Climate change is here — and worse than we thought

[LocoAko]

Read the article. It's in there, I promise.

I read it and missed the 5 words that clarified this. My apologies... lol.

[WeatherRusty]

To predict the behavior of ordinary people in advance, you only have to assume that they will always try to escape a disagreeable situation with the smallest possible expenditure of intelligence. The nice thing about reality is, when you don't believe in it, doesn't go away. Thinking something and wanting something makes it neither real or true when it comes to AGW denialism. The sad thing is nothing will ever become real for sceptics until it is experienced or learned. We all know learning isn't their strong suit and evidentally experiencing is a painfully slow process.

I love that statement.

The principle of cosmic laziness in action.

Nature will always take the shortest route and longest period of time in expending the least possible energy over an interval.

Sorry, I couldn't resist!

[donsutherland1]

When is the paper due out?

Monday.

[ben4vols]

Scientists such as Mann and Hansen are demonized precisely because they represent the public face of the enemy. In skeptic circles they are treated like Hitler and Stalin, to be despised as the head of a pernicious evil. Those guys must have huge cojones to not just walk away from it all.

My daughter gave me two grandkids and they are wonderful. Enjoy!

Those guys get paid handsomely to do what they do. They aren't walking away, they enjoy the attention which only helps build upon their delusions. Too bad they don't have the cajones to come out and debate their ideas.

[rygar]

Scientists such as Mann and Hansen are demonized precisely because they represent the public face of the enemy. In skeptic circles they are treated like Hitler and Stalin, to be despised as the head of a pernicious evil. Those guys must have huge cojones to not just walk away from it all.

My daughter gave me two grandkids and they are wonderful. Enjoy!

Frankly, I can't take anything you say with any degree of seriousness. Hitler and Stalin? Please retract the statement and redeem some credibility.

[Vergent]

Oh don't worry, he'll have come creative way of pointing out he didn't really predict what he predicted. He'll just change it...he's good at that.

In a landmark 1988 study, Hansen predicted that if greenhouse gas emissions continue, which they have, Washington, D.C., would have about nine days each year of 95 degrees or warmer in the decade of the 2010s. So far this year, with about four more weeks of summer, the city has had 23 days with 95 degrees or hotter temperatures.

Thus he admits he was wrong, it is worse than he predicted.

[donsutherland1]

Too bad they don't have the cajones to come out and debate their ideas.

They do. They put their ideas out in the literature and those ideas are challenged in the peer review process. That's where the debate takes place.

Those taking a contrarian position have largely chosen not to participate. Their non-participation in the peer review process is solely their own choice. Choices have consequences.

[Vergent]

They do. They put their ideas out in the literature and those ideas are challenged in the peer review process. That's where the debate takes place.

Those taking a contrarian position have largely chosen not to participate. Their non-participation in the peer review process is solely their own choice. Choices have consequences.

but first you must get a degree, and before that you have to go to school, and before that you have to learn how to think.

[PhillipS]

Those guys get paid handsomely to do what they do. They aren't walking away, they enjoy the attention which only helps build upon their delusions. Too bad they don't have the cajones to come out and debate their ideas.

What nonsense you spew! "Paid handsomely"? Clearly you've never compared the salaries of professional climatologists to, say, professional athletes - where a kid who has to have his contract read to him because he's functionally illiterate can earn a signing bonus greater than Dr. Hansen will earn in his entire career.

And as for who has the larger cojones - scientists put their work out there in the scientific press to be reviewed, dissected, criticized and ridiculed if wrong. That's honest debate - and they take part in it every day of their careers. That's a lot tougher than posting on a blog where you can post anything you want and you can censor opposing views or close comments completely.

Scientists don't hide behind anonymous internet handles, either - Dr. James Hansen is exactly who he says he is. As are the other climatologists in academia and government. A lot of them have received loads of vitriolic emails and phone calls from the denialist fringe. It takes sizable cojones to choose a career that you know will draw down the wrath of the lunatic fringe.

[WeatherRusty]

Frankly, I can't take anything you say with any degree of seriousness. Hitler and Stalin? Please retract the statement and redeem some credibility.

You have apparently not been involved in this debate for long or experienced the vitriol spewed by some toward climate scientists. Trust me, there are those out there who loath and despise Hansen and Mann. To some people these scientists are attempting to destroy industrialized civilization and/or deprive people of their freedom. To those people that's what this debate is all about.

