Havniveau stigninger - hvad mener forskningen?

Der findes meget lidt forskning, der finder menneskets påvirkning "minimal".
Udover nogle få, der står tæt på Trump, der som bekendt ikke kan sige en sammenhængende sætning uden den indeholder junk news.

Du glemmer systematisk at forskerne (herunder IPCC) har en stor interesse i at blæse alarm. Derfor skal man tage alt hvad de sige med største forbehold.

delphi skrev:
Hvis man sammenligner med denne reelle meget meget minimale afsmeltning af is fra indlandsisen



og prøver at tænke på hvilken afsmeltningshastighed indlandsisen har været udsat for under middelalderen hvor landbrugsdriften på Grønland var af samme art som den vi i dag praktiserer på vore breddegrader. Eller afsmeltningen dengang har været mange gange det vi ser i dag på Grønland..

The analysis indicates that the rate of 20th century retreat of the Kulusuk glaciers was greater than during any other century of the past 1.3 ka, including during the Medieval Climate Anomaly.

Furthermore, the 20th century retreat rate was 2–3 times the rate of any other period of retreat during the past 4.1 ka, and almost twice as rapid as the early Holocene retreat that marked the transition into the regional HTM (Fig. 6).

This comparison helps to place the rate of 20th century glacier loss in the context of natural episodes of past glacier activity

This latest report was authored by 104 climate scientists from 36 countries and reflecting findings in 6,981 studies. It contains a wealth of information but some of the key points can be summarized as follows:

Sea-level rise is accelerating because the Greenland and Antarctic ice sheets are melting at an increasing rate;
The oceans, while still basic, are becoming more acidic, which will have serious consequences for coral reefs and shell-building marine species;
The oceans are warming rapidly, leading to more frequent marine heatwaves, which also damage coral reefs;
Researchers are beginning to see more of the most intense hurricanes, those in Category 4 and 5, which in combination with higher sea levels and increased precipitation pose increasing risks and damages to coastlines;
Melting of permafrost could become a major feedback, adding carbon emissions and global warming in energy scenarios with significant continued fossil fuel burning;
Ocean oxygen levels are declining, which in combination with rising temperatures drives marine species away from the equator toward the poles, and, in concert with algal blooms, could lead to reduced seafood catches at fisheries.

delphi skrev:
De 700 øverste meter af oceanerne indeholde 250 mio. km3 vand.

200 Zetta Joule er det samme som 55.555.555.555.555 MWh. som kan varme 250 Km3 0,19 grad.

De 700 M øverste vandmasser i oceanerne er altså varmet 0,19 grad over de sidste 40 år. Eller vandmasserne er i det store og hele ikke varmet.

delphi: og havvandstigningerne er på ingen måde accellererende

delphi skrev:
PÅ 60 år er udviklingen mere eller mindre konstant og havniveauet er steget 15 cm.



Og selv om over 60 % af den menneskeskabte co2 er afsæt i atmosfæren over de sidste 30 år år udviser havvandsstigningerne ingen acceleration, over denne periode!!

Jesper-Midtfyn skrev:
Med hensyn til accelerationen i havstigningerne kan man tage et kig på en af de grafer, som en af de toneangivende forskere John Englander præsenterer.

