climate change intensified the amount of rainfall in recent hurricanes

[beecee]

https://phys.org/news/2018-11-climate-simulations-wetter-windier-hurricanes.html

Climate simulations project wetter, windier hurricanesNovember 14, 2018, Lawrence Berkeley National Laboratory

New supercomputer simulations by climate scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that climate change intensified the amount of rainfall in recent hurricanes such as Katrina, Irma, and Maria by 5 to 10 percent. They further found that if those hurricanes were to occur in a future world that is warmer than present, those storms would have even more rainfall and stronger winds.

Read more at: https://phys.org/news/2018-11-climate-simulations-wetter-windier-hurricanes.html#jCp

the paper:

https://www.nature.com/articles/s41586-018-0673-2

Anthropogenic influences on major tropical cyclone events

Abstract

There is no consensus on whether climate change has yet affected the statistics of tropical cyclones, owing to their large natural variability and the limited period of consistent observations. In addition, projections of future tropical cyclone activity are uncertain, because they often rely on coarse-resolution climate models that parameterize convection and hence have difficulty in directly representing tropical cyclones. Here we used convection-permitting regional climate model simulations to investigate whether and how recent destructive tropical cyclones would change if these events had occurred in pre-industrial and in future climates. We found that, relative to pre-industrial conditions, climate change so far has enhanced the average and extreme rainfall of hurricanes Katrina, Irma and Maria, but did not change tropical cyclone wind-speed intensity. In addition, future anthropogenic warming would robustly increase the wind speed and rainfall of 11 of 13 intense tropical cyclones (of 15 events sampled globally). Additional regional climate model simulations suggest that convective parameterization introduces minimal uncertainty into the sign of projected changes in tropical cyclone intensity and rainfall, which allows us to have confidence in projections from global models with parameterized convection and resolution fine enough to include tropical cyclones.

 

[mistermack]

Meanwhile, here in the UK, we've had a nice spring, lovely sunny summer, and the autumn is nice too. So it's not all bad news. No water shortages, no floods. 

Thanks, climate change. 

[NortonH]

14 hours ago, beecee said:

New supercomputer simulations by climate scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that climate change intensified the amount of rainfall in recent hurricanes such as Katrina, Irma, and Maria by 5 to 10 percent.

I kNEW computers could model this stuff!

[Sensei]

2 hours ago, mistermack said:

Meanwhile, here in the UK, we've had a nice spring, lovely sunny summer, and the autumn is nice too. So it's not all bad news. No water shortages, no floods. 

Thanks, climate change. 

Thanks to prehistoric climate change, you are on island. 6500 BC Great Britain disconnected from continental Europe.

https://en.wikipedia.org/wiki/Doggerland

 

[Ken Fabian]

 

13 hours ago, mistermack said:

Meanwhile, here in the UK, we've had a nice spring, lovely sunny summer, and the autumn is nice too. So it's not all bad news. No water shortages, no floods. 

Thanks, climate change. 

Mistermack - if one degree C of global average warming looks good to you right now where you are, is that something you expect to be an enduring condition? Do you expect things to be just as good with 3 to 6 degrees - or to be even better? Or is that you do not expect that amount of warming can take place? If where you live appears to benefit from global warming but other places suffer does that have any influence on your thinking? Do you think what happens elsewhere will have no impact on UK prosperity or security?

Whilst there are other contributors here I could ask questions like this I don't think I would get a civil discussion let alone answers. I am okay with lively discussion and disagreement but make no mistake, my own views unashamedly reflect the mainstream science based advice - which is not a matter of faith, but of trust in the institutions, practices and practitioners of science.

I will say that I think your statement above trivialises the issues. We have had close to 30 years of consistent expert advice - unchanged by whether it was commissioned by Progressives or Conservatives (or however you want to label the 'sides'). I think that is a good indicator that the understanding of crucial climate processes is correct - but then, I am of the view that those reports and studies were competently done in good faith and genuinely represent what is known and not known. 

Edited November 15, 2018 by Ken Fabian

[StringJunky]

5 minutes ago, Ken Fabian said:

 

Mistermack - if one degree C of global average warming looks good to you right now where you are, is that something you expect to be an enduring condition? Do you expect things to be just as good with 3 to 6 degrees - or to be even better? Or is that you do not expect that amount of warming can take place? If where you live appears to benefit from global warming but other places suffer does that have any influence on your thinking? Do you think what happens elsewhere will have no impact on UK prosperity or security?