[bluewave]

Here's a recent discussion of the paper:

http://www.columbia....803_DiceQNA.pdf

[Conclue]

Why are people here holding on to model projections from 1988 as if they have valid credibility versus climate models today? Are we really seirious right now? The same people that are attacking his 1988 projections and his lacking "hey my projections were wrong rant" as if he's doing it intentionally to hide something are the same ones acting as if they have no basic numerical weather prediction knowledge and have no idea that models from 1988 are JUNK compared to those today. It's probably silly to even mention it but of course it's a double edged sword.

Unbelievable. I don't understand how we as a society live in a world where many people stay seemingly absent from the world in which they live. There's been more extreme weather and intense heatwaves in the past decade than usual. It's everywhere, all over and people just continue to walk around and deny climate change as they experience as if they have absolutely no sense whatsoever. You don't need a climatologist to tell you that your planet is changing. If you can't see it for yourself then I don't know what the fate of this planet will be when it's inhabitants don't even recognize it's existence.

Hansens a solider. Good for him.

[ORH_wxman]

Why are people here holding on to model projections from 1988 as if they have valid credibility versus climate models today? Are we really seirious right now? The same people that are attacking his 1988 projections and his lacking "hey my projections were wrong rant" as if he's doing it intentionally to hide something are the same ones acting as if they have no basic numerical weather prediction knowledge and have no idea that models from 1988 are JUNK compared to those today. It's probably silly to even mention it but of course it's a double edged sword.

Unbelievable. I don't understand how we as a society live in a world where many people stay seemingly absent from the world in which they live. There's been more extreme weather and intense heatwaves in the past decade than usual. It's everywhere, all over and people just continue to walk around and deny climate change as they experience as if they have absolutely no sense whatsoever. You don't need a climatologist to tell you that your planet is changing. If you can't see it for yourself then I don't know what the fate of this planet will be when it's inhabitants don't even recognize it's existence.

Hansens a solider. Good for him.

Very good point...we don't. Its always changing.

The rest of this is pretty disingenuous...while I agree its not fair to just point to his 1988 models, its also not fair for him to compare 1951-1980 to the current and claim that because we are more extreme than that period, that we can jump to major conclusions because of that. He left out the way more extreme 1930s which by far has the most record high temps and record low temps than any decade along with the worst drought conditions we've seen in the U.S. It was far more extreme than what we've seen this decade.

His shift to the right in the normal distribution is correct...we are warmer. The drastic claims about extreme weather though still leave a lot to be desired. We know its more extreme than 1951-1980.

[rygar]

You have apparently not been involved in this debate for long or experienced the vitriol spewed by some toward climate scientists. Trust me, there are those out there who loath and despise Hansen and Mann. To some people these scientists are attempting to destroy industrialized civilization and/or deprive people of their freedom. To those people that's what this debate is all about.

You compared "deniers" to mass murderers ... and then defended the position.

[skierinvermont]

For reliable information on how much and why Hansen's 1988 projection was too warm go here:

The short answer:

1. GHG forcing was between Scenario B and C. Comparisons only to scenario A are cherry picking. Actual forcing was 16% below scenario B.

2. Temperatures rose 15-25% faster than a recreated scenario with actual GHG forcing (let's call this scenario B'). In other words, the earth warmed 15-25% faster than Hansen's model projects if you input actual GHG concentrations from the last 25 years.

3. This is because Hansen used a climate sensitivity in his model of 4.2C to CO2 doubling. If you read his paper, he explains that his selection of a sensitivity of 4.2C was somewhat arbitrary and actual sensitivity is not known precisely. If you lower the model sensitivity to 3.5C, the model accurately reproduces the past 25 years of temperatures. Hansen wasn't W-R-O-N-G nor was his paper. It was a projection based on very clear assumptions about GHG concentrations and climate sensitivity. Attacking Hansen personally or attacking his paper are unhelpful to improving our knowledge. The correct response is too look at how we can improve the underlying assumptions.

http://www.skepticalscience.com/Hansen-1988-prediction-advanced.htm

[skierinvermont]

You compared "deniers" to mass murderers ... and then defended the position.

I believe you mis-read him.

[ORH_wxman]

For reliable information on how much and why Hansen's 1988 projection was too warm go here:

The short answer:

1. GHG forcing was between Scenario B and C. Comparisons only to scenario A are cherry picking. Actual forcing was 16% below scenario B.

2. Temperatures rose 15-25% faster than a recreated scenario with actual GHG forcing (let's call this scenario B'). In other words, the earth warmed 15-25% faster than Hansen's model projects if you input actual GHG concentrations from the last 25 years.

