Climate conditions in 2050 crucial to avoid harmful impacts in 2100

Jan 11, 2010
Scientists are unraveling a chain of events that led to large-scale warmings and coolings across the Northern Hemisphere during past ice ages. As ice sheets expanded, water levels dropped in the narrow Bering Strait (left) and cut off the flow of relatively fresh water from the northern Pacific through the Arctic into the saltier Atlantic. This altered ocean currents, increasing the flow of Atlantic water northward from the tropics and producing warming in the north Atlantic (right, shown in dark red) that melted ice sheets and affected climate patterns and sea levels across much of the world. Credit: Courtesy Nature, modified by UCAR

While governments around the world continue to explore strategies for reducing greenhouse gas emissions, a new study suggests policymakers should focus on what needs to be achieved in the next 40 years in order to keep long-term options viable for avoiding dangerous levels of warming.

The study is the first of its kind to use a detailed energy system model to analyze the relationship between mid-century targets and the likelihood of achieving long-term outcomes.

"Setting mid-century targets can help preserve long-term policy options while managing the risks and costs that come with long-term goals," says co-lead author Brian O'Neill, a scientist at the National Center for Atmospheric Research (NCAR).

The study, conducted with co-authors at the International Institute for Applied Systems Analysis (IIASA) in Austria and the Energy Research Centre of the Netherlands, is being published today in the . It was funded by IIASA, a European Young Investigator Award to O'Neill, and the National Science Foundation, NCAR's sponsor.

The researchers used a computer simulation known as an integrated assessment model to represent interactions between the energy sector and the climate system. They began with "business as usual" scenarios, developed for the Intergovernmental Panel on Climate Change's 2000 report, that project future in the absence of climate policy. They then analyzed the implications of restricting emissions in 2050, using a range of levels.

The team focused on how emissions levels in 2050 would affect the feasibility of meeting end-of-century temperature targets of either 2 or 3 degrees Celsius (about 3.5 degrees or 5.5 degrees Fahrenheit, respectively) above the pre-industrial average.

Mid-century thresholds

The study identifies critical mid-century thresholds that, if surpassed, would make particular long-term goals unachievable with current energy technologies.

For example, the scientists examined what would need to be done by 2050 in order to preserve the possibility of better-than-even odds of meeting the end-of-century temperature target of 2 degrees Celsius of warming advocated by many governments.

One "business as usual" scenario showed that global emissions would need to be reduced by about 20 percent below 2000 levels by mid-century to preserve the option of hitting the target. In a second case, in which demand for energy and land grow more rapidly, the reductions by 2050 would need to be much steeper: 50 percent. The researchers concluded that achieving such reductions is barely feasible with known energy sources.

"Our simulations show that in some cases, even if we do everything possible to reduce emissions between now and 2050, we'd only have even odds of hitting the 2 degree target-and then only if we also did everything possible over the second half of the century too," says co-author and IIASA scientist Keywan Riahi.

The research team made a number of assumptions about the energy sector, such as how quickly the world could switch to low- or zero-carbon sources to achieve emission targets. Only current technologies that have proven themselves at least in the demonstration stage, such as nuclear fission, biomass, wind power, and carbon capture and storage, were considered. Geoengineering, nuclear fusion, and other technologies that have not been demonstrated as viable ways to produce energy or reduce emissions were excluded from the study.

The 2-degree goal

Research shows that average global temperatures have warmed by close to 1 degree C (almost 1.8 degrees F) since the pre-industrial era. Much of the warming is due to increased emissions of greenhouse gases, predominantly carbon dioxide, due to human activities. Many governments have advocated limiting global temperature to no more than 1 additional degree Celsius in order to avoid more serious effects of climate change.

During the recent international negotiations in Copenhagen, many nations recognized the case for limiting long-term warming to 2 degrees Celsius above pre-industrial levels, but they did not agree to a mid-century emissions target.

"Even if you agree on a long-term goal, without limiting emissions sufficiently over the next several decades, you may find you're unable to achieve it. There's a risk that potentially desirable options will no longer be technologically feasible, or will be prohibitively expensive to achieve," O'Neill says.

On the other hand, "Our research suggests that, provided we adopt an effective long-term strategy, our emissions can be higher in 2050 than some proposals have advocated while still holding to 2 degrees Celsius in the long run," he adds.

Cautions

The researchers caution that this is just one study looking at the technological feasibility of mid- and end-of-century emissions targets. O'Neill says that more feasibility studies should be undertaken to start "bounding the problem" of emissions mitigation.

"We need to know whether our current and planned actions for the coming decades will produce long-term climate change we can live with," he says. "Mid-century targets are a good way to do that."

