Will scientists ever agree on Global Warming?

Answer 1

They already do. Now they are trying to figure out how long it will last.

From RealClimate.org:

15 Mar 2005
How long will global warming last?
Filed under:
Climate Science

Paleoclimate

Greenhouse gases
— group @ 10:19 am - ()
Guest commentary from David Archer (U. Chicago)

The notion is pervasive in the popular and scientific literature that the lifetime of anthropogenic CO2 released to the atmosphere is some fuzzy number measured most conveniently in decades or centuries. The reality is that the CO2 from a gallon out of every tank of gas will continue to affect climate for tens and even hundreds of thousands of years into the future.


The U.S. Environmental Protection Agency Inventory of U.S. Greenhouse Gas Emissions and Sinks (2005) has the CO2 lifetime listed as 5-200 years, for example [1]. I have seen "hundreds of years" in scientific manuscripts and in environmentalist literature. David Goodstein in his excellent book The End of the Age of Oil states, "If we were to suddenly stop burning fossil fuel, the natural carbon cycle would probably restore the previous concentration in a thousand years or so." I assume that Goodstein is conservatively applying several century-long e-folding times to derive his thousand years, but he implicitly assumes that the CO2 will relax toward its 1750 concentration. The point is that it does not.

When you release a slug of new CO2 into the atmosphere, dissolution in the ocean gets rid of about three quarters of it, more or less, depending on how much is released. The rest has to await neutralization by reaction with CaCO3 or igneous rocks on land and in the ocean [2-6]. These rock reactions also restore the pH of the ocean from the CO2 acid spike. My model indicates that about 7% of carbon released today will still be in the atmosphere in 100,000 years [7]. I calculate a mean lifetime, from the sum of all the processes, of about 30,000 years. That's a deceptive number, because it is so strongly influenced by the immense longevity of that long tail. If one is forced to simplify reality into a single number for popular discussion, several hundred years is a sensible number to choose, because it tells three-quarters of the story, and the part of the story which applies to our own lifetimes.

However, the long tail is a lot of baby to throw out in the name of bath-time simplicity. Major ice sheets, in particular in Greenland [8], ocean methane clathrate deposits [9], and future evolution of glacial/interglacial cycles [10] might be affected by that long tail. A better shorthand for public discussion might be that CO2 sticks around for hundreds of years, plus 25% that sticks around forever.

The sticking-around-forever idea is not new, and the picture has not changed by very much since the effect was first predicted back in 1992 [2]. You can estimate the magnitude of the effect pretty well just using CO2 thermodynamics and the back of an envelope. It could be argued (by someone with a cruel heart) that since we don’t understand why CO2 was lower during the last ice age, we ought not go around making forecasts for the future. Well, OK, but I would point out that CO2 in the past appears to act as an amplifier for orbitally forced climate change, so if anything, we might expect the carbon cycle in the future to amplify our own climate forcing, rather than counteract it. If the past is any guide, CO2 surprises in the future, in the long run, seem unlikely to help us out.

A long lifetime for CO2 adjustment is also consistent with an isotopic event in the deep sea sedimentary record from 55 million years ago, the Paleocene/Eocene Thermal Maximum event. The record tells the story of the sudden release of an isotopically light source of carbon, triggering a fast warming in the deep sea of about 5 degrees C. Both the carbon isotope signal and the temperature (inferred from oxygen isotopes) then relaxed back toward their initial values in about 100,000 years. If the released carbon were initially in the form of methane, it would have been oxidized to CO2 within a few decades, but as CO2 it apparently stuck around, warming the deep ocean, for a long time before it went away.

The shortest lifetime estimates, such as EPA’s 5-years, derive from the exchange flux of CO2 between the atmosphere and ocean, which is about 200 Gt C/year (1 Gt C is 1012 kg of carbon) in each direction. Because the exchange flux is back-and-forth, it has nothing to do with the net uptake by the ocean of new CO2 to the system, which relies on the imbalance between the upward and downward exchange fluxes. That imbalance is only about 2 Gt C/year.

