The UNREAL climate change thread

Page 2 of 25 Previous  1, 2, 3 ... 13 ... 25  Next

View previous topic View next topic Go down

Re: The UNREAL climate change thread

Post  Guest on Thu Dec 01, 2011 12:38 am


Guest
Guest


Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Thu Dec 01, 2011 3:18 am

That is without a doubt definitive proof of climate change. cheers

But is it "man-made" climate change? Suspect It very well might be.

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Tue Dec 06, 2011 6:11 pm

pinhedz wrote:No polar bear? scratch


Steve Bell. The Guardian.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  Andy on Wed Dec 07, 2011 7:26 am

Source: http://www.giss.nasa.gov/research/briefs/hansen_15/

Earth's Climate History: Implications for Tomorrow

By James E. Hansen and Makiko Sato — July 2011


Humans lived in a rather different world during the last ice age, which peaked 20,000 years ago. An ice sheet covered Canada and parts of the United States, including Seattle, Minneapolis and New York City. The ice sheet, more than a mile thick on average, would have towered over today's tallest buildings. Glacial-interglacial climate oscillations were driven by climate forcings much smaller than the human-made forcing due to increasing atmospheric CO2 — but those weak natural forcings had a long time to operate, which allowed slow climate feedbacks such as melting or growing ice sheets to come into play

The past is the key to the future. Contrary to popular belief, climate models are not the principal basis for assessing human-made climate effects. Our most precise knowledge comes from Earth's paleoclimate, its ancient climate, and how it responded to past changes of climate forcings, including atmospheric composition. Our second essential source of information is provided by global observations today, especially satellite observations. which reveal how the climate system is responding to rapid human-made changes of atmospheric composition, especially atmospheric carbon dioxide (CO2). Models help us interpret past and present climate changes, and, in so far as they succeed in simulating past changes, they provide a tool to help evaluate the impacts of alternative policies that affect climate.

Paleoclimate data yield our best assessment of climate sensitivity, which is the eventual global temperature change in response to a specified climate forcing. A climate forcing is an imposed change of Earth's energy balance, as may be caused, for example, by a change of the sun's brightness or a human-made change of atmospheric CO2. For convenience scientists often consider a standard forcing, doubled atmospheric CO2, because that is a level of forcing that humans will impose this century if fossil fuel use continues unabated.

We show from paleoclimate data that the eventual global warming due to doubled CO2 will be about 3°C (5.4°F) when only so-called fast feedbacks have responded to the forcing. Fast feedbacks are changes of quantities such as atmospheric water vapor and clouds, which change as climate changes, thus amplifying or diminishing climate change. Fast feedbacks come into play as global temperature changes, so their full effect is delayed several centuries by the thermal inertia of the ocean, which slows full climate response. However, about half of the fast-feedback climate response is expected to occur within a few decades. Climate response time is one of the important 'details' that climate models help to elucidate.



Figure 1: Global temperature relative to peak Holocene temperature, based on ocean cores. (View PDF of figure)

We also show that slow feedbacks amplify the global response to a climate forcing. The principal slow feedback is the area of Earth covered by ice sheets. It is easy to see why this feedback amplifies the climate change, because reduction of ice sheet size due to warming exposes a darker surface, which absorbs more sunlight, thus causing more warming. However, it is difficult for us to say how long it will take ice sheets to respond to human-made climate forcing because there are no documented past changes of atmospheric CO2 nearly as rapid as the current human-made change.

Ice sheet response to climate change is a problem where satellite observations may help. Also ice sheets models, as they become more realistic and are tested against observed ice sheet changes, may aid our understanding. But first let us obtain broad guidance from climate changes in the 'recent' past: the Pliocene and Pleistocene, the past 5.3 million years.

Figure 1 shows global surface temperature for the past 5.3 million years as inferred from cores of ocean sediments taken all around the global ocean. The last 800,000 years are expanded in the lower half of the figure. Assumptions are required to estimate global surface temperature change from deep ocean changes, but we argue and present evidence that the ocean core record yields a better measure of global mean change than that provided by polar ice cores.