3. This is because Hansen used a climate sensitivity in his model of 4.2C to CO2 doubling. If you read his paper, he explains that his selection of a sensitivity of 4.2C was somewhat arbitrary and actual sensitivity is not known precisely. If you lower the model sensitivity to 3.5C, the model accurately reproduces the past 25 years of temperatures. Hansen wasn't W-R-O-N-G nor was his paper. It was a projection based on very clear assumptions about GHG concentrations and climate sensitivity. Attacking Hansen personally or attacking his paper are unhelpful to improving our knowledge. The correct response is too look at how we can improve the underlying assumptions.

http://www.skeptical...on-advanced.htm

A couple questions...well first a statement...we obviously know that Hansen predicted too high of a sensivity.

Now the questions:

1. Did he fail to take into account aerosols and methane? CO2 has risen about like scenario B but the total emmissions are a bit below that.

2. That makes the model incorrect, but not as incorrect as it would first seem if we take that into account...but then that means Hansen missed out on the ratio of the other contributions?

I actually find the AR4 models more troubling considering they are newer and their emmissions have been adjusted...and we are near their top scenario but are certainly going to struggle to stay within shouting distance of their projection over the next decade or two.

[WeatherRusty]

You compared "deniers" to mass murderers ... and then defended the position.

Are you serious? I did nothing of the sort.

Now I will ask you for an apology for your mistake. The Heartland Institute has resorted to that type shock value publicity, not me.

[Jonger]

Hansen's 1981 forecast came in on the low side.

You can agree or disagree with his statement on the 1988 call. The common

denominator in all his calls is that he correctly predicted that we would warm between 1980 and

now and that it would have important implications.

I am not sure why people get so mad at Hansen. He even disagreed with many politicians on

how do best deal with emissions. He was looking out for the average person against to concentrated

power of big government and big business.

http://www.nytimes.c...n/07hansen.html

With natural gas prices dropping and CAFE standards, coupled with high gas prices..... Co2 decreases are basically in freefall.

China is building windfarms faster then anyone on earth... Your gripe is with the 3rd world... I bet we reduce co2 ppm yearly increase to below 0.5 by 2025.

[Jonger]

http://www.skepticalscience.com/Hansen-1988-prediction.htm

Skeptical Science thinks scenario B took place.... Are they serious? It was scenario C without a doubt. This is wishcasting and looking at a situation with Biased goggles.... Hanson nailed scenerio C.

[Conclue]

Very good point...we don't. Its always changing.

The rest of this is pretty disingenuous...while I agree its not fair to just point to his 1988 models, its also not fair for him to compare 1951-1980 to the current and claim that because we are more extreme than that period, that we can jump to major conclusions because of that. He left out the way more extreme 1930s which by far has the most record high temps and record low temps than any decade along with the worst drought conditions we've seen in the U.S. It was far more extreme than what we've seen this decade.

His shift to the right in the normal distribution is correct...we are warmer. The drastic claims about extreme weather though still leave a lot to be desired. We know its more extreme than 1951-1980.

I agree with what your saying as I wondered how he would come so strong so quickly. I'm actually very interested in obtaining this paper and reading it through and through. I'm interested in how he went about constructing his data set and what methods he used to analyze it.

What I got the most out of school with my climate courses versus climate change is that theres always going to be room for one to argue either way. It's overwhelmingly difficult to say specifc events are blamed on global warming soley, however at the same point, it's hard to not aruge that for instance the 30's weren't just one of those wildly extreme years of natural climate variability. Extracting that signal and discerning between another is (in my mind) nearly impossible so I am looking foward to this paper. Could one even argue that the 1930's was one of the first signals of a warming world where both natural and anthropogenic forces worked together in a seemingly coherent way? It's difficult to say. I would imagine no because of the concentration of GHGs, however a favorable pattern could possibly have enhanced the effect.

There's so much more that says the climate is changing rapidly then doesn't that I don't understand why we are not moving foward in handling this problem. We can't have this continuing on and on. That arctic is in trouble and then we're really gonna have problems. At the end of the day waiting for things to spiral out of control will not be the time to prove or disprove global warming but a time to really suffer the consquences.

[Jonger]

I agree with what your saying as I wondered how he would come so strong so quickly. I'm actually very interested in obtaining this paper and reading it through and through. I'm interested in how he went about constructing his data set and what methods he used to analyze it.

What I got the most out of school with my climate courses versus climate change is that theres always going to be room for one to argue either way. It's overwhelmingly difficult to say specifc events are blamed on global warming soley, however at the same point, it's hard to not aruge that for instance the 30's weren't just one of those wildly extreme years of natural climate variability. Extracting that signal and discerning between another is (in my mind) nearly impossible so I am looking foward to this paper. Could one even argue that the 1930's was one of the first signals of a warming world where both natural and anthropogenic forces worked together in a seemingly coherent way? It's difficult to say. I would imagine no because of the concentration of GHGs, however a favorable pattern could possibly have enhanced the effect.