Even the present-day net flux tends to underestimate the real lifetime of global warming. The atmosphere contains about 160 Gt more carbon than it did then. If we divide this number by the CO2 invasion flux into the ocean of 2 Gt C/year, we get an apparent uptake time scale of 80 years. This result is shorter than model air/water equilibration time scales by a factor of four or so. I believe the problem is with the simple calculation. The CO2 concentration of the atmosphere is going up continuously, and so it invades the ocean as it equilibrates with warm surface waters. If atmospheric CO2 were not going up, the warm surface waters would saturate in a year or two, the overall ocean invasion rate would decrease, and the lifetime estimates by this method would increase. Different parts of the ocean equilibrate with the atmosphere on different time scales, ranging from a year for the tropical surface ocean to a millennium for the deep sea. Overall, model experiments show a CO2 equilibration time of a few centuries [5, 6, 11, 12]. The other problem with both of these conceptions is that they implicitly assure us that the CO2 concentration is going back to its initial concentration, which it will not.

Another source of short-lifetime bias in the community probably comes from a calculation used to compare the greenhouse consequences of different gases, called the Global Warming Potential (GWP) [13]. Some trace gases such as methane have a stronger impact on the heat balance of the earth, per molecule, than CO2 does. However, to really compare them fairly one might want to factor in the fact that methane only lives about 10 years before it goes away (actually, it is oxidized to CO2, another greenhouse gas, but it is common to ignore that in GWP calculatons). Global warming potentials are calculated by integrating the radiative energy impact of a molecule of gas over its atmospheric lifetime. However, if the full lifetime of CO2 were considered, including that long tail, then methane would be by that calculation unimportant. On human time scales, methane is certainly an important greenhouse gas, and so what's done is to arbitrarily limit the time horizon of the calculation to something like human timescales. Methane GWP is higher when considered on the 50-year time horizon than it is on the 500-year time horizon or it would be on a 500,000-year time horizon, if anyone bothered to do that calculation. Perhaps the adoption of time horizons for GWP calculations conditions scientists to believe that CO2 only persists for as long as this time horizon lasts. The table in the EPA document, for example, was associated with a discussion of global warming potentials.

It could also be that we-who-only-live-to-be-77.2-years-old don't want to worry about climate impacts from fossil fuel CO2 release 100,000 or even 1,000 years from now. That would be a perfectly rational position, and I have no argument with it. Climate change negotiations are grounded in IPCC projections and scenarios to the year 2100, a far cry from the year 100,000, but even 2100 seems almost unimaginably remote given the pace of social and technological change in the world today. On the other hand, nuclear waste lasts for millions of years for some isotopes such as iodine 129. The public seems to find this information relevant, so the true longevity of anthropogenic climate change might be considered by some to be relevant to here-and-now decisions as well. At any rate, the facts as reported ought to be accurate, rather than judging in advance that no one cares about climate impacts that last thousands of years and more into the future.

(with the subscript "No single lifetime can be defined for CO2 because of the different rates of uptake by different removal processes") (EPA (2005), Inventory of U.S. Greenhouse Gas Emissions and Sinks Draft Report: 1990 -2003, U.S. Environmental Protection Agency, Office of Atmospheric Programs
Walker, J.C.G. and J.F. Kasting, Effects of fuel and forest conservation on future
levels of atmospheric carbon dioxide. Palaeogeography, Palaeoclimatology, Palaeoecology (Global and Planetary Change Section), 1992. 97, 151-189.
Joos, F., et al., An efficient and accurate representation of complex oceanic and biospheric models of anthropogenic carbon uptake. Tellus, Ser. B, 1996. 48: p. 397-416.
Jain, A.K., et al., Distribution of radiocarbon as a test of global carbon cycle models. Global Biogeochem. Cycles, 1995. 9: p. 153-166.
Archer, D., H. Kheshgi, and E. Maier-Riemer, Multiple timescales for neutralization of fossil fuel CO2. Geophys. Res. Letters, 1997. 24: p. 405-408.
Archer, D., H. Kheshgi, and E. Maier-Reimer, Dynamics of fossil fuel CO2 neutralization by marine CaCO3. Global Biogeochem. Cycles, 1998. 12: p. 259-276.
Archer, D., Fate of fossil-fuel CO2 in geologic time. J. Geophys. Res. Oceans, in press.
Huybrechts, P. and J. De Wolde, The dynamic response of the Greenland and Antarctic ice sheets to multiple-centure climatic warming. J. Climate, 1999. 12: p. 2169-2188.
Archer, D.E. and B. Buffett, Time-dependent response of the global ocean clathrate reservoir to climatic and anthropogenic forcing. Geochem., Geophys., Geosys., 2005. 6(3): p. doi: 10.1029/2004GC000854.
Archer, D. and A. Ganapolski, A movable trigger: Fossil fuel CO2 and the onset of the next glaciation. Geochem., Geophys., Geosys., in press.
Sarmiento, J.L., U. Siegenthaler, and J.C. Orr, A perturbation simulation of CO2 uptake in an ocean general circulation model. J. Geophys. Res., 1992. 97: p. 3621-3645.
Sarmiento, J.L. and C.L. Quéré, Oceanic carbon dioxide uptake in a model of century-scale global warming. Science, 1996. 274: p. 1346-1350.
Jain, A.K., et al., Radiative forcings and global warming potentials of 39 greenhouse gases. J. Geophysical Res., 2000. 105(D16): p. 20,773-20,790.

