Climate Change - General Discussion : Read the Mod Note in post #1 before posting

Akrasia

Gaoth Laidir wrote: »

But...but...just a few days ago you said to me that you...

...

So for that reason it's move along, nothing to see here, yes?

Did you read the study?

Gaoth Laidir

Akrasia wrote: »

Did you read the study?

Of course. Why?

Akrasia

Gaoth Laidir wrote: »

Of course. Why?

Because you didnt refer to the study at all in your reply.

The underlying physics of climate change is not in doubt to any great extent. Warmer air holds more water. Rainfall events when they happen, will be more intense.

The uncertainty regarding irish climate is in the frequency and distribution of these events given that were on the edge of a continent and our weather is inherently changeable on the frontier of oceanic and continental air masses.

This study looked at scenarios and discussed them based on their impact and how frequently they showed up in the models. The study shows the potential for severe flooding in the high impact events but even in the low impact scenarios there is a very significant increased flood risk for Ireland.

enfant terrible

Does this mean we will be getting a lot more heatwaves during our Irish summers? That would be great.

Akrasia

enfant terrible wrote: »

Does this mean we will be getting a lot more heatwaves during our Irish summers? That would be great.

It means if there are heatwaves, they're likely to be hotter, but the factors involved in irish weather are complex so we may not have more hot weather events.

Gaoth Laidir

Akrasia wrote: »

Because you didnt refer to the study at all in your reply.

The underlying physics of climate change is not in doubt to any great extent. Warmer air holds more water. Rainfall events when they happen, will be more intense.

The uncertainty regarding irish climate is in the frequency and distribution of these events given that were on the edge of a continent and our weather is inherently changeable on the frontier of oceanic and continental air masses.

This study looked at scenarios and discussed them based on their impact and how frequently they showed up in the models. The study shows the potential for severe flooding in the high impact events but even in the low impact scenarios there is a very significant increased flood risk for Ireland.

I was pointing out the fact that when it suits you disregard localised forecasts for Ireland, yet a few days later you're happy to quote a study that not only refers to Ireland but pinpoints cities. Which is it?

Most of the problem with city flooding is down to development issues and blockage/redirection of flood channels. More people using the same systems means more problems. Lack of maintenance of such systems (e.g. the annual blockage due to leaves in Autumn.

Developments on natural flood plains. Lack of construction of flood defenses. Lack of dredging of the Shannon. And so on.

I especially like this comment:

“We are already seeing at first hand the implications of extreme weather events in our capital cities. In Paris the Seine rose more than 4 metres above its normal water level. And as Cape Town prepares for its taps to run dry, this analysis highlights that such climate events are feasible in European cities too.”

So she's able to attribute single events like Paris flooding to GHGs? Cape Town's water issues likewise? I didn't see any references to back up these claims. It's a paper full of more horror stories as it's designed to deliver maximum impact to policy makers.

The study, and of course your quotes, focus on the very highest impact figures of RCP8.5. That is unlikely to occur.

Have YOU read the whole paper or just the summary you linked to?

gluppers

Are we possibly talking 2010 levels here?

thomasj

gluppers wrote:

Are we possibly talking 2010 levels here?

I have heard comparisons to 1982

dense

Gaoth Laidir wrote: »

I was pointing out the fact that when it suits you disregard localised forecasts for Ireland, yet a few days later you're happy to quote a study that not only refers to Ireland but pinpoints cities. Which is it?

Most of the problem with city flooding is down to development issues and blockage/redirection of flood channels. More people using the same systems means more problems. Lack of maintenance of such systems (e.g. the annual blockage due to leaves in Autumn.

Developments on natural flood plains. Lack of construction of flood defenses. Lack of dredging of the Shannon. And so on.

I especially like this comment:



So she's able to attribute single events like Paris flooding to GHGs? Cape Town's water issues likewise? I didn't see any references to back up these claims. It's a paper full of more horror stories as it's designed to deliver maximum impact to policy makers.

