-review most of them."
 
How global warming is driving our weather wild
09 July 2012 by Stephen Battersby

Not only is global weather becoming much more extreme, it is becoming even more extreme than anyone expected

ITS NICKNAME is the icebox of the nation. The village of Pellston in Michigan often sees arctic winters, with a thermometer-shattering record low of -47 °C in 1933. Even by late March, it is usually a very chilly place. But not this year. On 22 March the Pellston weather station registered a temperature above 29 °C, vaporising the previous record for that date by more than 17 degrees.

This was just one of thousands of weather records smashed by the "summer in March", a 10-day event that affected much of North America. [And UK!] Many people enjoyed the unseasonal warmth, but most of the other extraordinary weather events of the past decade have been far less welcome. In 2003, the summer in Europe was so hot it killed tens of thousands. Russia in 2010 suffered even more staggering heat. Rainstorms brought unprecedented floods to Pakistan in 2010 and again in 2011. Tropical cyclone Gonu in 2007 was the most powerful ever recorded in the Arabian Sea.

Climate scientists have long warned that global warming will lead to more heatwaves, droughts and floods. Yet some of these recent extremes, such as the summer in March, are way beyond the predictions of our climate models. And there have been extremes of cold as well as heat. In Rome, ancient monuments are crumbling because of the big freeze that hit Europe this February. And on the northern edge of the Sahara desert, the streets of Libya's capital Tripoli were blanketed with snow.

It seems that our weather is getting wilder - more variable as well as steadily hotter. The big question is why. Is this just a blip, or are we in for even more freakish weather as global warming accelerates over the coming decades?

Even in an unchanging climate, our weather varies a lot. Each summer will be different. Take the average summer temperature each year, and you will get a series of numbers scattered about a long-term mean, distributed in a pattern more or less like a bell curve. Wait long enough, and you will sweat though a few very hot summers and grumble through a few very cool summers.

Over the past century, the surface temperature of the planet has increased by 0.8 °C on average, which has shifted the familiar range of weather into warmer territory. Cooler summers have become less likely and warmer summers more likely. Contrary to what you might think, this kind of shift increases the odds of extremely hot summers by more than it increases the odds of slightly warmer summers (see "Shifting weather").

The rising temperature is leading to other kinds of extreme weather, too. Warmer air can hold more moisture - in fact, its capacity increases exponentially as the temperatures rises. This means that when rain falls it can become a deluge, increasing the chance of catastrophic floods (New Scientist, 19 March 2011, p 44).

Floods are not the only result. When water vapour condenses to form clouds, it releases latent heat, and this heat is what powers most kinds of storms, from thunderstorms to hurricanes. With a wetter atmosphere there may not necessarily be more storms, but those that do occur will tend to be more powerful because there is more heat to power them. The damage done by storms rises rapidly as wind speeds increase.

So simple physics tells us that global warming should make extreme weather more extreme, from stronger storms to hotter heatwaves, drier droughts and damper downpours. This is indeed what has been happening around the world - except that in recent years, the magnitude of some of the record breakers has been jaw-dropping.

In 2003, temperatures in Europe were much higher than any summer for at least 500 years. Stefan Rahmstorf of the Potsdam Institute in Germany points out that in Switzerland the average summer temperature broke the previous record by 2.4 °C. It is not unusual for the records for particular days to be broken by fairly wide margins but for the average of an entire season to be so much warmer is extraordinary. Then there was the Russian heatwave of 2010. Even averaged over Europe as a whole, this heatwave was more extreme than the one in 2003.

Most recently, there was the summer in March. Because it was so early in the year, it was a disaster only for fruit growers - trees blossomed too early and then got hit by frost, wiping out over 90 per cent of crops in some places - but it could have been much worse. "If such unusual conditions had occurred during July or August, the impact would have been enormous," says Dim Coumou, a colleague of Rahmstorf.

etc... (You need to be registered with NS to read full article.)

http://www.newscientist.com/article/mg2 ... -wild.html?
 
http://www.newscientist.com/article...gest-roman-world-was-warmer-than-thought.html

Tree rings suggest Roman world was warmer than thought

How did the Romans manage to grow grapes in northern England when most climate studies suggest the weather was much cooler then? We may now have an answer: it wasn't that cold at all.