Answer 2

No. Read "State of Fear" by Micheal Crighton and get the OTHER side, instead of just the side presented by the media. As to the comment that the ones paid by Energy Companies they have to get funding from SOMEONE. The science still PROVES it isn't being induced by man. Yeah that's the SCIENCE that isn't the FUNDING. Sure energy companies want that answer BUT they want to know if it is soley from man so they can hide that evidence while they change. They need the evidence to be HONEST. The fact is that the Earth naturally heats and cools. It has been doing this since the beginning of time and it will do it until the end of man's time. The last Ice Age ended in the '70's. Up until then they were talking about how man was causing the Earth to FREEZE. Now we are causing it to overheat. SURE!!! Try learing the REAL truth.

Answer 3

From what I know they all agree with Global Warming.
If I well remember, in 1992 had a World Convention in Rio de Janeiro,(ECO something...sorry I don't remember names well, but facts) where the most industrialized countries in the world, went to discuss about the effects of Industries in the nature. At that time, the most renowned scientists and nation's leaders in the world, agreed about the bed sides effects that industrialization has brought to the Nature, and promised to do something about it.
The destruction of the earth's ozone layer, was one of the main topics of the Convention.
Scientist alerted at that time, in 10 years the world would pass by a climate transformation, caused by the over warm of the earth, because the sun's rays would be passing directly to the earth, the sun's ray, would melt the ice in Alaska (the industrialization brought to there after Alaska becomes under US control is one of the reasons too) and over heat the water,in the rest of the world, that after its condensates becomes clouds that after getting heavy its transform in rains, that will cause catastrophes related to Climate.
Looks like, I can be wrong, they (leaders) didn't sign any treaty, but have ensured the world to take precautions, and preventives matters to help the planet from a slow destruction.

Answer 4

Scientists DO agree on this one! Politicians seem to be the ones not getting it. There IS global warming. Check out "An Inconvenient Truth' at theaters now. Quite enlightening and a bit depressing (with a glimmer of hope)!

Answer 5

I love how people complain about others disregarding the true facts and then quote "An Inconvenient Truth". When was the last time cold hard facts about an issue were presented in a movie theater?

Answer 6

Except for the ones paid by energy companies, they agree now.

Answer 7

sorry I don't understand what u mean by this *sorry* I know global warming...but what agreement b/w scientists???

Answer 8

They'll agree when it's too late for it to make a difference.

Answer 9

Nooooooooo..... Its in their own best intrest and advantage NOT to!!! 100k to 250k per year.... Are you kidding?????? That cow is gonna be milked till she drops!!!!

Answer 10

When politicians have enough money to pay them all off.