Whilst there are other contributors here I could ask questions like this I don't think I would get a civil discussion let alone answers. I am okay with lively discussion and disagreement but make no mistake, my own views unashamedly reflect the mainstream science based advice - which is not a matter of faith, but of trust in the institutions, practices and practitioners of science.

I will say that I think your statement above trivialises the issues. We have had close to 30 years of consistent expert advice - unchanged by whether it was commissioned by Progressives or Conservatives. I think that is a good indicator that the understanding of crucial climate processes is correct - but then, I am of the view that those reports and studies were competently done in good faith and genuinely represent what is known and not known. 

I think he's just being smug in a joking way. Whatever the climate we have, we won't escape seal level rise.

Edited November 15, 2018 by StringJunky

[Strange]

13 hours ago, mistermack said:

Meanwhile, here in the UK, we've had a nice spring, lovely sunny summer, and the autumn is nice too. So it's not all bad news. No water shortages, no floods. 

Thanks, climate change. 

But while that may be nice for humans it can cause problems. For example, if it's not cold enough over winter certain pests may not be killed off, and that can damage crops  -  Italy has had problems with olives recently for this reason. 

[iNow]

London drainage systems specifically aren’t equipped to handle the flooding, and it’s made worse since sewage systems so often intermingle with them and blow surplus water into the Thames. 

[mistermack]

1 hour ago, iNow said:

London drainage systems specifically aren’t equipped to handle the flooding, and it’s made worse since sewage systems so often intermingle with them and blow surplus water into the Thames. 

This is historical, and there's a huge project underway to improve the sewage system :  https://en.wikipedia.org/wiki/Thames_Tideway_Scheme   

[iNow]

1 minute ago, mistermack said:

This is historical, and there's a huge project underway to improve the sewage system :  https://en.wikipedia.org/wiki/Thames_Tideway_Scheme   

I’m aware. It’s not done though, is it

[mistermack]

2 hours ago, Ken Fabian said:

Do you expect things to be just as good with 3 to 6 degrees

Citation DEFINITELY needed.

1 minute ago, iNow said:

I’m aware. It’s not done though, is it

It's being done as we type.

[iNow]

Done is a synonym for complete in the way I used it, not actively in-progress or being implemented. I won’t belabor it, though

5 minutes ago, mistermack said:

Citation DEFINITELY needed.

How can a citation be provided for a question? Should Ken link to his own post?

Edited November 16, 2018 by iNow

[mistermack]

1 minute ago, iNow said:

Done is a synonym for complete in the way I used it, not actively in-progress or being implemented. I won’t belabor it, though

I'm not sure what is the point behind your mentioning it. The problem is historical, it's being dealt with, and it's a consequence of growth of a city, and paving over of land. Anyway, climate change isn't done either, is it? Half a degree in my lifetime can hardly be called change. Tiny fluctuation would be closer.

[iNow]

I understand what you’re saying. My reason for bringing up drainage is to remind folks that this is about more than more comfortable days and a bit more rain. There are downstream consequences that such one dimensional views ignore. That’s the point. 

I used infrastructure as the easiest example to support that point. I recognize it didn’t work. That’s on me. 

[Endy0816]

5 minutes ago, mistermack said:

I'm not sure what is the point behind your mentioning it. The problem is historical, it's being dealt with, and it's a consequence of growth of a city, and paving over of land. Anyway, climate change isn't done either, is it? Half a degree in my lifetime can hardly be called change. Tiny fluctuation would be closer.

That's a global average I'm afraid.

We've been smashing record highs each year locally but barely budging the average.

[Ken Fabian]

Mistermack - the numbers were from memory, but I believe, within the expected range, depending on how our emissions in the future go. Assuming widespread agreement with you we would have no broad effort to constrain emissions, so at the high end of projections. Like this - 

 

 

[druS]

On 11/15/2018 at 7:37 AM, beecee said:

 

Climate simulations project

 

 

beecee, I'm not trying to be funny, I'd like your thoughts (from the reference paper) 'Hindcast' attribution method

Is there not a difference between a forecast and a hindcast? A difference between something that a simulation "projects" to something that it looks back on?

 

[Sensei]

11 hours ago, StringJunky said:

I think he's just being smug in a joking way. Whatever the climate we have, we won't escape seal level rise.

Sea level rise is a thing that people can easily escape by moving to higher level ground. Like on my previous example of Doggerland.