Civilization developed during the Holocene, the interglacial period of the past 10,000 years during which global temperature and sea level have been unusually stable. Figure 1 shows two prior interglacial periods that were warmer than the Holocene: the Eemian (about 130,000 years ago) and the Holsteinian (about 400,000 years ago). In both periods sea level reached heights at least 4-6 meters (13-20 feet) greater than today. In the early Pliocene global temperature was no more than 1-2°C warmer than today, yet sea level was 15-25 meters (50-80 feet) higher.

The paleoclimate record makes it clear that a target to keep human made global warming less than 2°C, as proposed in some international discussions, is not sufficient — it is a prescription for disaster. Assessment of the dangerous level of CO2, and the dangerous level of warming, is made difficult by the inertia of the climate system. The inertia, especially of the ocean and ice sheets, allows us to introduce powerful climate forcings such as atmospheric CO2 with only moderate initial response. But that inertia is not our friend — it means that we are building in changes for future generations that will be difficult, if not impossible, to avoid.



Figure 2: Greenland (a) and Antarctic (b) mass change deduced from gravitational field measurements by Velicogna (2009) and best-fits with 5-year and 10-year mass loss doubling times. (View PDF of figure)

One big uncertainty is how fast ice sheets can respond to warming. Our best assessment will probably be from precise measurements of changes of the mass of the Greenland and Antarctic ice sheets, which can be monitored via measurements of Earth's gravitational field by satellites.

Figure 2 shows that both Greenland and Antarctic ice sheets are now losing mass at significant rates, as much as a few hundred cubic kilometers per year. We suggest that mass loss from disintegrating ice sheets probably can be approximated better by exponential mass loss than by linear mass loss. If either ice sheet were to lose mass at a rate with doubling time of 10 years or less, multi-meter sea level rise would occur this century.

The available record (Fig. 2) is too brief to provide an indication of the shape of future ice mass loss, but the data will become extremely useful as the record lengthens. Continuation of these satellite measurements should have high priority.

A copy of this web page is also available as a PDF document.

References

Hansen, J.E., and Mki. Sato, 2011: Paleoclimate implications for human-made climate change. In Climate Change at the Eve of the Second Decade of the Century: Inferences from Paleoclimate and Regional Aspects: Proceedings of the Milutin Milankovitch 130th Anniversary Symposium. A. Berger, F. Mesinger, and D. Šijači, Eds. Springer, submitted.

Velicogna, I., 2009: Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE. Geophys. Res. Lett., 36, L19503, doi:10.1029/2009GL040222.

Andy
Non scolae sed vitae discimus

Posts : 215
Join date : 2011-04-11

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Wed Dec 07, 2011 8:06 am

J. E. Hansen is a remarkable man.

What's most remarkable about him is that he is shameless enough to show his face at all after having been as wrong as wrong can be over a period of three decades.

Here's what he predicted in the 1980s: his "worst case" scenario actually anticipated less CO2 in the atmosphere than we have now, so we should be cooking far above his red line:



His "best case" scenario anticipated zero increase in CO2 (thanks to his proposed gasoline taxes), but even his green line--anticipating no increase in CO2 since the mid-1980s--predicts warmer temperatures than we have now.

In other words, the increase in CO2 since the mid-1980s has been far worse than his "worst case," but the temperature situation is far cooler than his "best case."

We've been watching the CO2 shoot up dramatically--especially in the last 10-15 years--but we haven't seen a commensurate temperature increase (a fool might be tempted to suspect that maybe temperatures are determined by factors other than just CO2 scratch ).

Will there come a time when we stop listening to Hansen?

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  Andy on Wed Dec 07, 2011 8:15 am

I just knew that posting here would elucidate the matter quickly.
Thank, Pinz!

Andy
Non scolae sed vitae discimus

Posts : 215
Join date : 2011-04-11

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Wed Dec 07, 2011 8:19 am

That Hansen guy ...

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Wed Dec 07, 2011 8:30 am

If you look at the red box on the far right (which shows the last 12,000 years), you can see that our interglacial period has been the coolest one in the last 420,000 years (the hottest period in human history was that little red spike 3,000 years ago). That little blue spike at the farthest of the far right is our last 150 years of "global warming."