Long-term temperature reconstructions often rely on the width of tree rings: they assume that warmer summers make for wider rings. Using this measure, it seems that global temperatures changed very little over the past two millennia. Such studies are behind the famous "hockey stick" graph, created by Michael Mann of Pennsylvania State University in University Park, which shows stable temperatures for a millennium before the 20th century.
Click to expand...

Full text at link.
 
Iceberg breaks off from Greenland's Petermann Glacier

The Petermann Glacier in northern Greenland has calved an iceberg twice the size of Manhattan, scientists say.
Images from a Nasa satellite show the island breaking off a tongue of ice that extends at the end of the glacier.

In 2010 an ice island measuring 250 square km (100 square miles) broke off the same glacier.
Glaciers do calve icebergs naturally, but the extent of the changes to the Petermann Glacier in recent years has taken many experts by surprise.
"It is not a collapse but it is certainly a significant event," Eric Rignot from Nasa said in a statement.

Some other observers have gone further. "It's dramatic. It's disturbing," University of Delaware's Andreas Muenchow told the Associated Press.
"We have data for 150 years and we see changes that we have not seen before," Mr Muenchow added.

However, the calving is not expected have an impact on sea levels as the ice was already floating.
Icebergs from the Petermann Glacier sometimes reach the coast off Newfoundland in Canada, posing a danger to shipping and navigation, according to the Canadian Ice Service.

Scientists have also raised concerns in recent years about the Greenland ice shelf, saying that it is thinning extensively amid warm temperatures.

http://www.bbc.co.uk/news/world-europe-18896770
 
Satellites reveal sudden Greenland ice melt

Greenland's massive ice sheet has melted this month over an unusually large area, Nasa has said.
Scientists said the "unprecedented" melting took place over a larger area than has been detected in three decades of satellite observation.
Melting even occurred at Greenland's coldest and highest place, Summit station.
The thawed ice area jumped from 40% of the ice sheet to 97% in just four days from 8 July.

Although about half of Greenland's ice sheet normally melts over the summer months, the speed and scale of this year's melting surprised scientists, who described the phenomenon as "extraordinary".

Nasa said that nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its centre, which is 3km (two miles) thick, experienced some degree of melting at its surface.

"When we see melt in places that we haven't seen before, at least in a long period of time, it makes you sit up and ask what's happening," Nasa chief scientist Waleed Abdalati said.
"It's a big signal, the meaning of which we're going to sort out for years to come."

He said that, because this Greenland-wide melting has happened before, Nasa is not yet able to determine whether this is a natural but rare event, or if it has been sparked by man-made global warming.
Scientists said they believed that much of Greenland's ice was already freezing again.

Until now, the most extensive melting seen by satellites in the past three decades was about 55% of the area.
Ice last melted at Summit station in 1889, ice core records show.

The news comes just days after Nasa satellite imagery revealed that a massive iceberg, twice the size of Manhattan, had broken off a glacier in Greenland.
"This event, combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story," said Nasa's Tom Wagner.

http://www.bbc.co.uk/news/world-europe-18978483
 
Loss of Arctic sea ice '70% man-made'
Study finds only 30% of radical loss of summer sea ice is due to natural variability in Atlantic – and it will probably get worse
Alok Jha, science correspondent
The Guardian, Thursday 26 July 2012

The radical decline in sea ice around the Arctic is at least 70% due to human-induced climate change, according to a new study, and may even be up to 95% down to humans – rather higher than scientists had previously thought.

The loss of ice around the Arctic has adverse effects on wildlife and also opens up new northern sea routes and opportunities to drill for oil and gas under the newly accessible sea bed.
The reduction has been accelerating since the 1990s and many scientists believe the Arctic may become ice-free in the summers later this century, possibly as early as the late 2020s.

"Since the 1970s, there's been a 40% decrease in the summer sea ice extent," said Jonny Day, a climate scientist at the National Centre for Atmospheric Science at the University of Reading, who led the latest study.
"We were trying to determine how much of this was due to natural variability and therefore imply what aspect is due to man-made climate change as well."

To test the ideas, Day carried out several computer-based simulations of how the climate around the Arctic might have fluctuated since 1979 without the input of greenhouse gases from human activity.
He found that a climate system called the Atlantic multi-decadal oscillation (AMO) was a dominant source of variability in ice extent. The AMO is a cycle of warming and cooling in the North Atlantic that repeats every 65 to 80 years – it has been in a warming phase since the mid-1970s.