But climate change can influence underwater Gulf Stream and North Atlantic Current. That's change people won't be able to avoid and escape (other way than escaping GB and Ireland islands).

https://www.independent.co.uk/environment/gulf-stream-current-climate-change-ocean-temperature-ice-age-global-weather-a8300896.html

Gulf Stream and North Atlantic Current are responsible for unnatural (for their position on the globe) quite moderate temperatures and weather on the Great Britain and Ireland islands.

Edited November 16, 2018 by Sensei

[StringJunky]

8 hours ago, mistermack said:

Citation DEFINITELY needed.

It's being done as we type.

One thing I learned yesterday is that sea rise can also come from thermal expansion and a 1 degree rise increases the sea depth by about 0.8m.

[mistermack]

Everyone in Britain today will escape the extremes of global warming. Just by dying. Ken Fabian, you're graph shows CO2 in the atmosphere peaking at 2,000 parts per million in the year 2300. That's just the kind of crazy wild guess that makes me a sceptic. Anything goes in climate science. It's a world of activists, not scientists. There is no critical restraint. 

There's no way anybody can forecast CO2 levels that far ahead. There are so many unknowns around the corner, as well as all the knowns, like wind power and solar and nuclear. If the world was REALLY worried about CO2, they could cut emissions drastically tomorrow. The reason that they don't is that governments don't buy it, they just pay lip-service to it for election purposes. 

Speculating about the year 2300 is just crazy talk. The first fusion reactors will probably go on stream around the year 2050. Who knows what low carbon technology will be like in the year 2070? All of these fantastical projections are based on nothing changing or all trends getting worse. 

Who in the year 1840 could have forecast carbon levels in the year 2020? That's the sort of thing that's being bandied about. Ludicrous.

[StringJunky]

31 minutes ago, Sensei said:

Sea level rise is a thing that people can easily escape by moving to higher level ground. Like on my previous example of Doggerland.

But climate change can influence underwater Gulf Stream and North Atlantic Current. That's change people won't be able to avoid and escape (other way than escaping GB and Ireland islands).

https://www.independent.co.uk/environment/gulf-stream-current-climate-change-ocean-temperature-ice-age-global-weather-a8300896.html

Gulf Stream and North Atlantic Current are responsible for unnatural (for their position on the globe) quite moderate temperatures and weather on the Great Britain and Ireland islands.

Yes, they can switch off .

7 minutes ago, mistermack said:

Everyone in Britain today will escape the extremes of global warming. Just by dying. Ken Fabian, you're graph shows CO2 in the atmosphere peaking at 2,000 parts per million in the year 2300. That's just the kind of crazy wild guess that makes me a sceptic. Anything goes in climate science. It's a world of activists, not scientists. There is no critical restraint. 

There's no way anybody can forecast CO2 levels that far ahead. There are so many unknowns around the corner, as well as all the knowns, like wind power and solar and nuclear. If the world was REALLY worried about CO2, they could cut emissions drastically tomorrow. The reason that they don't is that governments don't buy it, they just pay lip-service to it for election purposes. 

Speculating about the year 2300 is just crazy talk. The first fusion reactors will probably go on stream around the year 2050. Who knows what low carbon technology will be like in the year 2070? All of these fantastical projections are based on nothing changing or all trends getting worse. 

Who in the year 1840 could have forecast carbon levels in the year 2020? That's the sort of thing that's being bandied about. Ludicrous.

We have reached the stage where we are directly affect Earth systems and need to start trying to anticipate our effects on it; we are going to make mistakes on the way. It looks like we don't have much more time to act on hindsight.

Edited November 16, 2018 by StringJunky

[mistermack]

6 minutes ago, StringJunky said:

One thing I learned yesterday is that sea rise can also come from thermal expansion and a 1 degree rise increases the sea depth by about 0.8m.

And yet wikipedia has sea level rise from 1897 to 1997 of 18cm.  Bit of a discrepancy between 18cm and 80 cm. 

"At least since 1880, the average global sea level has been rising, with about an 18 cm (7.1 in) rise from 1897 to 1997.^[1]"

https://en.wikipedia.org/wiki/Sea_level_rise  

15 minutes ago, StringJunky said:

Yes, they can switch off .

We have reached the stage where we are directly affect Earth systems and need to start trying to anticipate our effects on it; we are going to make mistakes on the way. It looks like we don't have much more time to act on hindsight.