We are very lucky, but our brief warm spell is about over--prepare to put on your furs and long underwear.


pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Wed Dec 07, 2011 11:00 am

Ice and easy: Henry Raeburn's Skating Minister

Throughout December, Jonathan Jones is selecting his top wintry artworks. Here, he admires Henry Raeburn's Reverend Robert Walker Skating on Duddingston Loch, a picture of perfect control on the slippery ice.

Jonathan Jones

guardian.co.uk, Tuesday 6 December 2011 10.41 GMT



Winter is freedom in Henry Raeburn’s portrait of a minister in black hat, coat and stockings skating on Duddingston Loch in about 1795. The confident grace of the Reverend Robert Walker as he slides with perfect control across a slippery sheet of frozen water is infectious; he makes it look so easy. He is a hero of the Scottish Enlightenment, expressing through his wintry flight what economists and historians were achieving in the Edinburgh of his day: the triumph of reason. The mountains beyond look truly bleak and terrible. But the skating minister floats in joy, taking his rational exercise

Photographer: Scottish National Gallery/Scottish National Gallery

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Wed Dec 07, 2011 11:43 am

That's a reminder of the "little ice age." Temperatures have been rising since that time (which people were happy about, until recently).

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Thu Dec 08, 2011 3:37 am

The UAH global temperature anomaly for November seems to be late, so I'll post a different organization's readout instead this month--November 2011 was 0.09 degrees warmer than the 1981-2011 average for November:


pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Mon Dec 12, 2011 3:22 am

I know you are all upset that the UAH Global Temperature Anomaly update is late this month, as well you should be. bounce

I have the explanation, such as it is, from Dr. Spencer himself. I realize that this is far from satisfactory, but what can you do? Neutral

"There has been a delay in our monthly processing of global temperature data from AMSU.

An undersea telecommunications cable used to transmit about half of the huge volume of data coming from the Aqua satellite was cut in late November off the coast of the Netherlands, delaying receipt of that data. While there were redundant data transmission capabilities, apparently both failed.

Also, John Christy and I have been on separate travels quite a bit lately (I spent 2 weeks in Miami after my daughter had an emergency C-section — I’m a grandpa!) and now I’m at the AGU in San Francisco, with a trip to DC early next week, so monitoring of the situation has been difficult."

-- Dr. Roy Spencer

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Mon Dec 12, 2011 8:53 am

Global Approval For Roadmap To Climate Pact
Sky News


Global Approval For Roadmap To Climate Pact

The world's nations have agreed to push for a new climate treaty which would deliver a legally-binding global deal to cut emissions - but environmentalists say it does not go far enough.

The deal came after two-and-a-half days of round-the-clock wrangling among 194 nations in Durban, South Africa, under the UN Framework Convention on Climate Change (UNFCCC).

European Climate Commissioner Connie Hedegaard said the agreement marked the shift that had occurred over the last 20 years, when the world first set out to tackle climate change and tied only rich countries to carbon constraints.

"The BASIC countries took some significant new steps in acknowledging that the world of the 21st century is not the same as the 20th century," she said referring to the four big emerging economies - Brazil, South Africa, India and China.

UNFCCC chief Christiana Figueres cited the words of Nelson Mandela when she tweeted: "In honour of Mandela: It always seems impossible until it is done. And it is done."

The UK's Climate Change Secretary Chris Huhne hailed the deal as a "significant step forward".

He said it also it sent a strong signal to businesses and investors about moving to a low carbon economy.

But environmental groups said negotiators had failed to show the ambition necessary to cut emissions by levels that would limit global temperature rises to no more than 2C and avoid "dangerous" climate change.

Keith Allott, head of climate change at WWF-UK, said: "Governments have salvaged a path forward for negotiations, but we must be under no illusion - the outcome of Durban leaves us with the prospect of being legally bound to a world of 4C warming.