Comparing the models with actual observations, Day was able to work out what contribution the natural systems had made to what researchers have observed from satellite data.
"We could only attribute as much as 30% [of the Arctic ice loss] to the AMO," he said. "Which implies that the rest is due to something else, and this is most likely going to be man-made global change."

Previous studies had indicated that around half of the loss was due to man-made climate change and that the other half was due to natural variability.
Looking across all his simulations, Day found that the 30% figure was an upper limit – the AMO could have contributed as little as 5% to the overall loss of Arctic ice in recent decades.
The research is published online in the journal Environmental Research Letters.

Day said that there are a number of feedback effects that could see the Arctic ice loss continue in the coming years, as the Earth warms up.
"[There is] something called the ice-albedo feedback, which means that when you have less ice, it means there's more open water and therefore the ocean absorbs more radiation and will continue to warm," he said.
"It's unclear what will happen – it definitely seems like it's going in that direction."

http://www.guardian.co.uk/world/2012/ju ... ate-change
 
Mediterranean earthworm species found thriving in Ireland as global temperatures rise
July 25th, 2012 in Biology / Ecology


This is a P. amplisetosus in soil in the urban farm Dublin, Ireland. Credit: Carol Melody, UCD

Scientists have discovered a thriving population of Mediterranean earthworms in an urban farm in Dublin, Ireland.

The findings by University College Dublin scientists published in the journal Biology Letters on 25 July 2012 suggest that rising soil temperatures due to climate change may be extending the geographical habitat range of the earthworm Prosellodrilus amplisetosus.

"Soil decomposer species including earthworms are frequently introduced into non-native soils by human activities like the transportation of nursery plants or live fish bait," says Dr Olaf Schmidt from the School of Agriculture and Food Science, and the Earth Institute, University College Dublin, one of the authors of the report.

"There have been a few recordings of the earthworm P. amplisetosus outside of its native range in the Aquitaine region of south-western France, but now we have discovered a successfully thriving population in Ireland, about 1,000 km north of its native habitat."


This is a Prosellodrilus amplisetosus in soil in urban farm in Dublin, Ireland, where scientists have discovered a thriving population of the earthworm. Credit: Carol Melody, UCD

Urban farms have higher temperatures than rural farms so the scientists suggest that this may have helped P. amplisetosus to become established in this new location. The mean yearly air temperature in Aquitaine in south-western France is about 3 degrees higher than in Dublin, Ireland.

The finding brings to 27 the total number of known earthworm species living in Irish soils.

According to the scientists, the Mediterranean species of earthworm P. amplisetosus is not an invasive species in Ireland. It does not directly compete for resources with the other resident species.

"By comparing the chemical composition of the worms, we discovered that the newcomers feed on a portion of the soil that the other resident earthworms do not use," says Carol Melody, a PhD student at the School of Agriculture and Food Science, University College Dublin, who co-authored the research paper.

"P. amplisetosus is a soil decomposer that eats organic carbon in portions of the soil to which the resident worm species don't have access," she says.

"If other soil decomposers like P. amplisetosus start to expand their habitat ranges we could see increasing amounts of CO2 being released from the soil where previously this carbon had been locked up because it was inaccessible to native earthworm species," says Dr Schmidt.

A sample of the P. amplisetosus found thriving in Dublin, Ireland, has been deposited in the Natural History Museum in London to archive the scientific discovery and to make scientists in Britain aware of the southern vagrants.

Provided by University College Dublin

"Mediterranean earthworm species found thriving in Ireland as global temperatures rise." July 25th, 2012. http://phys.org/news/2012-07-mediterran ... lobal.html
Click to expand...
 
Palm trees 'grew on Antarctica'
By Jason Palmer, Science and technology reporter, BBC News

Scientists drilling deep into the edge of modern Antarctica have pulled up proof that palm trees once grew there.
Analyses of pollen and spores and the remains of tiny creatures have given a climatic picture of the early Eocene period, about 53 million years ago.
The study in Nature suggests Antarctic winter temperatures exceeded 10C, while summers may have reached 25C.
Better knowledge of past "greenhouse" conditions will enhance guesses about the effects of increasing CO2 today.