The study, and of course your quotes, focus on the very highest impact figures of RCP8.5. That is unlikely to occur.

Have YOU read the whole paper or just the summary you linked to?

It's definitely one the IPCC will seize upon, irrespective of Paris being flooded to a worse degree in 1910.

Seems right up their street, catastrophe wise.

dense

enfant terrible wrote: »

Does this mean we will be getting a lot more heatwaves during our Irish summers? That would be great.

Could be, maybe not. Depends on lots of factors.

The science isn't settled you see.

What we can say with a high level of confidence is that we will still have weather, some "good" and some "bad".

The "bad" will be claimed to be evidence of man made climate change, the "good" will just be weather.

dense

Shock:
Mind blowing discovery at West Antarctic Icesheet:

A glaciologist from the University of Otago in New Zealand claims her mind blew after discovering that new ice was forming beneath the Ross Ice Shelf with sea water actually freezing onto the base of the ice instead of melting it.

"It blew our minds,” says Christina Hulbe, a glaciologist from the University of Otago in New Zealand, who co-led the expedition.

And Craig Stevens, (whose mind also blew) an oceanographer from the National Institute of Water and Atmospheric Research in New Zealand, who participated in the expedition said it's important to understand because “if we get the circulation wrong, then we’re getting the melting wrong.”

Yes, Craig, it is important not to be getting the melting wrong.

We can't be doing with having new ice forming what with all the heat hiding in the oceans.

https://news.nationalgeographic.com/2018/02/ross-ice-shelf-bore-antarctica-freezing/



In other news, I wish I'd bought those clip on ice-gripper things for my shoes in Aldi last year.

sryanbruen

enfant terrible wrote: »

Does this mean we will be getting a lot more heatwaves during our Irish summers? That would be great.

That would depend on a lot of normal external factors that influence our weather on a monthly, daily, annual basis etc like the NAO setup which has been unusually and frequently negative for every Summer since 2007 bar 2013 and 2017, never mind things like climate change or global warming.

dense

Climate change responsible for decrease in Alaska snowfalls.

https://www.fws.gov/alaska/climate/inak.htm


Climate change responsible for increase in Alaska snowfalls.

https://www.scientificamerican.com/article/climate-change-has-doubled-snowfall-in-alaska/

Akrasia

dense wrote: »

Climate change responsible for decrease in Alaska snowfalls.

https://www.fws.gov/alaska/climate/inak.htm


Climate change responsible for increase in Alaska snowfalls.

https://www.scientificamerican.com/article/climate-change-has-doubled-snowfall-in-alaska/

Sorry but I've had to take a break from ignoring Dense to point out how ludicrously dishonest this post was.

From the link that dense says is a decrease in Alaskan snowfall

Observed warming in Alaska has been accompanied by a 30% increase in precipitation between 1968 and 19901. Total precipitation in the Arctic has increased at a rate of about 1% per decade over the past century. However, on the Kenai Peninsula, precipitation records between 1944 and 2002 indicate a nearly 40% decrease in the mean annual water balance, which is the difference between precipitation and potential evapotranspiration4.

If anyone still thinks Dense has any credibility, you need to click on the links and find out for yourself that they usually say the opposite of what he claims they say.

In this instance, Alaska overall is seeing a very significant increase in precipitation, but one region has seen a big shift in water balance, which means that the rate of water loss from evapotranspiration has increased while precipitation has decreased due to local climactic factors.

For him to say that these two sources contradict each other is completely misrepresenting these sources.

Akrasia

sryanbruen wrote: »

That would depend on a lot of normal external factors that influence our weather on a monthly, daily, annual basis etc like the NAO setup which has been unusually and frequently negative for every Summer since 2007 bar 2013 and 2017, never mind things like climate change or global warming.