"This would be catastrophic for people and the natural world. Governments have spent crucial days focused on a handful of specific words in the negotiating text, but have paid little heed to repeated warnings from the scientific community that much stronger, urgent action is needed to cut emissions."

He welcomed the EU's role in a "high ambition coalition" of countries including the small island states and some of the poorest nations in the world, but urged Europe to show leadership by increasing its promise to cut emissions by 20% by 2020 to 30%.

The treaty will be negotiated by 2015 and coming into force from 2020.

Also agreed at the Durban talks was the establishment of a green climate fund to channel billions of pounds to poor countries to help them cope with impacts of global warming such as floods and drought - but no sources of money were found.

Rich countries have pledged \$100bn (£64bn) a year by 2020 for developing countries to deal with climate change and develop without polluting.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Mon Dec 12, 2011 8:35 pm

A question, Pinz.

Beattie & Geiger's "Frozen in Time" is an enthralling account of exhumation of bodies from Sir John Franklin's disastrous late 19th c expedition to find the North-West passage:



My question is: given the rate of calving of the Antarctic Ross Ice Shelf since 1912, is it possible that the bodies of Evans, Scott, Oates, Wilson and Bowers might be recovered?

The crucial difference between the two expeditions is that the Franklin remains were buried on land while the Scott party perished on the sea ice. Since Evans died first (i.e. furthest south) the recovery of his body would be most probable, I suppose.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Mon Dec 12, 2011 10:07 pm

It depends on whether the glacier is growing or shrinking.

If it's growing, it will flow faster and calve more, but if it's shrinking, it will stop calving and recede inland. The rate of melting will then determine his fate, and he might be found like Ötzi the alpine ice man.

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Mon Dec 12, 2011 10:43 pm

pinhedz wrote:he might be found like Ötzi the alpine ice man.

Yes, I'd considered posting this on the Otzi thread.

But the difference is that Otzi was discovered in the Austria-Italian Alps- i.e. on terra firma, like the Franklin expedition remains.

Scott and his men died on the Great Ice Barrier (aka the Ross Ice Shelf)- i.e. on floating sea ice.

[Actually, I can't remember whether Evans, the first fatality, made it down the Beardmore glacier and onto the sea ice. Someone will put me right on this.]

My question is about the rate of erosion of this sea ice. Would ice at the foot of the Beardmore glacier in 1912 have long since floated out to sea by 2011?

Another factor, of course, is that the northward drift of the polar party's bodies would have been impeded by Ross island (home to the volcanoes Erebus and Terror) on which Scott established his base at Mc Murdo Sound.



Last edited by eddie on Tue Dec 13, 2011 4:40 am; edited 1 time in total

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Tue Dec 13, 2011 4:35 am

This map makes things a bit clearer:



How much of the 1912 Ross Ice shelf (shaded area) still exists?

BTW- Evans does appear from the map to have died on terra firma.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Sat Dec 24, 2011 11:42 pm

According to this map from NASA, Scott Wilson Bowers and Oates have been moving several hundred meters per year toward the water line--faster as they get closer--so after 100 years they may have moved at least several 10s of kilometers.

It's difficult to tell from the color code and the scale of this map, but it seems very possible they may have been deposited in the sea by now.

The others are probably still in the ice.


pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Sat Dec 24, 2011 11:47 pm

Dr. Spencer has finally put out his November update.

Such a long wait to see there has been no change--we're still 12/100ths of a degree about the 1979-2011 average (evidently the temperature sensers are much more sensitive than my thermometer):


pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Sun Dec 25, 2011 1:10 am

^^

Thanks for the research, Pinz. Inconclusive, but interesting.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  Constance on Sun Dec 25, 2011 2:18 am

I'm not drawing any conclusion about climate change, but we've had a very unseasonably mild Oct, Nov and Dec. It's been just wonderful! I've been taking my dog for a walk every day. We go for about a mile, it takes me about an hour. Is that slow?

What's the weather been like where you are Pinz? I bet it's been mild, too.

Constance

Posts : 500
Join date : 2011-04-11
Age : 59
Location : New York City

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Sun Dec 25, 2011 4:18 pm

Brown Christmas in Minnesota, although it snowed the day before yesterday and there were a number of accidents due to last-minute shoppers racing around.

