Climate change and extreme events – quantifying the changing odds

[multiweb (Marc)]

A very good article.

[skysurfer]

And another one, I hope this comes true in 30 years.


https://www.smh.com.au/national/what...07-p53phg.html

[Peter Ward]

By 2050, the likes of Jones and Bolt and Kelly will be long gone. No that there won't be others to follow in their footsteps, but very much climate aware millenials will be at the helm....interesting times ahead.

[Sunfish (Ray)]

The article makes a good point about the increased risk in regional areas due to increased population. The ground is so dry everything is at risk. Perhaps insurance companies will require fire protection storage tanks and metal sprinkler systems.

[Tropo-Bob (Bob)]

Originally Posted by Sunfish

The article makes a good point about the increased risk in regional areas due to increased population. The ground is so dry everything is at risk. Perhaps insurance companies will require fire protection storage tanks and metal sprinkler systems.

Here in the cyclone prone north, houses must be built to various categories (specifications) according to the risk. Council regulations deem that houses built on the wind-exposed, beach front need to be the strongest.

Do any Councils have anything like that for houses built in the more fire prone areas? For example, for a house in a rural setting, do they need fire resistant features like a tiled or cemented veranda rather than a wooden veranda that cinders can fall upon and set alight?

[gaseous (Patrick)]

Originally Posted by Tropo-Bob

Here in the cyclone prone north, houses must be built to various categories (specifications) according to the risk. Council regulations deem that houses built on the wind-exposed, beach front need to be the strongest.

Do any Councils have anything like that for houses built in the more fire prone areas? For example, for a house in a rural setting, do they need fire resistant features like a tiled or cemented veranda rather than a wooden veranda that cinders can fall upon and set alight?

Yes Bob, it's called the Bushfire Attack Level (BAL). It's normally part of a local authority's list of planning regulations for houses adjacent to potentially bushfire-prone areas. It ranges from a low-range ember attack to full-on direct flames. The low-range rating requires sealing of gutters/downpipes, mesh screening on windows/doors, non-combustible decking materials (or timbers that meet the BAL requirements), etc. Just complying with the low-level rating can be quite onerous and expensive - I shudder to think what the high level ratings would require.

[Tropo-Bob (Bob)]

Originally Posted by gaseous

Yes Bob, it's called the Bushfire Attack Level (BAL). It's normally part of a local authority's list of planning regulations for houses adjacent to potentially bushfire-prone areas. It ranges from a low-range ember attack to full-on direct flames. The low-range rating requires sealing of gutters/downpipes, mesh screening on windows/doors, non-combustible decking materials (or timbers that meet the BAL requirements), etc. Just complying with the low-level rating can be quite onerous and expensive - I shudder to think what the high level ratings would require.

Thanks for this information. Appreciate it!

[bgilbert (Barry gilbert)]

. Can someone tell me the role of CO2 over the period of this plot

[gregbradley]

I have lived in Sydney most of my life.

I know for a fact because I have lived through it that Sydney is a much hotter city to live on than it was earlier on (55 years ago).

Sure its always been a hot city but in the 60 and 70's a hot day was 95-100F now its 114.

40C + now is a fairly common occurrence in Sydney whereas it was quite rare back then.

Bureau of Meterology keeps the statistics. Last 13 of the past 15 years have been the hottest and of course Penrith set a new record last week at an insane 48.9C.

To think man who now numbers close to 8 billion, can burn fossil fuels all day long, cut down the forests and not have a flashback from nature is naïve.

Arguing about graphs or "science" does not go anywhere. It seems science can be twisted easily much like accounting.

Man is a polluter. The Aborigines go back 60,000 years and no pollution. Wow. We could learn a thing or two from them.

When you pollute there are consequences. Perhaps slow to appear, but they are there, especially long term. Man has never been good at seeing long term consequences until they are too obvious too ignore.

Not trying to be political and the politicising of the debate is not helpful either.

Greg.

[Tropo-Bob (Bob)]

Originally Posted by bgilbert

. Can someone tell me the role of CO2 over the period of this plot


Attachment 254075

So when are we due for the next Glacial Maximum? I assume that U are in part refering to the the 3 parts of Milankovitch cyclicity?

From memory, I think the three cycles are to line up to create snowball Earth in some 400,000 years, but have not seen anything on when the next Ice Age would have been due in the normal course of natural events.

[bgilbert (Barry gilbert)]

. Well Bob, your guess is as good as mine, looking at the cycles we could slip into the next interglacial (cooling), tomorrow, or the next thousand years or so, the increased CO2 could save us by postponing it a tadd.
.

[Tropo-Bob (Bob)]

Originally Posted by bgilbert

. Well Bob, your guess is as good as mine, looking at the cycles we could slip into the next interglacial (cooling), tomorrow, or the next thousand years or so, the increased CO2 could save us by postponing it a tadd.
.
Attachment 254076

Yes, it is a complex issue.