The early Eocene - often referred to as the Eocene greenhouse - has been a subject of increasing interest in recent years as a "warm analogue" of the current Earth.
"There are two ways of looking at where we're going in the future," said a co-author of the study, James Bendle of the University of Glasgow.
"One is using physics-based climate models; but increasingly we're using this 'back to the future' approach where we look through periods in the geological past that are similar to where we may be going in 10 years, or 20, or several hundred," he told BBC News.

The early Eocene was a period of atmospheric CO2 concentrations higher than the current 390 parts per million (ppm )- reaching at least 600ppm and possibly far higher.
Global temperatures were on the order of 5C higher, and there was no sharp divide in temperature between the poles and the equator.

Drilling research carried out in recent years showed that the Arctic must have had a subtropical climate.
But the Antarctic presents a difficult challenge. Glaciation 34 million years ago wiped out much of the sediment that would give clues to past climate, and left kilometres of ice on top of what remains.

Now, the Integrated Ocean Drilling Program (IODP) has literally got to the bottom of what the Eocene Antarctic was like, dropping a drilling rig through 4km of water off Wilkes Land on Antarctica's eastern coast.
The rig then drilled through 1km of sediment to return samples from the Eocene. With the sediment came pollen grains from palm trees and relatives of the modern baobab and macadamia.

Crucially, they contained also the remnants of tiny single-celled organisms called Archaea.
The creatures' cell walls show subtle molecular changes that depend on the temperature of the soil surrounding them when they were alive. The structures are faithfully preserved after they die.
They are, in essence, tiny buried thermometers from 53 million years ago.

Together, the data suggest that even in the darkest period of Antarctic winter, the temperature did not drop below 10C; and summer daytime temperatures were in the 20Cs.
The lowland coastal region sported palm trees, while slightly inland, hills were populated with beech trees and conifers.

Dr Bendle said that as an analogue of modern Earth, the Eocene represents heightened levels of CO2 that will not be reached any time soon, and may not be reached at all if CO2 emissions abate.

However, he said the results from the Eocene could help to shore up the computer models that are being used to estimate how sensitive climate is to the emissions that will certainly rise in the nearer term.
"It's a clearer picture we get of warm analogues through geological time," he said.
"The more we get that information, the more it seems that the models we're using now are not overestimating the [climatic] change over the next few centuries, and they may be underestimating it. That's the essential message."

http://www.bbc.co.uk/news/science-environment-19077439
 
Extreme summer heat linked to climate change, scientists say

Exceedingly high summer temperatures, longer summers and related catastrophes, such as wildfire and drought, are poised to be the norm, and they are driven by climate change, according to a new research paper published Monday in the Proceedings of the National Academy of Sciences.

In an opinion article over the weekend in the Washington Post that previewed the findings, the paper’s lead author, James E. Hansen wrote: “It is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change.”

The longtime director of the NASA Goddard Institute for Space Studies, Hansen was among the first scientists to warn about climate change and its potential effects during a 1988 Senate hearing. He now says he was mistaken in one critical way: “I was too optimistic.” The effects of climate change are being felt now, not in a distant future, he said.
Click to expand...
Full article -

http://www.latimes.com/news/science/sci ... ?track=rss
 
Some pre-historical findings.

Cold spell gripped Europe 3,000 years before 'Little Ice Age,' says study
August 6th, 2012 in Space & Earth / Earth Sciences

Irene Schimmelpfennig sampled moraines on Switzerland’s Tsidjiore Nouve Glacier in 2010 to measure its movement over the last 10,000 years.

(Phys.org) -- Human civilization arose during the relatively balmy climate of the last 10,000 years. Even so, evidence is accumulating that at least two cold spells gripped the northern hemisphere during this time, and that the cooling may have coincided with drought in the tropics. Emerging research on climate during this Holocene period suggests that temperature swings were more common than previously thought, and that climate changes happened on a broad, hemispheric scale.

In a new study in Geology, Irene Schimmelpfennig, a postdoctoral researcher at Columbia University’s Lamont-Doherty Earth Observatory, and her colleagues find that one glacier in the Western Alps was bigger than today during at least two periods in the last 10,000 years—during the well-documented Little Ice Age between 1300 AD and 1850 AD, and at an earlier time, from 3,800 to 3,200 years ago.