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Provided by National Center for Atmospheric Research

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steveig
2.8 / 5 (11) Jan 11, 2010
"Scientists are unraveling a chain of events that led to large-scale warmings and coolings across the Northern Hemisphere during past ice ages."

"The researchers used a computer simulation known as an integrated assessment model to represent interactions between the energy sector and the climate system."

I am a layman, but how could a study that focusses on past ice ages be considered reliable when the industrial age has only been going forward during the past century. There was no anthropological CO2 emissions back then!!! Just another credible piece of research tht conforms to the government's criteria for funding. And let's not forget the research gem - further studies need to be conducted...
Sanescience
2.8 / 5 (8) Jan 11, 2010
Climate change science is all conjecture. Code used to simulate the earths climate is INCREDIBLY simplified and contains giant holes where we have no idea how things work. *PLUS* in the rare event that code is made available to the open community, errors in coding are found that can skew the results regardless of how good your program represents actual weather behavior.

We need to organize a MASSIVE effort to get these computer programs up to snuff and provide the computational resources necessary to use them. Assuming, of course, this is the most important, immediate crisis facing man kind.
GrayMouser
1.9 / 5 (7) Jan 11, 2010
We need to organize a MASSIVE effort to get these computer programs up to snuff and provide the computational resources necessary to use them. Assuming, of course, this is the most important, immediate crisis facing man kind.

According to AlGo the science is settled. If so we don't need a enormous Manhattan Project style project to build faster and bigger computers.

On the other hand, if you believe the problem is intractable with what we know and have available, there is no reason to fund such a boondoggle.
StarDust21
5 / 5 (2) Jan 12, 2010
100 years ahead seems to me a far too long time to get accurate predictions based on current models.
Parsec
2.6 / 5 (5) Jan 12, 2010
I do believe that global warming is real and man caused CO2 emissions are at the heart of it. Having said that, it is also true that 100 years ahead is way too far to get an accurate prediction based on current models.

However, CO2 levels are risen and fallen in past times way above what we see today. Estimated levels in the middle Eocene( about 55 million years ago) is greater than 1000ppm (todays is about 390ppm and growing about 2% per year). No one has suggested that man is the only source of CO2, just that when the CO2 levels rise the temperature goes way up. During the middle Eocene global temperatures were also MUCH warmer. No matter what you may think of the proxies used, the error bars (95%) for the CO2 are less than 100ppm, and the temperature less than 10 deg F. There is no conceivable solar radiation source capable of raising the temp that much. Volcano's emit CO2.
Parsec
5 / 5 (5) Jan 12, 2010
Also, computers need to get (and will get) more powerful for a variety of reasons having nothing to do with climate change calculations. In days of trillion dollar budgets, a few hundred million for better computers does not equate to massive spending or a boondoogle. We need better computers just to better calculate airflow in cars and airplanes, play 3D games, astronomy and chemistry simulations, etc.
Bob_Kob
1 / 5 (2) Jan 12, 2010
We must prepare for 2200!
Claudius
2.3 / 5 (9) Jan 12, 2010
Much of the warming is due to increased emissions of greenhouse gases, predominantly carbon dioxide, due to human activities.


This assumption has been falsified over and over again by the fact that a) carbon dioxide is an insignificant greenhouse gas, water vapor being the most significant at 95% of the effect. b) There is no evidence that human activities have in any way influenced the temperature.

Unless, of course, you rely on data provided by the CRU and IPCC, which we now know to have been fiddled with.
Sciencebee
1.7 / 5 (6) Jan 12, 2010
No one is going to do anything about this. People in large groups only change when they are forced. Making changes now will cost people money. People like their money and face it, they will be dead before all this happens so they don't care. Hear and now. They. don't. care. That is really all there is to say. Personally I think it is totally amazing. To me it doesn't matter if the science is correct or incorrect. If true we are talking about global catastrophe worthy of any and all preventive measures.
DozerIAm
2.3 / 5 (3) Jan 12, 2010
In days of trillion dollar budgets, a few hundred million for better computers does not equate to massive spending or a boondoogle. We need better computers just to better calculate airflow in cars and airplanes, play 3D games, astronomy and chemistry simulations, etc.

Thinking like that is why we have trillion dollar budgets - everyone has their pet projects and to heck with responsible spending. But "increase federal spending" is another way of saying "tax people more", and I say, if it interests you that much spends your own money on it but keep your hand out of my wallet!!! Anyway, better computers will come as a natural part of the market's "buy, use, upgrade" process. We don't need the government to get involved unless we want that process to get wrecked. Example: which is less frustrating and less complicated, going to the DMV/RMV to get a vehicle registered or going to a computer store to buy a new external hard drive?
DozerIAm
3.7 / 5 (6) Jan 12, 2010
To me it doesn't matter if the science is correct or incorrect.