The NAO and other 'external' factors will also be influenced by Global warming. So while these oscillations drive our weather, global climate changes will affect these oscillations.
The temperature gradients between the arctic and the lower latitudes is already decreasing and this is already affecting the jet stream. This is only going to get more pronounced as the fastest warming parts of the world continue to be the poles

Akrasia

Gaoth Laidir wrote: »

I was pointing out the fact that when it suits you disregard localised forecasts for Ireland, yet a few days later you're happy to quote a study that not only refers to Ireland but pinpoints cities. Which is it?

I don't disregard local forecasts, I regard them in proportion to the confidence attached to those forecasts.

There is uncertainty about Irelands future climate in terms of if we will see a net increase or decrease in rainfall and wind and number of stormy days, but there is a stronger agreement that there will be an increase in the intensity of events when we do experience them.

This study refers to extreme events, peak river flows, not average weather.

Most of the problem with city flooding is down to development issues and blockage/redirection of flood channels. More people using the same systems means more problems. Lack of maintenance of such systems (e.g. the annual blockage due to leaves in Autumn.
Developments on natural flood plains. Lack of construction of flood defenses. Lack of dredging of the Shannon. And so on.

I especially like this comment:



So she's able to attribute single events like Paris flooding to GHGs? Cape Town's water issues likewise? I didn't see any references to back up these claims. It's a paper full of more horror stories as it's designed to deliver maximum impact to policy makers.

The attribution of climate to extreme events is in the additional impact that was caused by the increased rainfall/heatwaves. The way these things tend to work is that the infrastructure can absorb weather events up to a limit, but when that limit is reached, any additional intensity has severe impacts.

Would the Seine have risen as much if every flood protection measure was working at peak efficiency? No, but also, would every flood protection measure have been pushed beyond their capacity if it wasn't for the additional rainfall?

Human settlement and land use changes will continue to impact river systems and they will always be sub optimal, but will be exasperated by an additional surge in precipitation levels as climate change increases the capacity for the atmosphere to hold more water.

The study, and of course your quotes, focus on the very highest impact figures of RCP8.5. That is unlikely to occur.

The worst impacts are unlikely but still within a range that we ought to be concerned about especially as we are still on the RCP 8.5 trend line for emissions and we don't seem to be putting enough resources into our transition away from RCP 8.5. Even the most likely impacts from a RCP 8.5 scenario are still very significant flood risks for our cities.

Have YOU read the whole paper or just the summary you linked to?

Yes I have.

dense

Akrasia wrote: »

In this instance, Alaska overall is seeing a very significant increase in precipitation, but one region has seen a big shift in water balance, which means that the rate of water loss from evapotranspiration has increased while precipitation has decreased due to local climactic factors.

For him to say that these two sources contradict each other is completely misrepresenting these sources.

Deliberate avoidance of using either the word "snowfall" or "climate change" in that fudge of an "explanation".

Quite telling Akrasia, quite telling....

sryanbruen

Far wider area of thicker ice this year than 10 years ago.

Deank

sryanbruen wrote: »

Far wider area of thicker ice this year than 10 years ago.

Global warming my hole :pac:

Abstract


Ice-core records show that climate changes in the past have been large, rapid, and synchronous over broad areas extending into low latitudes, with less variability over historical times. These ice-core records come from high mountain glaciers and the polar regions, including small ice caps and the large ice sheets of Greenland and Antarctica.


As the world slid into and out of the last ice age, the general cooling and warming trends were punctuated by abrupt changes. Climate shifts up to half as large as the entire difference between ice age and modern conditions occurred over hemispheric or broader regions in mere years to decades. Such abrupt changes have been absent during the few key millennia when agriculture and industry have arisen. The speed, size, and extent of these abrupt changes required a reappraisal of climate stability. Records of these changes are especially clear in high-resolution ice cores. Ice cores can preserve histories of local climate (snowfall, temperature), regional (wind-blown dust, sea salt, etc.), and broader (trace gases in the air) conditions, on a common time scale, demonstrating synchrony of climate changes over broad regions.