Between 2006 and 2010, Schimmelpfennig and colleagues traveled to Switzerland’s Tsidjiore Nouve Glacier to collect rocks dragged downhill by past advancing glaciers. As temperatures warmed and the ice retreated, the ridges of rock or sediment, or moraines, left behind were bombarded by cosmic rays.

Irene Schimmelpfennig sampled moraines on Switzerland’s Tsidjiore Nouve Glacier in 2010 to measure its movement over the last 10,000 years.

By analyzing the chemical make-up of these rocks, scientists can estimate when the glacier retreated. At Tsidjiore Nouve Glacier, Schimmelpfennig found signs of the earlier cold snap from 3,800 to 3,200 years ago. This cold period also shows up in climate records collected elsewhere in the European Alps. From seafloor sediments retrieved off Venezuela, scientists can see that the two cold spells in the north coincided with a drying in the tropics as the rain belt that circles earth’s equator pushed south. “The glacier’s behavior is not a regional response to regional changes in precipitation, said Schimmelpfennig, a member of Lamont’s Cosmogenic Dating Group. “There must be a driver on the hemispheric scale.”

Schimmelpfennig will continue collecting rocks in the Alps to document Holocene climate shifts at the mid-latitudes.

Provided by Columbia University

"Cold spell gripped Europe 3,000 years before 'Little Ice Age,' says study." August 6th, 2012. http://phys.org/news/2012-08-cold-europ ... e-age.html
Click to expand...
 
Nothing to do with the thrust of the article, but - Irene Schimmelpfennig! I so want to meet her. What a fabulous name.
 
Rate of arctic summer sea ice loss is 50% higher than predicted
New satellite images show polar ice coverage dwindling in extent and thickness
Robin McKie Science Editor
guardian.co.uk, Saturday 11 August 2012 21.52 BST

Sea ice in the Arctic is disappearing at a far greater rate than previously expected, according to data from the first purpose-built satellite launched to study the thickness of the Earth's polar caps.
Preliminary results from the European Space Agency's CryoSat-2 probe indicate that 900 cubic kilometres of summer sea ice has disappeared from the Arctic ocean over the past year.

This rate of loss is 50% higher than most scenarios outlined by polar scientists and suggests that global warming, triggered by rising greenhouse gas emissions, is beginning to have a major impact on the region. In a few years the Arctic ocean could be free of ice in summer, triggering a rush to exploit its fish stocks, oil, minerals and sea routes.

Using instruments on earlier satellites, scientists could see that the area covered by summer sea ice in the Arctic has been dwindling rapidly. But the new measurements indicate that this ice has been thinning dramatically at the same time. For example, in regions north of Canada and Greenland, where ice thickness regularly stayed at around five to six metres in summer a decade ago, levels have dropped to one to three metres.

"Preliminary analysis of our data indicates that the rate of loss of sea ice volume in summer in the Arctic may be far larger than we had previously suspected," said Dr Seymour Laxon, of the Centre for Polar Observation and Modelling at University College London (UCL), where CryoSat-2 data is being analysed. "Very soon we may experience the iconic moment when, one day in the summer, we look at satellite images and see no sea ice coverage in the Arctic, just open water."

The consequences of losing the Arctic's ice coverage, even for only part of the year, could be profound. Without the cap's white brilliance to reflect sunlight back into space, the region will heat up even more than at present. As a result, ocean temperatures will rise and methane deposits on the ocean floor could melt, evaporate and bubble into the atmosphere. Scientists have recently reported evidence that methane plumes are now appearing in many areas. Methane is a particularly powerful greenhouse gas and rising levels of it in the atmosphere are only likely to accelerate global warming. And with the disappearance of sea ice around the shores of Greenland, its glaciers could melt faster and raise sea levels even more rapidly than at present.

Professor Chris Rapley of UCL said: "With the temperature gradient between the Arctic and equator dropping, as is happening now, it is also possible that the jet stream in the upper atmosphere could become more unstable. That could mean increasing volatility in weather in lower latitudes, similar to that experienced this year."

etc...

http://www.guardian.co.uk/environment/2 ... -vanishing
 
Arctic sea ice set to hit record low
By Mark Kinver, Environment reporter, BBC News

Arctic sea ice looks set to hit a record low by the end of the month, according to satellite data.
Scientists at the US National Snow and Ice Data Center said data showed that the sea ice extent was tracking below the previous record low, set in 2007.
Latest figures show that on 13 August ice extent was 483,000 sq km (186,000 sq miles) below the previous record low for the same date five years ago.