That is a beautiful example of the AWG proponents' mindset. Thank you for sharing it with us. By that "logic" we should build and launch a huge and expensive space fleet to protect us from a potential alien invasion because someone somewhere probably warned us about that and after all, "If true we are talking about global catastrophe worthy of any and all preventive measures."

3432682
2.7 / 5 (7) Jan 12, 2010
The sky is falling - Not. All the predictions are proving wrong. Keep all research funding modest, and stop funding giant power plants like solar, which are nowhere near cost-competitive with fossil fuel. Reduce the absurd regulatory cost of nuclear power, cut in by 2/3, and build lots of nuke plants. Make nuke plants modular, a commodity.
defunctdiety
2.1 / 5 (7) Jan 12, 2010
I am a layman, but how could a study that focusses on past ice ages be considered reliable when the industrial age has only been going forward during the past century.

This is really the only thing that needed to be said about this article.

We have (far) less than 100 years worth of relevant data with which they are wanting to extrapolate to 100 year spans. This is bad science. This "study" is a farce and it's "findings" meaningless towards what they would like to say.
I do believe that global warming is... man caused...

What scientific evidence does this belief spring from, Parsec? And please note, I said evidence, not correlation.
jonnyboy
1.6 / 5 (7) Jan 12, 2010
It just seems odd to me that they are using as their "business as usual" scenario the IPCC reports, which are the most political and least scientific of all the possible models in existence.
spdg
3 / 5 (4) Jan 12, 2010
I do believe that global warming is... man caused...

What scientific evidence does this belief spring from, Parsec? And please note, I said evidence, not correlation.


So you admit humans are increasing CO2, and CO2 does trap heat, therefore mathematically it is proven. The correlation is that it has in fact gotten warmer but you did say not to mention correlation.

Climate is likely affected by human activities, maybe enough to make life miserable in a hundred years. Climate is also affected by longer natural cycles capable of mass extinction. If Humans released all the fossilized CO2, they'd only return the earth to its original primordial state, but of course only plant-like life could exist there.
Sanescience
2.3 / 5 (3) Jan 12, 2010
So you admit humans are increasing CO2, and CO2 does trap heat, therefore mathematically it is proven. The correlation is that it has in fact gotten warmer but you did say not to mention correlation.


Ouch, that was painful to read.

There is no math or proof in that statement, only conjecture. The numbers have been played with so much it isn't even clear which comes first, the warming or the CO2.

There needs to be funding and an effort to,

A: Have three separate groups generate data sets where each method of collection is cited and the adjustments made to the numbers is cited and their standard error range is cited.

B: Organize 3 different groups to develop open source code projects that performs the analysis of the data.

C: Do not identify who worked on which parts and let all the scientific community choose which two predictions represent the likely case for global weather change and what humans can do about it.

But why do this? It's only the fate of the planet!
Claudius
2.3 / 5 (6) Jan 12, 2010
So you admit humans are increasing CO2


Well, in a sense, humans ARE increasing CO2. As are all the other animals on the planet. Living things prosper with warmer temperatures, and when there are more animals, the extra CO2 they produce increases atmospheric CO2. That is why CO2 levels lag behind temperature increases, which are driven by solar activity.

The amount produced by human industry, in contrast, is minuscule. Even so, CO2 is a far less significant greenhouse gas than water vapor. We just aren't having that much of an effect on temperatures.

This article is just more political bunk, and totally unscientific.
GrayMouser
1.8 / 5 (5) Jan 12, 2010
I do believe that global warming is real and man caused CO2 emissions are at the heart of it. Having said that, it is also true that 100 years ahead is way too far to get an accurate prediction based on current models.

First thing, as has been pointed out in other posting, the Greenhouse Effect has been proven false. The warming in a greenhouse is not due to trapped IR. Once you understand that, the entire concept of "Greenhouse Gases" is illogical. Thermodynamics don't work that way.
Read the paper titled "FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE
EFFECTS WITHIN THE FRAME OF PHYSICS". Try looking on
http://arxiv.org/...61v4.pdf
toyo
3 / 5 (4) Jan 18, 2010
I quote from the article:
"Much of the warming is due to increased emissions of greenhouse gases, predominantly carbon dioxide, due to human activities."

And so, by sheer repetition, the lie becomes a 'fact'.

Next time you see this sort of statement in an article, simply ignore the article itself.
It is an indication of the author's unquestioning faith, a measure of his unscientific, head-nodding agreement with unproven speculation, and a measure of the quality of unbiased research that author is capable of.