There's so much more that says the climate is changing rapidly then doesn't that I don't understand why we are not moving foward in handling this problem. We can't have this continuing on and on. That arctic is in trouble and then we're really gonna have problems. At the end of the day waiting for things to spiral out of control will not be the time to prove or disprove global warming but a time to really suffer the consquences.

Fortunately for the earth, cheap fossil fuel is quickly becoming harder to come by. wind and solar is quickly becoming cheaper then easily obtainable fossil fuels. Natural gas is already putting coal on the decline rapidly.

[Entropy]

Why are people here holding on to model projections from 1988 as if they have valid credibility versus climate models today? Are we really seirious right now? The same people that are attacking his 1988 projections and his lacking "hey my projections were wrong rant" as if he's doing it intentionally to hide something are the same ones acting as if they have no basic numerical weather prediction knowledge and have no idea that models from 1988 are JUNK compared to those today. It's probably silly to even mention it but of course it's a double edged sword.

Unbelievable. I don't understand how we as a society live in a world where many people stay seemingly absent from the world in which they live. There's been more extreme weather and intense heatwaves in the past decade than usual. It's everywhere, all over and people just continue to walk around and deny climate change as they experience as if they have absolutely no sense whatsoever. You don't need a climatologist to tell you that your planet is changing. If you can't see it for yourself then I don't know what the fate of this planet will be when it's inhabitants don't even recognize it's existence.

Hansens a solider. Good for him.

Still the models have been overestimating the sensitivity of the climate (or underestimating the effects of natural variation). As the BEST study team demonstrated, we have already experience 2.5C of warming (at least on land) since 1750. The BEST analysis included by far the most amount of data and employed the most advanced statistical tools in developing its global temperature record. I'm not convinced that there attribution efforts were entirely correct. It would seem they entirely neglected natural variation that even mainstream climate science acknowledges that led to the end of the LIA. Nevertheless, the warming estimate would seem consistent with observations from that era which, although sparse, would certainly support a much cooler climate.

If we have managed to not only weather 2.5C of warming over the past ~250 years (and nearly 1.5C in the past ~70 years), but also experience explosive growth in wealth and population during the same time frame, it's hard to be overly alarmed about another 2C of warming in the next 100 years. Even the IPCC admits that the benefits of warming would largely equal or exceed the negatives at least up to 2C above the late 20th Century means. Moreover, we can adapt to a lot of the negative effects. The heat waves in 2011 and 2012 were a lot less deadly than predecessors in earlier years due to increased awareness and access to air conditioning. But on a more general level, who gets to say what is the best climate? A warmer climate would likely be a boon to the northern U.S. and Canada.

[skierinvermont]

Still the models have been overestimating the sensitivity of the climate (or underestimating the effects of natural variation). As the BEST study team demonstrated, we have already experience 2.5C of warming (at least on land) since 1750. The BEST analysis included by far the most amount of data and employed the most advanced statistical tools in developing its global temperature record. I'm not convinced that there attribution efforts were entirely correct. It would seem they entirely neglected natural variation that even mainstream climate science acknowledges that led to the end of the LIA. Nevertheless, the warming estimate would seem consistent with observations from that era which, although sparse, would certainly support a much cooler climate.

If we have managed to not only weather 2.5C of warming over the past ~250 years (and nearly 1.5C in the past ~70 years), but also experience explosive growth in wealth and population during the same time frame, it's hard to be overly alarmed about another 2C of warming in the next 100 years. Even the IPCC admits that the benefits of warming would largely equal or exceed the negatives at least up to 2C above the late 20th Century means. Moreover, we can adapt to a lot of the negative effects. The heat waves in 2011 and 2012 were a lot less deadly than predecessors in earlier years due to increased awareness and access to air conditioning. But on a more general level, who gets to say what is the best climate? A warmer climate would likely be a boon to the northern U.S. and Canada.

You are making an apples to orange comparison. One you are comparing land only temperature observations to land-ocean temperature forecasts. Second, you are comparing a 250 year period to a 100 year period.

The apples to apples comparison is this. .8C of warming globally (land + ocean) 1900-2000, 3C 2000-2100.

A rate of nearly 4X.

Moreover, even the much subued rate of warming we have already experienced is already exhibiting costs and damages in form of more severe flooding heatwaves and other extreme weather phenomenon. Even more difficult to detect are the slower changes in the means which incur adaptation costs.

[bluewave]

With natural gas prices dropping and CAFE standards, coupled with high gas prices..... Co2 decreases are basically in freefall.