The ice is expected to continue melting until mid- to late September.
"A new daily record... would be likely by the end of August," the centre's lead scientist, Ted Scambos, told Reuters.
"Chances are it will cross the previous record while we are still in ice retreat."

Sea ice extent refers to a measurement of the area of Arctic Ocean that contains at least some sea ice. Areas with less than 15% are considered by scientists to mark the ice edge.

In its latest summary, the centre said the average rate of ice loss since late June had been "rapid", with just over 100,000 sq km melting each day.
However, it added, the rate of loss doubled for a few days earlier this month during a major storm.

Responding to the latest update, Prof Seymour Laxon, professor of climate physics at University College London, said that he was not surprised that 2012 was set to deliver a record minimum.
"We got very close to a record minimum last year," he told BBC News.
"The fact that Cryosat showed thinner ice last winter, it is not surprising to me that it looks like we will have a record minimum this year."

Cryosat is a radar spacecraft operated by the European Space Agency (Esa) that was launched in 2010 to monitor changes in the thickness and shape of polar ice.

Prof Laxon added that this year's projected record minimum could result in a change in projections of when the Arctic would be sea ice-free during summer months.
"The previous [Intergovernmental Panel on Climate Change] report (published in 2007) stated that the likely date for an ice-free Arctic in the summer - and definitions for this vary a bit - was 2100," he explained.

"When we had the 2007 minimum, that date was brought forward to 2030-2040.
"The fact that we look set to get another record ice minimum in such a short space of time means that the modellers may once again need to go and look at what their projections are telling them."

Arctic sea ice plays a key role in help keep polar regions cool and helps control the global climate system.
As the ice has a bright surface, it reflects about 80% of the sunlight that hits it back into space.
When the sea ice melts, it exposes more of the dark ocean surface, resulting in 90% of the sunlight being absorbed, which warms the Arctic ocean.

http://www.bbc.co.uk/news/science-environment-19330307
 
Long article, includes 3 video clips, etc.

Arctic ice melting at 'amazing' speed, scientists find
By David Shukman, Science Editor, BBC News, in Svalbard

Scientists in the Arctic are warning that this summer's record-breaking melt is part of an accelerating trend with profound implications.
Norwegian researchers report that the sea ice is becoming significantly thinner and more vulnerable.
Last month, the annual thaw of the region's floating ice reached the lowest level since satellite monitoring began, more than 30 years ago.
It is thought the scale of the decline may even affect Europe's weather.

The melt is set to continue for at least another week - the peak is usually reached in mid-September - while temperatures here remain above freezing.

The Norwegian Polar Institute (NPI) is at the forefront of Arctic research and its international director, Kim Holmen, told the BBC that the speed of the melting was faster than expected.
"It is a greater change than we could even imagine 20 years ago, even 10 years ago," Dr Holmen said.
"And it has taken us by surprise and we must adjust our understanding of the system and we must adjust our science and we must adjust our feelings for the nature around us."

The institute has been deploying its icebreaker, Lance, to research conditions between Svalbard and Greenland - the main route through which ice flows out of the Arctic Ocean.
During a visit to the port, one of the scientists involved, Dr Edmond Hansen, told me he was "amazed" at the size and speed of this year's melt.
"As a scientist, I know that this is unprecedented in at least as much as 1,500 years. It is truly amazing - it is a huge dramatic change in the system," Dr Hansen said.
"This is not some short-lived phenomenon - this is an ongoing trend. You lose more and more ice and it is accelerating - you can just look at the graphs, the observations, and you can see what's happening."

I interviewed Dr Hansen while the Lance was docked at Norway's Arctic research station at Ny-Alesund on Svalbard.

Key data on the ice comes from satellites but also from measurements made by a range of different techniques - a mix of old and new technology harnessed to help answer the key environmental questions of our age.

The Norwegians send teams out on to the floating ice to drill holes into it and extract cores to determine the ice's origin.
And since the early 90s they have installed specialist buoys, tethered to the seabed, which use sonar to provide a near-constant stream of data about the ice above.