The thing to keep in mind with those cycles though is that higher levels of CO2 will move the temperature above what would have been otherwise expected. There can be other disruptions/complications of course like volcanoes and changes in ocean currents.

My understanding is that it was observations of Venus and Mars that first drew attention to the role of CO2. Theoretical calculations, which used the assumption that air was simply air fell well short of the observed temperatures. From that, the penny dropped that higher levels of CO2 traps heat on those planets well beyond that of Earth’s atmosphere.

We humans have thrived in the last 10,000 because of a relatively steady climate. It may at some stage turn cool and that will be a whole new issue. There was a horrible suggestion that we could put beads in orbit and cool the planet through dispersing the Sun’s heat. What a nightmare that would be when the Earth hits a cooling phase.

However, the current problem is that we are seeing far more high-temperature records being broken than low-temperature records and put simply: That’s not good.

Just re rising Sea Levels, that a vexed issue as well. Some places are going under, but that is more related to the Earth crust rising and falling at different places and unfortunately, the scientific data on that is generally ignored in this most emotional of debates.

[bgilbert (Barry gilbert)]

. You're right Greg, Penrith was extremely hot but, it has only been keeping records since about 1995. Sydney's oldest recording station is Observatory Hill and has been recording since 1860, it only reached 35.9 on the same day that Penrith reached 48.9, its hottest jan. day on record is 45.8 deg. 2013, its hottest feb. day 42.1 deg in 1926. The capital cities are getting hotter, and country centres are showing a slight mean temp. increase and a slight max temp. decrease. Walgett's hottest day on record was 49.2 deg. 1903. all this data is from BOM archives.

[Outcast (Carlton)]

Originally Posted by bgilbert

. You're right Greg, Penrith was extremely hot but, it has only been keeping records since about 1995. Sydney's oldest recording station is Observatory Hill and has been recording since 1860, it only reached 35.9 on the same day that Penrith reached 48.9, its hottest jan. day on record is 45.8 deg. 2013, its hottest feb. day 42.1 deg in 1926. The capital cities are getting hotter, and country centres are showing a slight mean temp. increase and a slight max temp. decrease. Walgett's hottest day on record was 49.2 deg. 1903. all this data is from BOM archives.

Historic temperatures, like a lot of of historic record keeping also needs to viewed in the context of how they were obtained. Methodology for temperature recording 100 years ago were not always as standardised as they are in latter days. It's been proven that a lot (note: a lot, not all) were recorded in direct sunlight or on thermometers hung in buildings that trapped heat. This is where people get on their high horse about historical data being adjusted and fuel the argument that it's all a hoax...

The geologic temperature record doesn't lie or present/support a particular agenda. It just is...

[Tropo-Bob (Bob)]

Originally Posted by Outcast

...

The geologic temperature record doesn't lie or present/support a particular agenda. It just is...

So true Carlton. However, few people understand how previous temperatures can be derived from Ice Cores. What they look for is the ratio of Oxygen 18 Isotopes compared with the usual, Oxygen with a molecular weight of 16. As a basic ingredient of water and then snow and thus ice, Oxygen 18 Isotopes need more energy/heat to evaporate from the oceans than Oxygen 16. It all relates to the Kinetic Energy equalling Mass x Velocity squared, meaning that the ratio O18 to O16 becomes higher as temperatures/available energy increases and less when temperatures are lower.

I hope that make sense.

[Peter Ward]

Originally Posted by gregbradley

Arguing about graphs or "science" does not go anywhere. It seems science can be twisted easily much like accounting.........

Greg.

The science is quite clear. Peer review does it's job well.

Yet despite ever increasing accuracy, climate science has been painted as a "pseudo" science by vested interests using bogus arguments that latch on to small variability's predicted results as being a reason to doubt the undeniable underlying science.

Lets' say someone called Jones says it's safe to jump off the sky deck on the 88th floor of Melbourne's Eureka Tower (sans parachute)

I dusted off my old Physics text (Resnick and Halliday) and plugged a few numbers into some of the equations: Newton's laws will come into effect.

A small wind gust (a non-Newtonian correction) may even slow your acceleration toward the pavement below. You might even able to measure that slight deceleration, by looking at accelerometer data from your i-phone as you go past the 50th floor.

Then declare Newton/everyone was wrong as "I'm slowing down!".

Yeah, nah.

Assuming a weight of say 85 kilograms, and the typical air resistance of a skydiver's kit, you will fall for 8.67 seconds. You will hit the pavement doing some 189.76 km/hr. Perhaps a little extra air drag did slow you to a paltry 189 km/hr. Your head will also sound and look like ruptured watermelon as you spatter across the pavement below.

Gravity will win every time.