Hindsight might see it rather differently though. We are at present in a warm interglacial period, and these don't last. The consequences of going back into the full glacial condition of the current ice-age would make a bit of global warming look like heaven. The next glaciation is already overdue according to many projections, and it might be that it's only raised CO2 that is holding back the onset. We don't know, but it WILL happen at some point, without human intervention. 

Maybe in the future, there will be the ability to create a stable climate, who knows? It's never happened before. But global freezing has been far more prevalent than global warming in the recent past.

[Strange]

53 minutes ago, mistermack said:

And yet wikipedia has sea level rise from 1897 to 1997 of 18cm.  Bit of a discrepancy between 18cm and 80 cm. 

I don't think the average sea temperature has increased by 1º, has it?

1 hour ago, mistermack said:

Ken Fabian, you're graph shows CO2 in the atmosphere peaking at 2,000 parts per million in the year 2300. That's just the kind of crazy wild guess that makes me a sceptic. 

It is not a "wild crazy guess". (That is the sort of crazy wild comment that makes people describe "sceptics" as "deniers")

It is, as the annotation shows, an extreme estimate. I would assume that this means it is reasonably unrealistic. I don't know what it is based on, but I would expect an "extreme" estimate to be based on continuing growth as in the past, with no attempts to mitigate and considering all other worst-possible inputs.

You could argue (and I wouldn't disagree) that it is irresponsible to use extreme figures without also showing the full range of estimates. If for no other reason than it winds up people like you!  

4 hours ago, druS said:

beecee, I'm not trying to be funny, I'd like your thoughts (from the reference paper) 'Hindcast' attribution method

Is there not a difference between a forecast and a hindcast? A difference between something that a simulation "projects" to something that it looks back on?

My understanding is that "hindcasting" is valid because, unlike weather forecasts, climate models are not (completely) based on changes from the current state of the system.

They model the state of the system given a set of values (insolation, CO2 level, models of heat transfer between parts of the system, feednbacks, etc). So you can plug in the values known from the past (as far as we know what they are) or predicted for the future and get a result (or range of results).

More here: https://www.skepticalscience.com/climate-models.htm

[Essay]

2 hours ago, mistermack said:

....

We are at present in a warm interglacial period, and these don't last. The consequences of going back into the full glacial condition of the current ice-age would make a bit of global warming look like heaven. The next glaciation is already overdue according to many projections, and it might be that it's only raised CO2 that is holding back the onset. We don't know, but it WILL happen at some point, without human intervention. 

Maybe in the future, there will be the ability to create a stable climate, who knows? It's never happened before. But global freezing has been far more prevalent than global warming in the recent past.

Well that's the point, isn't it; there has been intervention!

You’re right about the pending ice-age conditions that the planet should be experiencing, and about how the current CO2 levels are counteracting the current ice-age forcing (orbital or Milankovitch forcing), but you are wrong about the prospects for—as well as the predictability of—the next few hundred years.

We’ve currently bottomed out, in terms of Milankovitch forcing, for our ice age prospects.  Orbital forcing is calculated to be only increasingly warming, for the next 10,000 years, so that bet is off.

...

There’s also a year-or-so-old report about how the Human forcers have overwhelmed the Astronomical, Geophysical, and Intrinsic forcers.  So the equation for climate (per unit of time) is now a function of H, human influence, instead of being a function of A, G, and I, the astro-geo-intrinsic forcers, as it had been for many millions of years.

Are you familiar with these sorts of “chaotic attractor” graphs?  I'll try finding a link to the actual article.

CO2 levels, by the end of the century, if we keep going as we are, will be at levels not seen since 30 million years ago, according to the National Science Foundation.  That is the trajectory we are heading on, and roughly what this graph above shows--30 million years worth of change over the next few centuries--if the "H" forcing remains.

~

Edited November 16, 2018 by Essay
add links

[DirtyChai]

1 hour ago, Strange said:

It is not a "wild crazy guess". (That is the sort of crazy wild comment that makes people describe "sceptics" as "deniers")

It is, as the annotation shows, an extreme estimate. I would assume that this means it is reasonably unrealistic. I don't know what it is based on, but I would expect an "extreme" estimate to be based on continuing growth as in the past, with no attempts to mitigate and considering all other worst-possible inputs.

You could argue (and I wouldn't disagree) that it is irresponsible to use extreme figures without also showing the full range of estimates. If for no other reason than it winds up people like you!  

And it's that continued irresponsible exaggeration of extreme and unrealistic figures that makes people describe "reasonable climate change proponents" as alarmists!