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  eddie on Sun Dec 25, 2011 10:39 pm


Steven Appleby.

eddie
The Gap Minder

Posts : 7840
Join date : 2011-04-11
Age : 60
Location : Desert Island

Back to top Go down

Re: The UNREAL climate change thread

Post  pinhedz on Fri Dec 30, 2011 12:42 pm

Watch out--your cell phone might not work this weekend:

http://www.news.com.au/technology/suns-flare-set-to-storm-the-airways/story-e6frfrnr-1226233080338

pinhedz
Schrödinger's Hepcat

Posts : 11532
Join date : 2011-04-11
Location : DC

http://www.balalaika.org/

Back to top Go down

Re: The UNREAL climate change thread

Post  Andy on Mon Jan 09, 2012 6:32 pm

Carbon emissions 'will defer Ice Age'
By Richard Black

Environment correspondent, BBC News

The climate, if not species, of an Ice Age "ought" to return within 1,500 years
Continue reading the main story
Related Stories
Climate 'grave' security threat
The moment Britain became an island
'Scary' climate message from past
Human emissions of carbon dioxide will defer the next Ice Age, say scientists.

The last Ice Age ended about 11,500 years ago, and when the next one should begin has not been entirely clear.

Researchers used data on the Earth's orbit and other things to find the historical warm interglacial period that looks most like the current one.

In the journal Nature Geoscience, they write that the next Ice Age would begin within 1,500 years - but emissions have been so high that it will not.

Continue reading the main story

Start Quote
I don't think it's realistic to think that we'll see the next glaciation on the [natural] timescale”
End Quote
Prof Lawrence Mysak

McGill University
"At current levels of CO2, even if emissions stopped now we'd probably have a long interglacial duration determined by whatever long-term processes could kick in and bring [atmospheric] CO2 down," said Luke Skinner from Cambridge University.

Dr Skinner's group - which also included scientists from University College London, the University of Florida and Norway's Bergen University - calculates that the atmospheric concentration of CO2 would have to fall below about 240 parts per million (ppm) before the glaciation could begin.

The current level is around 390ppm, and other research groups have shown that even if emissions were shut off instantly, concentrations would remain elevated for at least 1,000 years, with enough heat stored in the oceans potentially to cause significant melting of polar ice and sea level rise.

Orbital wobbles

The root causes of the transitions from Ice Age to interglacial and back again are the subtle variations in the Earth's orbit known as the Milankovitch cycles, after the Serbian scientist Milutin Milankovic who described the effect nearly 100 years ago.

The variations include the eccentricity of the Earth's orbit around the Sun, the degree to which its axis is inclined, and the slow rotation of its axis.


Glaciation and its reverse are related to cycles discovered by Milutin Milankovic These all take place on timescales of tens of thousands of years.

The precise way in which they change the climate of the Earth from warm interglacial to cold Ice Age and back every 100,000 years or so is not known.

On their own, they are not enough to cause the global temperature difference of about 10C between Ice Age and interglacial. The initial small changes are amplified by various factors including the release of carbon dioxide into the atmosphere as warming begins, and absorption of the gas by the oceans as the ice re-forms.

It is also clear that each transition is different from previous ones, because the precise combination of orbital factors does not repeat exactly - though very similar conditions come around every 400,000 years.

The differences from one cycle to the next are thought to be the reason why interglacial periods are not all the same length.

Using analysis of orbital data as well as samples from rock cores drilled in the ocean floor, Dr Skinner's team identified an episode called Marine Isotope Stage 19c (or MIS19c), dating from about 780,000 years ago, as the one most closely resembling the present.

The transition to the Ice Age was signalled, they believe, by a period when cooling and warming seesawed between the northern and southern hemispheres, triggered by disruptions to the global circulation of ocean currents.

If the analogy to MIS19c holds up, this transition ought to begin within 1,500 years, the researchers say, if CO2 concentrations were at "natural" levels.

As things stand, they believe, it will not.