The Greenland records show that climate changes have been very large, rapid, and widespread. Coolings were achieved in a series of steep ramps or steps and warmings in single steps. The more dramatic of the warmings have involved ≈8°C warming (8, 25) and ≈2× increases in snow accumulation (9), several-fold or larger drops in wind-blown materials (17), and ≈50% increase in methane, indicating large changes in global wetland area (5, 24).

For the best-characterized warming, the end of the Younger Dryas cold interval ≈11,500 years ago, the transition in many ice-core variables was achieved in three steps, each spanning ≈5 years and in total covering ≈40 years (26). However, most of the change occurred in the middle of these steps. The warming as recorded in gas isotopes occurred in decades or less (8). The most direct interpretation of the accumulation-rate record is that snowfall doubled over 3 years and nearly doubled in 1 year (9). Several records show enhanced variability near this and other transitions, including “flickering” behavior in which climate variables bounced between their “cold” level and their “warm” level before settling in one of them (27).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC34297/

Interesting stuff, especially from high resolution ice cores.

Around 15,000 years ago, the Earth started warming abruptly after ~ 100,000 years of an "ice age"; this is known as a glacial termination. The large ice sheets, which covered significant parts of North America and Europe, began melting as a result. A climatic optimum known as the "Bölling-Allerød" was reached shortly thereafter, around 14,700 before present. However, starting at about 12,800 BP, the Earth returned very quickly into near glacial conditions (i.e. cold, dry and windy), and stayed there for about 1,200 years: this is known as the Younger Dryas (YD), since it is the most recent interval where a plant characteristic of cold climates, Dryas Octopetala, was found in Scandinavia.

The most spectacular aspect of the YD is that it ended extremely abruptly (around 11,600 years ago), and although the date cannot be known exactly, it is estimated from the annually-banded Greenland ice-core that the annual-mean temperature increased by as much as 10°C in 10 years.

http://ocp.ldeo.columbia.edu/res/div/ocp/arch/printer.shtml

StringerBell

Climate change deniers are a strange breed. Wandered into the wrong thread by accident.

dense

As the Global Warming theory continues to unravel, climate alarmists are bound to try to blame our current snow event on man made "climate change".

Don't bother.

Breaking News

This is weather, not "climate change".

Maynooth Climate Change Professor* says it would require "a very long stretch" to link our current weather event to "Climate Change" and instead, it is something that happens every 20 to 30 years.

Retired "climate change expert" Professor John (of co2 in human breath causes climate change fame :pac::pac:) Sweeney must have been pulling his hair out watching it.

See *Professor Thorne on Prime Time here, last portion.

http://www.rte.ie/player/show/10846164

The alarmists here in this thread (in an obvious state of denial) couldn't hear Professor Sweeney recently saying that Co2 in human breath is causing problems in the Arctic, so I doubt they'll hear Professor Thorne saying what he said either.

Casualsingby

sryanbruen wrote: »

Far wider area of thicker ice this year than 10 years ago.

What was the state of the ice in 05,06,07,09 and 13,14,15,16,17? I'm on the fence with this subject, picking any 2 charts could yield any results for pro and against I'd imagine. And if you went back every 10 years what is like in 28th Feb 98,88,78,68,58,48,38,28,18,08 that would actually paint a clearer picture for a fence sitter like me.

sryanbruen

Casualsingby wrote: »

What was the state of the ice in 05,06,07,09 and 13,14,15,16,17? I'm on the fence with this subject, picking any 2 charts could yield any results for pro and against I'd imagine. And if you went back every 10 years what is like in 28th Feb 98,88,78,68,58,48,38,28,18,08 that would actually paint a clearer picture for a fence sitter like me.

Going back to 1978, you can check out images of the arctic sea ice extent over the northern hemisphere in the link below. I'm far from an expert in these kinds of things so anything I say here is just something I find or think of in regards to the topics of climate change or global warming. I'm not a denier of global warming but I always have questions of skepticism about it like how can we say 2016 was the warmest year ever on record if we have records only going back to a certain period? We don't have millions of years of historical data after all. That's a problem with data in general.