An electro-magnetic device known as an EM-Bird has also been flown, suspended beneath a helicopter, in long sweeps over the ice.
The torpedo-shaped instrument gathers data about the difference between the level of the seawater beneath the ice and the surface of the ice itself.
By flying transects over the ice, a picture of its thickness emerges. The latest data is still being processed but one of the institute's sea ice specialists, Dr Sebastian Gerland, said that though conditions vary year by year a pattern is clear.
"In the region where we work we can see a general trend to thinner ice - in the Fram Strait and at some coastal stations."

Where the ice vanishes entirely, the surface loses its usual highly reflective whiteness - which sends most solar radiation back into space - and is replaced by darker waters instead which absorb more heat.
According to Dr Gerland, additional warming can take place even if ice remains in a far thinner state.

"It means there is more light penetrating through the ice - that depends to a high degree on the snow cover but once it has melted the light can get through," Dr Gerland said.
"If the ice is thinner there is more light penetrating and that light can heat the water."

etc...

http://www.bbc.co.uk/news/world-europe-19508906
 
Global warming: the heat’s back on
Protecting the ozone layer means the next step must be the control of damaging HFCs
By Geoffrey Lean
8:45PM BST 14 Sep 2012

[Article starts with a review of the discovery of the Antarctic Ozone Hole, then continues...]
The discovery of the “ozone hole” caused alarm, because a thinly scattered stratospheric layer of the blue-tinged gas is all that protects terrestrial life from lethal ultraviolet solar rays. For more than a decade, some scientists had worried that CFCs, used in a huge range of products from foams to aerosol cans, were eroding it – and, sure enough, observations soon showed they were to blame.

International negotiations on tackling ozone depletion, which had been sputtering along without much practical progress, suddenly sprang into life, with Ronald Reagan’s United States leading the drive for urgent action. On September 16 1987, 24 countries signed the Montreal Protocol. Its original measures were modest and agreement on them was so hard-won that it was not translated from English into the five other official UN languages – as is normal practice – for fear that the inevitable change in nuances would cause it to collapse.

But it took off: time and again participating nations tightened the targets, phasing out CFCs and a host of other ozone-damaging chemicals.
All 197 UN countries have now ratified it – the first treaty of any kind to have gained universal membership. It covers some 100 substances and reduces their total production by nearly 98 per cent. The ozone layer will still take decades to heal, but potential disaster has been averted.

Yet by a strange symmetry, as the pact’s 25th anniversary is marked, a similar shock is under way at the other end of the earth. This weekend, Arctic sea ice is nearing its annual minimum, reaching an unprecedentedly small 3.5 million square kilometres in extent. This is a massive 650,000 square kilometres beneath its previous record low, in September 2007 – and that in itself represented a drop to levels not expected to result from global warming until 2050.

The ice now covers little more than half the area it did at this time of year in the 1980s and 1990s. And it is also getting thinner; in all, there is only about 30 per cent as much ice as three decades ago. Many scientists say the Arctic could soon be ice-free, for the first time in millions of years.

When, and if, that happens, the shock may finally galvanise the sclerotic international climate- change negotiations, but it is likely then to be too late to avoid enormous, if incalculable, consequences. Yet, curiously, the Montreal Protocol may provide the best chance of taking rapid action in the meantime.
Indeed, it has already achieved more than two decades of climate talks, since CFCs and other ozone depleters also contribute to global warming: phasing them out has been five times as effective as the Kyoto Protocol in tackling climate change.

Unfortunately, the chemicals increasingly being employed in their place, HFCs, are themselves exceptionally potent greenhouse gases, and their rise threatens to undo all the progress made in tackling global warming so far. Frustratingly, they come under the aegis of the climate talks and so are caught up in the logjam that bedevils those negotiations. More than 100 countries want them to be brought under the Montreal Protocol, which is much more likely to take action – but this is being blocked by India and China, which have large HFC industries, with support from Brazil.

It will come to a head at a Protocol meeting in November. Making the change and controlling HFCs would be the fastest and cheapest available means of mitigating global warming, a fitting way of marking the anniversary of a momentous pact.

http://www.telegraph.co.uk/earth/enviro ... ck-on.html
 
You must log in or register to reply here.
Back
Top