Maybe your last thought was: bugger. Alan Jones lied to me!

Climate change was predicted decades ago and came about from three simple observations.

1) Prior to the industrial age, the earth's atmosphere was effectively in equlibrium
2) CO2 gas traps solar radiation (this observation won the first Nobel prize in Chemistry)
3) Human activities have been adding CO2 to the atmosphere since the start of the industrial age. (BTW, there is no natural mechanism for this increase, if you find it, write a paper and book your ticket to Stockholm for the 2021 Nobel prize and million dollar cheque)

So the hypothesis was: will adding more CO2 to the global atmosphere cause more heat to be trapped? The answer is simply: yes.

As to how much, plus the myriad of effects higher temperatures may bring,
that is open to debate. But terrible recent events would suggest climate science predictions may have been too conservative.

[Outcast (Carlton)]

Originally Posted by Tropo-Bob

So true Carlton. However, few people understand how previous temperatures can be derived from Ice Cores. What they look for is the ratio of Oxygen 18 Isotopes compared with the usual, Oxygen with a molecular weight of 16. As a basic ingredient of water and then snow and thus ice, Oxygen 18 Isotopes need more energy/heat to evaporate from the oceans than Oxygen 16. It all relates to the Kinetic Energy equalling Mass x Velocity squared, meaning that the ratio O18 to O16 becomes higher as temperatures/available energy increases and less when temperatures are lower.

I hope that make sense.

Yep, perfectly clear, cheers..

Thing is.. folk keep pulling out little cherries from a very complex equation to support their 'belief' when the entire body of evidence actually points somewhere else.. This I don't get.. I just don't... we have an environment that is extremely complex & the difference between sustaining life as we know it or not is, extremely fine... some things we influence, some we don't (well, not directly).. if we see where our influence is detrimental to that fine balance & we have the ability to modify our influence then.. why wouldn't you do that... ? Does that stop the changing of our environment.. possibly, possibly not.. but, geesh... let's not die out wondering what might have been...

I'm tired of people pointing to temperature records 'see, it was much hotter on this day in 1861', or milankovic cycles or some other vague factor which has an effect on our climate/environment but, are one, just one small part of the entire climate/environmental equation, or any other specific, wee little gem that supports their position...

Fact: Our climate is changing
Fact: The overall & underlying reasons our climate is changing are extremely complex, it's not just one thing or cycle.
Fact: Our behaviour is not helping in a manner that will improve our chances of survival..
Fact: We are knowingly increasing the levels of CO2 into our environment & at the same time reducing that part of our environment capable of soaking it up.
Fact: Excess CO2 in our atmosphere leads to mass extinction.. which is also clearly visible the Geological & Archeological record...
Fact: Our environmental record overall is atrocious
Fact: All of humanities activities are having a profound, negative effect on the environment & it's time we had a cold hard look at ourselves & our activities

We treat our world like a rubbish dump.. & without having a plan A, our plan B seems to be to find a habital planet somewhere else or terraform a planet in our own solar system... or you, know.. we could just try cleaning up our act & see how that works maybe..

Sorry Bob, not directed at you but, rant over...

I just get frustrated at people responding to very interesting threads by trying to dumb down a situation down to one, specifically chosen part of the overall equation...

[Retrograde (Pete)]

Clearly the wrong people are running the BOM, CSIRO and hell even NASA too as there seem to be people on the internet who know more about it than the people who currently run these institutions.

[pgc hunter]

Once upon a time, Iceinspace used to be about astronomy, not hourly respawning threads about politics and global warming. Shame this crap outweighs the observing reports by 1000:1 these days.

[bgilbert (Barry gilbert)]

. Peter Peter, calm down.
I think you should go and get your dusty old Resnick and Halliday, bin it, and get a copy of Halliday and Resnick and start reading it. Firstly I agree the planet is warming, the sea level plot I showed several posts ago shows that, I used it as a proxy for temperature rise.
. The question I asked was what role did CO2 play in that 150 metre sea level increase. Well it increased also, by a factor of 2. The big question is what made the CO2 increase it was thousands of years before the industrial revolution.
. The next plot I posted showed about 8 to ten such events over about 800 thousand years. What caused those? not humans burning coal.
. The other thing you might get out of Halliday and Resnick is the role that water vapour plays in the greenhouse effect. CO2 is a very narrow band absorber of infrared, 667 nm only. Water vapour is very broad band absorber, it also behaves differently when it is water droplets (some forms of cloud)or ice(other forms of cloud).
. Finally, when the sea temperature increases the dissolved CO2 comes out of solution into the atmosphere. This can be seen in ice core analysis and shows that CO2 increase lags temperature by as much as 800 years.
. By the way, the so called climate scientists with the IPCC are mostly computer modelers, and their predictions have been woefully in error.
. Sorry about the science but it all I've got