So I'm just a lurker around here and I'm learning about the topics. Any time Ireland's climate or weather history is involved or mentioned though, I will get involved in the discussion.

http://nsidc.org/data/seaice_index/archives/image_select

dense

Casualsingby wrote: »

What was the state of the ice in 05,06,07,09 and 13,14,15,16,17? I'm on the fence with this subject, picking any 2 charts could yield any results for pro and against I'd imagine. And if you went back every 10 years what is like in 28th Feb 98,88,78,68,58,48,38,28,18,08 that would actually paint a clearer picture for a fence sitter like me.

Direct and accurate observations are in their infancy.
This is after all, a new "science".

The scientific community is examining a minute slice (less than 40 years of satellite data) of history and trying to contextualise it without having anything to compare it to.

Exact measurements are something of a new toy; they just did not exist a hundred years ago.

What did exist a hundred years ago though, were newspaper reports of alarmed scientists fretting that the ice was melting, even then.

https://realclimatescience.com/disappearing-glaciers/

Casualsingby

Thanks Syran I will check it on laptop later too blind for phone.Edit Guessing it has mostly shrunk since 78 after reading dense post ha.

Akrasia

Casualsingby wrote: »

What was the state of the ice in 05,06,07,09 and 13,14,15,16,17? I'm on the fence with this subject, picking any 2 charts could yield any results for pro and against I'd imagine. And if you went back every 10 years what is like in 28th Feb 98,88,78,68,58,48,38,28,18,08 that would actually paint a clearer picture for a fence sitter like me.

From sryanbruen's own chart you can see 2004-2013 10 year average line, and 2007 ended way below that average (which means it was an exceptionally bad year for Ice at that time) 2017/2018 is also well below that trend line, but the difference is that in the first chart, half the years were above that trend, the other half were below. But in the 2018 chart, pretty much every year plotted is below that trend line.

The 'global warming my hole' comment was contradicted by the very charts he was replying to.


sryanbruen, you've described yourself as a statistician. Picking two datapoints for comparison isn't really what statisticians do, you need to work with a larger dataset

In 2008 for example, the sea Ice extent was still growing way into March and didn't start to decline until the 25th of March, while in 2018, Maximum extent was reached at the start of February, and from your own graph, you can see that the rate of increase between January and February has been much slower this year compared to 10 years ago, the trend recently has been much slower ice accumulation in spring and before the melt season kicks off around May. Based on these graphs, I would expect the maximum ice extend and volumes for 2018 to be significantly lower than they were in 2008, We'll find out in June.

http://media.graytvinc.com/images/810*486/SeaIceExtent.jpg
http://www.ktuu.com/content/news/Arctic-sea-ice-sit-at-unseasonable-low-levels-475222113.html

Arctic sea ice is in terminal decline and temperatures in the arctic are alarmingly hotter than they have ever been since any kind of observations began.

d'Oracle

dense wrote: »

Retired "climate change expert" Professor John (of co2 in human breath causes climate change fame :pac::pac:) Sweeney must have been pulling his hair out watching it.

He didn't say that though.

dense

d'Oracle wrote: »

He didn't say that though.

What did he say about the problems caused in the Arctic by CO2 exhaled in human breath then?

Thanks.

dense

Casualsingby wrote: »

Thanks Syran I will check it on laptop later too blind for phone.Edit Guessing it has mostly shrunk since 78 after reading dense post ha.

Read it in conjunction with this:

https://www.telegraph.co.uk/news/earth/environment/globalwarming/11395516/The-fiddling-with-temperature-data-is-the-biggest-science-scandal-ever.html

https://notalotofpeopleknowthat.wordpress.com/2015/02/04/temperature-adjustments-transform-arctic-climate-history/