Answer 11

this is an Environmentalist version
and many will not agree with this
but some things cannot be denied
and just to waste space some solutions to ponder over

global warming is one of the Mega threats that loom over humanity,with many related factors each as mega as the other

in North Africa,India,Mexico ,millions of people are effected by land loss and desertification

In the days of the dinosaurs this planet was under an aquiferus manta ,a mist that covered the entire earth ,and there were no desserts .
Count how many there are today,and all of them are as a result of mans actions.
the sahara used to be forrests,it is now a dessert that grows by 7kilometres per year
arabia ,irak ,iran used to be fertile lands in biblical times
Ghengas Kahn put every thing to the sword and torch turning vast territories into desserts,and to make sure he filled all the wells with sand.

in recent times thousands of people have died because of exessive heat,usually old people.in India ,Mexico and France,
Deforestation causing desertification,the desert conditions causing very cold nights and scorching hot days

in china, thousands of what used to be farmers are running for their lives from the dust storms that have burried about 900 of their towns,and villages, transforming their lands into dessert,
and instead of producing food they are now needing it from some where else,

the Chinese will drastically effect the world food prices when they start buying water in the form of grains(1 ton of corn represents 1000 tons of water) ,at any cost destabalising governments, in some countries ,could be the result
(are you seeing more Chinese around interested in buying agricultural lands??? ,we do here in Mexico)

so as far as the food production is concerned Global warming or some of its effects are serious,

each degree rise in temperature means 10%crop loss

more landloss because of desertification every year,we have less areble land to produce food ,for an extra 70 million people ,and there is less and less water (because of deforestation),they areoverpumping deep carbon aquifiers to irrigate this production ,
and plowing more and more unstable lands ,because they have lost so many million hectares to desertification ,
because of bad farming practises ,such as using fertilizers and heavy machinary or over grazing.
(Ghengas would have been envious of the effects of modern Agriculture)

and there are less and less farmers to do it..because so many of their sons are leaving for the cities

Our consumption of water is ever increasing and our drinkable water supply is shrinking because of polution ,and the production of potable water is less all the time because of deforestation.
we are living in a bubble economy and when the bubble bursts
food prices will sky rocket,and so will the price of water.

the wars of the future will be for water and we will be up to our ears in the wrong water

RISING SEAS result in more landloss
The northpole is melting ,and we will know it without ice in our life times.
this does not affect the sea level because it is ice that is already in the water.but the melting ice from Green land and the south pole ,are another matter.

Global warming is in theory reversable,but it will mean global co operation between all countries ,and taking into account human nature and the world politics ,it is unlikely that this will happen,

At least not untill we are all in the middle of planetary disastres and it becomes a battle for the survival of humanity every where.

However
Almost all governments in the first world and many others who deal with them,are already working on this for a long time ,
In Mexico many farmers are being persuaded Agro forestall farming which includes trees ,like shade grown coffee

and many countries like Germany and the USA ,for example have made heavy commitments to reduce carbon emissions
Countries like Australia ,Denmark,USA and South Africa to name but a few are spending a lot on alternative energies ,

but all of this is still far to slow
greed to further exploit the petrolium business prevents fast positive advancement

SOLUTIONS
if you want to help the planet ,plant a tree every week ,if EVERYONE on the planet did this, we would be able to reverse the destructive processes,and start creating more biomass again.

reduce carbon emisions,and they are already working on that by alternative forms of energy and regulations on carbon producing materials,aerosol cans,burning rubbish,industrial chimneys,powerplants etc.

the world bank pays large subsidies for reforrestation to capture carbon and the best tree for this is the Pawlonia

Waterharvesting projects ,such as millions of small dams.to redirect over ground waterflows from the rains into the ground to supply subteranian water supplies.

the protection of existing forrests.and the production of water

stop building more highways,urban planning to include vegetation stop building cities encourage people to return to the land to conduct their business from there which now has become possible thanks to the internet.

education to motivate people to auto sufficiency by building more home food gardens.

education on environmental awareness
education on family planning to curb over´population

Agricultural education and improvements to follow the principals or sustainability and soil management.

more land design to prevent bush fires,such as--fire breaks

regulations and control for public behaviour

alternative effeciant public transport to discourage the use of the internal conbustion engine

recicling wastes,limit water use

i am a Permaculture Consultant for the department of Ecology for the regional government in Guerrero Mexico