Loving CO2

The broad conclusions of the team were endorsed by Lawrence Mysak, emeritus professor of atmospheric and oceanic sciences at McGill University in Montreal, Canada, who has also investigated the transitions between Ice Ages and warm interglacials.

Continue reading the main story Climate change glossary
Select a term to learn more:
Adaptation AdaptationAnnex I countriesAnnex II countriesAnthropogenic climate changeAosisAR4Atmospheric aerosolsBali action planBali roadmapBaseline for cutsBiofuelBlack carbonBoxer-Kerry billBusiness as usualCap and tradeCarbon capture and storage (CCS)Carbon dioxide (CO2)Carbon dioxide (CO2) equivalentCarbon footprintCarbon intensityCarbon leakageCarbon neutralCarbon offsettingCarbon sequestrationCarbon sinkCertified Emission Reduction (CER)Clean Coal TechnologyClean Development Mechanism (CDM)Climate changeCFCCO2Commitment periodCOP15Country in transitionDangerous climate changeDeforestationEmission Trading Scheme (ETS)EU Burden-sharing agreementFeedback loopFlexible mechanismFossil_fuelsG77Geological sequestrationGlobal average temperatureGlobal energy budgetGlobal dimmingGlobal warmingGlobal Warming Potential (GWP)Green Climate FundGreenhouse gases (GHGs)Greenhouse effectHockey stickIPCCJoint implementationKyoto ProtocolLDCsLULUCFMajor Economies Forum on Energy and ClimateMethaneMitigationMonitoring, Reporting and Verification (MRV)Nairobi work programNatural greenhouse effectNon-annex I countriesOcean acidificationppm (350/450)Per-capita emissionsPre-industrial levels of carbon dioxideREDDRenewable energyStern reviewTechnology transferTipping pointTwenty-twenty-twenty (20-20-20)UNFCCCWaxman-Markey energy billWeather
Adaptation
Action that helps cope with the effects of climate change - for example construction of barriers to protect against rising sea levels, or conversion to crops capable of surviving high temperatures and drought.
Glossary in full "The key thing is they're looking about 800,000 years back, and that's twice the 400,000-year cycle, so they're looking at the right period in terms of what could happen in the absence of anthropogenic forcing," he told BBC News.

He suggested that the value of 240ppm CO2 needed to trigger the next glaciation might however be too low - other studies suggested the value could be 20 or even 30ppm higher.

"But in any case, the problem is how do we get down to 240, 250, or whatever it is? Absorption by the oceans takes thousands or tens of thousands of years - so I don't think it's realistic to think that we'll see the next glaciation on the [natural] timescale," Prof Mysak explained.

Groups opposed to limiting greenhouse gas emissions are already citing the study as a reason for embracing humankind's CO2 emissions.

The UK lobby group the Global Warming Policy Foundation, for example, has flagged up a 1999 essay by astronomers Sir Fred Hoyle and Chandra Wickramasinghe, who argued that: "The renewal of ice-age conditions would render a large fraction of the world's major food-growing areas inoperable, and so would inevitably lead to the extinction of most of the present human population.

"We must look to a sustained greenhouse effect to maintain the present advantageous world climate. This implies the ability to inject effective greenhouse gases into the atmosphere, the opposite of what environmentalists are erroneously advocating."

Luke Skinner said his group had anticipated this kind of reception.

"It's an interesting philosophical discussion - 'would we better off in a warm [interglacial-type] world rather than a glaciation?' and probably we would," he said.

"But it's missing the point, because where we're going is not maintaining our currently warm climate but heating it much further, and adding CO2 to a warm climate is very different from adding it to a cold climate.

"The rate of change with CO2 is basically unprecedented, and there are huge consequences if we can't cope with that."

Source: BBC news-site

Andy
Non scolae sed vitae discimus

Posts : 215
Join date : 2011-04-11

Back to top Go down

Re: The UNREAL climate change thread

Post  Sponsored content Today at 4:16 am


Sponsored content


Back to top Go down

Page 2 of 25 Previous  1, 2, 3 ... 13 ... 25  Next

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum