Climate Feedbacks and possible warming

[iguanaman]

Perhaps gradual warming over the last 44,000 years!
Nope the Study does not say warming but warmth, you and SA are implying warming where it was not mentioned!

The arctic has risen 5 degrees in the last 50 years and the rest of the earth will soon follow if we do not make massive decreases in our CO2 emissions in the next decade. The arctic is but a harbinger of what is to come.

 

[longview]

Here is the feedback loop I most recently became aware of (and that scares me)...
"As the planet gets warmer, sea level rises for two reasons. First, warmer temperatures cause ice on land like glaciers and ice sheets to melt, and the meltwater flows into the ocean to increase sea level. Second, warm water expands and takes up more space than colder water, increasing the volume of water in the sea." (my bolding)

Sea Level Rise

ocean.si.edu

Warmer high temperatures can cause glaciers to melt, on the low side of the average(where more than half of the warming is happening) the temperature still has to be above freezing for any melting to happen.
If we look at some of the long term tide gauges, we see that the rate of the rise, has been almost unchanged over the era of AGW.
New York, for example is slightly below the global satellite average rate, but going back 150 years,

 

[longview]

The arctic has risen 5 degrees in the last 50 years and the rest of the earth will soon follow if we do not make massive decreases in our CO2 emissions in the next decade. The arctic is but a harbinger of what is to come.

That is not what the predictions say, they expected greater warming in the higher latitudes.
James Hansen's 1997 paper had this drawing of expected warming, notice those large peaks at + and -60 degrees?

 

[mrjurrs]

Warmer high temperatures can cause glaciers to melt, on the low side of the average(where more than half of the warming is happening) the temperature still has to be above freezing for any melting to happen.
If we look at some of the long term tide gauges, we see that the rate of the rise, has been almost unchanged over the era of AGW.
New York, for example is slightly below the global satellite average rate, but going back 150 years,

Don't particularly give a crap about your charts and glacial melting. For whatever reason, glaciers are melting today. Do you deny that?

You didn't even try to address the loop I indicated most concerned me.

 

[longview]

Don't particularly give a crap about your charts and glacial melting. For whatever reason, glaciers are melting today. Do you deny that?

You didn't even try to address the loop I indicated most concerned me.

Why would I deny that the glaciers are melting, they have been melting for 12,000 years.
As for your concerns, the amount the sea level will respond to warming is predicated on the amount of actual warming.
If the climate feedback is low, then less warming equals less sea level rise.

 

[iguanaman]

Warmer high temperatures can cause glaciers to melt, on the low side of the average(where more than half of the warming is happening) the temperature still has to be above freezing for any melting to happen.
If we look at some of the long term tide gauges, we see that the rate of the rise, has been almost unchanged over the era of AGW.
New York, for example is slightly below the global satellite average rate, but going back 150 years,

New data suggest that the rate of sea level rise has more than doubled since the 1800's. It is far from linear.

Sea Level Rise Accelerating Faster Than Thought​

Sea level rise is a direct consequence of the warming of the planet from the accumulation of carbon dioxide and other greenhouse gases in the atmosphere. As those gases trap extra heat, the oceans mop up some of the excess; as water warms, it expands, meaning that as the oceans heat up, they rise. Warming also melts glacial ice currently trapped on land, adding to the ocean’s burden. Since the beginning of the 20th century, average global sea level has risen by 8 inches.

Estimates of sea level rise, particularly before about 1990, when satellites came into service, have relied on the records of tide gauges scattered unevenly around the world. From those records, scientists have estimated rates of 1.6 to 1.9 millimeters per year of global sea level rise for the 20th century.

For the past couple of decades, when satellites have been able to take more accurate measurements, the rate is estimated at about 3 millimeters per year. (Part of the reason for the acceleration is that it takes more heat to raise the temperature of water than air and more time is needed to transport that heat into the deep ocean.)

Hay didn’t actually set out to challenge these established estimates of sea level rise. She and her team were hoping to find the telltale signatures of glacier melt in tide gauge records, using statistical methods that hadn’t been applied to the issue of sea level rise before. They figured out that they could use those same methods to estimate global sea level rise. When they tried it, they realized “that we didn’t get the same thing” as the established estimates, Hay said.

Instead, their range was lower, from 1.0 to 1.4 millimeters per year from 1901 to 1990.

https://www.climatecentral.org/news/sea-level-rise-accelerating-18543

 

[mrjurrs]

Why would I deny that the glaciers are melting, they have been melting for 12,000 years.
As for your concerns, the amount the sea level will respond to warming is predicated on the amount of actual warming.
If the climate feedback is low, then less warming equals less sea level rise.

 

[iguanaman]

That is not what the predictions say, they expected greater warming in the higher latitudes.
James Hansen's 1997 paper had this drawing of expected warming, notice those large peaks at + and -60 degrees?
View attachment 67361334

The north and south poles play a vital role in regulating the Earth’s climate — acting as our cooling system. Reduced snow cover will mean that the Earth absorbs more heat from the sun and ocean currents shift. The Arctic Ocean, a mixture of fresh melt water and seawater, influences ocean currents around the globe. Some scientists believe that too much fresh melt water could actually 'switch off ' some of these sea currents, which play a crucial role in the climate further south.
https://www.eea.europa.eu/signals/signals-2010/arctic

The weakening of the gulf stream is already evident and will have profound impact on your climate in the U.K. Be afraid very afraid.

Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points.
The research found “an almost complete loss of stability over the last century” of the currents that researchers call the Atlantic meridional overturning circulation (AMOC). The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.
Such an event would have catastrophic consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America and West Africa; increasing storms and lowering temperatures in Europe; and pushing up the sea level off eastern North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets.

https://www.theguardian.com/environ...ts-spot-warning-signs-of-gulf-stream-collapse

 

[longview]

Sea Level Rise Accelerating Faster Than Thought​

Sea level rise is a direct consequence of the warming of the planet from the accumulation of carbon dioxide and other greenhouse gases in the atmosphere. As those gases trap extra heat, the oceans mop up some of the excess; as water warms, it expands, meaning that as the oceans heat up, they rise. Warming also melts glacial ice currently trapped on land, adding to the ocean’s burden. Since the beginning of the 20th century, average global sea level has risen by 8 inches.

Estimates of sea level rise, particularly before about 1990, when satellites came into service, have relied on the records of tide gauges scattered unevenly around the world. From those records, scientists have estimated rates of 1.6 to 1.9 millimeters per year of global sea level rise for the 20th century.

For the past couple of decades, when satellites have been able to take more accurate measurements, the rate is estimated at about 3 millimeters per year. (Part of the reason for the acceleration is that it takes more heat to raise the temperature of water than air and more time is needed to transport that heat into the deep ocean.)

Hay didn’t actually set out to challenge these established estimates of sea level rise. She and her team were hoping to find the telltale signatures of glacier melt in tide gauge records, using statistical methods that hadn’t been applied to the issue of sea level rise before. They figured out that they could use those same methods to estimate global sea level rise. When they tried it, they realized “that we didn’t get the same thing” as the established estimates, Hay said.

Instead, their range was lower, from 1.0 to 1.4 millimeters per year from 1901 to 1990.

https://www.climatecentral.org/news/sea-level-rise-accelerating-18543

Yep, that is what Church and White found, but there are plenty of those tide gauges that show rates of sea level rise higher than 1.0 to 1.4 mm per year between 1901 and 1990.
NOAA sea level trends table

 

[longview]

Yep the average temperature is increasing, I never said it was not, and as expected the ocean will follow the air temperature.

 

[longview]

The north and south poles play a vital role in regulating the Earth’s climate — acting as our cooling system. Reduced snow cover will mean that the Earth absorbs more heat from the sun and ocean currents shift. The Arctic Ocean, a mixture of fresh melt water and seawater, influences ocean currents around the globe. Some scientists believe that too much fresh melt water could actually 'switch off ' some of these sea currents, which play a crucial role in the climate further south.

The weakening of the gulf stream is already evident and will have profound impact on your climate in the U.K. Be afraid very afraid.

Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points.
The research found “an almost complete loss of stability over the last century” of the currents that researchers call the Atlantic meridional overturning circulation (AMOC). The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.
Such an event would have catastrophic consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America and West Africa; increasing storms and lowering temperatures in Europe; and pushing up the sea level off eastern North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets.

https://www.theguardian.com/environ...ts-spot-warning-signs-of-gulf-stream-collapse

Again, greater warming at the high latitudes is predicted, the only real thing odd, is the lack of warming at the south pole.
Here is a comparison of the predicted warming by latitude vs the observed warming from NASA's GISS (That Hansen was the director of)

notice anything different between the predicted and the observed warming?

 

[mrjurrs]

Yep the average temperature is increasing, I never said it was not, and as expected the ocean will follow the air temperature.

And the feedback loop for sea level rise based on the larger volume of warm than cold water? I didn't claim you said that, I will say that imo, you deflect the outcomes to talk about the causes.

 

[longview]

And the feedback loop for sea level rise based on the larger volume of warm than cold water? I didn't claim you said that, I will say that imo, you deflect the outcomes to talk about the causes.

The sea levels are raising globally, although it is questionable if the rate of the rise has changed.
Satellites in theory could provide a better answer, but their accuracy is such that they would only see a minimum unit change once a decade.
TOPEX/Poseidon

Measurement​	Required accuracy​	Achieved accuracy​
Altimeter​	4.0 cm​	3.2 cm​
Satellite position​	12.8 cm​	2.8 cm​
SSH (Sea Surface Height)​	13.4 cm​	4.3 cm​

So if the stated rise is 3.3 mm per year, and the achieved accuracy is 32 mm, it would take ~ a decade of the sea level rising at that rate for a single minimum unit of change.
The far greater error is the correction for tide phase, the satellites must correct for the tide, but we do not have tide gauges everywhere, so they correct for the astronomical tide.
If you have spent any time reading the tides for fishing or boating, you know that the astronomical tide is almost always in error because of local conditions.
Honolulu, HI - Station ID: 1612340

I picked Hawaii, because it is in the middle of the Ocean, but as you can see there is a difference of .22 feet between the predicted tide and the observed tide.
I think that is an error of 67 mm.

 

[code1211]

LOL Try 44,000 years. For someone with the screen name "longview: you seem to have been born yesterday.

Arctic Warming Unprecedented in Last 44,000 Years​

Moss and other indicators suggest the current Arctic meltdown is unique in recent geologic history

Scientists have long known that the Arctic is warming faster than the rest of the globe, even as they had less of a grasp of how recent trends compare to thousands of years ago.
Now, a new study aims to fill the knowledge gap by concluding that recent summer warming in the eastern Canadian Arctic is unprecedented in more than 44,000 years. Prior research documented melt and temperature dynamics going back about 2,000 to 4,000 years in comparison, said study lead author Gifford Miller, associate director of the Institute of Arctic and Alpine Research at the University of Colorado, Boulder.

https://www.scientificamerican.com/article/arctic-warming-unprecedented-in-last-44000-years/

Of all of the interglacials over the last half million or so years, this one seems to be the coolest one. Given the fact that we have Jack Nicholson, this is to be expected.

<snip>


Palaeotemperature graphs compressed together.
<snip>

Considering the last 500 million or so years, we are STILL comparatively cool.

Just a pretty sustained period about 300 million years ago departs from the relatively warmer times than now.

How can anyone seriously assert that Anthropogenic CO2 Emissions are the PRIMARY cause of climate change?

 

[iguanaman]

Of all of the interglacials over the last half million or so years, this one seems to be the coolest one. Given the fact that we have Jack Nicholson, this is to be expected.

<snip>


Palaeotemperature graphs compressed together.
<snip>

Considering the last 500 million or so years, we are STILL comparatively cool.

Just a pretty sustained period about 300 million years ago departs from the relatively warmer times than now.

How can anyone seriously assert that Anthropogenic CO2 Emissions are the PRIMARY cause of climate change?

LOL So you jut ignore those red dots on the right of that chart? If anything shows the astonishing rapidity of the CO2 forcing it is that chart.

 

[longview]

LOL So you jut ignore those red dots on the right of that chart? If anything shows the astonishing rapidity of the CO2 forcing it is that chart.

Are not the last two red dots predictions, not observations?

 

[iguanaman]

Are not the last two red dots predictions, not observations?

The last blue line is over half way to the 2050 prediction already. It may be too low.

 

[longview]

The last blue line is over half way to the 2050 prediction already. It may be too low.

So you cannot even acknowledge that the last two dots are actually predictions of where the CO2 level might be in the future.

 

[iguanaman]

So you cannot even acknowledge that the last two dots are actually predictions of where the CO2 level might be in the future.

They are predictions in the rise of average temperature and are based on the best science available. You don't like science because you do not believe they can see the future. That is the entire purpose of climate science and you cannot deny that they have been right so far. The earth is warming at unprecedented rates and there is no other viable explanation but greenhouse gases despite vast efforts to prove otherwise.

 

[longview]

They are predictions in the rise of average temperature and are based on the best science available. You don't like science because you do not believe they can see the future. That is the entire purpose of climate science and you cannot deny that they have been right so far. The earth is warming at unprecedented rates and there is no other viable explanation but greenhouse gases despite vast efforts to prove otherwise.

You are entirely wrong, I love and respect Science, Been doing it my entire Adult life.
The predictions are often based on scenarios, like RCP8.5, which is listed as a business as usual.
RCP8.5 is a joke, and likely is impossible, as it calls for a CO2 level in year 2100 of 1370 ppm.
Since 1880, the CO2 level has increased 135 ppm from 280 ppm to 415 ppm, a level of 1370 ppm,
would require (1370 - 415)/79 = 12.088 ppm per year.
For reference the growth in the CO2 level since year 2000, is between 2 and 3 ppm per year, not 12 ppm per year!
Have the prediction of climate science been right so far? if they were we should be at about 2.25C of warming at this stage,
to be lined up for 2XCO2 warming of 3C, but the observed warming is 1.09C per the IPCC AR6.
NOAA AGGI tells us the 2011 forcing for all the greenhouse gasses in CO2-eq, and they represent ~75% of the total forcing,
and recent peer reviewed show that maximum warming from an emissions is reached in about 10 years,
Maximum warming occurs about one decade after a carbon dioxide emission
so all of the equalization warming from 2011, should already be present.

 

[Lord of Planar]

They are predictions in the rise of average temperature and are based on the best science available.

I would alter that statement to: "They are predictions in the rise of average temperature and are based on the science presented"

That is the entire purpose of climate science and you cannot deny that they have been right so far.

They have been far from right. The earth has already been in a trend for warming, naturally. As long as the ignore the full extent of many of the pertinent variables, nobody in their right mind should trust a single thing they say.

The earth is warming at unprecedented rates and there is no other viable explanation but greenhouse gases despite vast efforts to prove otherwise.

Why is it "unprecedented?" Because some activist said so?

 

[code1211]

LOL So you jut ignore those red dots on the right of that chart? If anything shows the astonishing rapidity of the CO2 forcing it is that chart.

ALL of the historical data on the chart is derived from proxy measurements.

The red dots on the right are projections that are oddly disconnected from the historical temperature ranges.

The lowest temperature PREDICTION from the red dots is a full 5 degrees above the temperature of 1880.

C'mon, man!

That said, though, EVEN IF we reached that unreachable level over the next 30 years, that would only put us into the range of the previous temperature peaks of the last four interglacials.

This warming is not excessive, not unprecedented and not unusual.