China is building windfarms faster then anyone on earth... Your gripe is with the 3rd world... I bet we reduce co2 ppm yearly increase to below 0.5 by 2025.

I guess the main problem is that tough economic conditions around the world will continue to put carbon emissions

reduction low down on the to do list for many countries.

http://www.businessi...ggernaut-2012-6

[skierinvermont]

http://www.skeptical...-prediction.htm

Skeptical Science thinks scenario B took place.... Are they serious? It was scenario C without a doubt. This is wishcasting and looking at a situation with Biased goggles.... Hanson nailed scenerio C.

You did not understand what was written. Re-read more carefully and get back to us.

[Msalgado]

We can't ignore them Friv. They represent a major force to be overcome if we have any hope of a sustainable future free from the perils of climate change. The tentacles of denial reach all the way to the highest places of influence. They are not interested in the science. They are political ideologues invested in a world view that does not permit things like global warming and biological evolution. Our battle is huge and I believe will only be won beginning at the grassroots level.

These people are being taken advantage of by a higher order of self interested, very powerful and rich scum bags. Of course part of their plan is to accuse us of the same thing. Difference is, we really do have science on our side.

This is ridiculous. You can and you should ignore them. This is a science based discussion forum not a policy forum. All you do is drag the conversation through the mud when you argue with people who don't acknowledge facts.

[Msalgado]

but first you must get a degree, and before that you have to go to school, and before that you have to learn how to think.

You do not need a degree to be published in a peer reviewed journal.

[Jonger]

You are making an apples to orange comparison. One you are comparing land only temperature observations to land-ocean temperature forecasts. Second, you are comparing a 250 year period to a 100 year period.

The apples to apples comparison is this. .8C of warming globally (land + ocean) 1900-2000, 3C 2000-2100.

A rate of nearly 4X.

Moreover, even the much subued rate of warming we have already experienced is already exhibiting costs and damages in form of more severe flooding heatwaves and other extreme weather phenomenon. Even more difficult to detect are the slower changes in the means which incur adaptation costs.

While I fully support drastic improvement of renewable and phasing out fossil fuel, argueing that we have economically suffered from 0.8 degrees of warming is halarious when compared to the expense of non-fossil fuels today. To keep the world running with renewables today would put the majority of the 3rd world in the stone age.

It's even debatable if we have suffered even a dollars worth of damage from climate change. Human lifespan and health worldwide is far better then 200 years ago due to fossil fuel utilization.

[skierinvermont]

A couple questions...well first a statement...we obviously know that Hansen predicted too high of a sensivity.

Now the questions:

1. Did he fail to take into account aerosols and methane? CO2 has risen about like scenario B but the total emmissions are a bit below that.

2. That makes the model incorrect, but not as incorrect as it would first seem if we take that into account...but then that means Hansen missed out on the ratio of the other contributions?

I actually find the AR4 models more troubling considering they are newer and their emmissions have been adjusted...and we are near their top scenario but are certainly going to struggle to stay within shouting distance of their projection over the next decade or two.

My main objection continues to be that you are treating Hansen's paper as if it was meant to be a definitive prediction. It wasn't. It was just a projection where he essentially says well if we assume XY and Z something like AB and C may occur. He specifically states that the sensitivity used of 4.2C is on the high side of the National Academy of Science estimate of 3 +/- 1.5.

So to respond to your statement and to your questions.

First to your statement, we do not know that 4.2C is too high of a sensitivity although it very likely is. If the aerosol negative forcing is on the high side of current estimates, it would be probable that climate sensitivity is over 4C. That would be the only way we could have observed 20th century warming based on a smaller net forcing. Which is why mainstream estimates continue to be 2-4.5C with a mean of 3C. Is it likely that it is 4.2C? Not at all. Impossible? I would not say that either.

To your first question: scenario B included a faster pace of methane increase than has occurred. The other big discrepancy between scenario B and reality is CFCs which are significant GHGs but were curbed by the montreal protocol. I am unsure about aerosols.

To your second question: I would rephrase. It doesn't make the model incorrect. It makes the assumption of 4.2C climate sensitivity probably incorrect, unless aerosol forcing is larger than thought.

One thing I am very confused about at the moment is aerosols. If I am reading correctly, he did include negative forcing from aerosols prior to 1980 in the hindcast but in the future projections there is no negative forcing from aerosols. I am not sure how that assumption stands up. Humans have curbed emissions.. but have aerosols plateaued (it depends on the type and altitude of aerosols as well)? Plus nobody really knows how strong of a forcing aerosols are anyways. They could be very weak, which would argue for a lower climate sensitivity. Or very strong, which would argue for a higher climate sensitivity.