It is virtually certain that global mean sea level rise will con- tinue beyond 2100, with sea level rise due to thermal expan- sion to continue for many centuries. The amount of longer term sea level rise depends on future emissions. The few available process-based models that go beyond 2100 indicate global mean sea level rise above the pre-industrial level to be less than 1 m by 2300 for greenhouse gas concentrations that peak and decline and remain below 500 ppm CO2-eq, as in scenario RCP2.6. For a radiative forcing that corresponds to above 700 ppm CO2-eq but below 1500 ppm, as in the scenario RCP8.5, the projected rise is 1 m to more than 3 m
(medium con dence). This assessment is based on medium con dence in the modelled contribution from thermal expansion and low con- dence in the modelled contribution from ice sheets. The amount of ocean thermal expansion increases with global warming (0.2 to 0.6 m °C–1) but the rate of the glacier contribution decreases over time as their volume (currently 0.41 m sea level equivalent) decreases. Sea level rise of several meters could result from long-term mass loss by ice sheets (consistent with paleo data observations of higher sea levels during periods of warmer temperatures), but there is low con dence in these projections. Sea level rise of 1 to 3 m per degree of warming is projected if the warming is sustained for several millennia (low con - dence). {13.5.4, Figures 13.4.3, 13.4.4}
The available evidence indicates that sustained global warming greater than a certain threshold above pre-industrial would lead to the near-complete loss of the Greenland ice sheet over a mil- lennium or more, causing a global mean sea level rise of about 7 m. Studies with xed ice-sheet topography indicate the threshold is greater than 2°C but less than 4°C (medium con dence) of global mean surface temperature rise with respect to pre-industrial. The one study with a dynamical ice sheet suggests the threshold is greater than about 1°C (low con dence) global mean warming with respect to pre-industrial. We are unable to quantify a likely range. Whether or not a decrease in the Greenland ice sheet mass loss is irreversible depends on the duration and degree of exceedance of the threshold. Abrupt and irreversible ice loss from a potential instability of marine-based sectors of the Antarctic ice sheet in response to climate forcing is possible, but current evidence and understanding is insuf cient to make a quantita- tive assessment. {5.8, 13.3, 13.4 }
Regional Sea Level Change Projections
It is very likely that in the 21st century and beyond, sea level change will have a strong regional pattern, with some places experiencing signi cant deviations of local and regional sea level change from the global mean change. Over decadal periods, the rates of regional sea level change as a result of climate variability can differ from the global average rate by more than 100% of the global average rate. By the end of the 21st century, it is very likely that over about 95% of the world ocean, regional sea level rise will be positive, and most regions that will experience a sea level fall are located near current and former glaciers and ice sheets. About 70% of the global coastlines are projected to experience a relative sea level change within 20% of the global mean sea level change. {13.6.5, Fig- ures 13.18 to 13.22}
Projections of 21st Century Sea Level Extremes and Surface Waves
It is very likely that there will be a signi cant increase in the occurrence of future sea level extremes in some regions by 2100, with a likely increase in the early 21st century. This increase will primarily be the result of an increase in mean sea level (high con - dence), with the frequency of a particular sea level extreme increasing by an order of magnitude or more in some regions by the end of the 21st century. There is low con dence in region-speci c projections of storminess and associated storm surges. {13.7.2, Figure 13.25}

Jesper-Midtfyn skrev:
Ja, der er desværre risiko for store problemer især i de asiatiske storbyer som Bangkok og Jakarta og lande som Bangladesh i løbet af de næste 30 år. Det er ikke bare havstigninger men også landsænkninger, der spiller ind.

Graf for Fort Phrachula.

Klimatis skrev:

Jesper-Midtfyn skrev:
Ja, der er desværre risiko for store problemer især i de asiatiske storbyer som Bangkok og Jakarta og lande som Bangladesh i løbet af de næste 30 år. Det er ikke bare havstigninger men også landsænkninger, der spiller ind.

Graf for Fort Phrachula.

Ovenstående alarmisme debunked af Tony Heller

https://www.youtube.com/watch?v=wjFAsxY9-0M

Climate change will put pressure on cities in multiple ways, said Loretta Hieber Girardet, a Bangkok resident and United Nations disaster risk-reduction official. Even as global warming floods more places, it will also push poor farmers off the land to seek work in cities.

"It is a dire formula," she said.

But coastal erosion and more frequent storms mean the city needs to bolster its flood defences. Among the engineering measures that might do so, said Suttisak Soralump, an associate professor at Bangkok's Kasetsart University, would be elevating a highway that runs along the coast to serve as a dike.

"In Thailand, we have engineers and we have our knowledge," he said. "We are not going to let the Grand Palace sink — there's no way."

I øvrigt er der mange gode fremstillinger af de landsænkninger, som er i Asien, og som gør udfordringerne i forhold til havstigninger betydelig mere markant.

Peter Villadsen skrev:

Klimatis skrev:

Jesper-Midtfyn skrev:
Ja, der er desværre risiko for store problemer især i de asiatiske storbyer som Bangkok og Jakarta og lande som Bangladesh i løbet af de næste 30 år. Det er ikke bare havstigninger men også landsænkninger, der spiller ind.

Graf for Fort Phrachula.

Ovenstående alarmisme debunked af Tony Heller

https://www.youtube.com/watch?v=wjFAsxY9-0M

Hvordan kan en person med tilknytning til Heartland Institute, der har et forfærdeligt renome, debunke noget som helst?

Lyt til forskningen og bliv klogere...

Jørgen Petersen skrev:
Peter Villadsen tænker ikke selvstændigt. Han gengiver blot de mest alarmistiske budskaber, som han kan finde.

Klimatis skrev:

Peter Villadsen skrev:

Klimatis skrev:

Jesper-Midtfyn skrev:
Ja, der er desværre risiko for store problemer især i de asiatiske storbyer som Bangkok og Jakarta og lande som Bangladesh i løbet af de næste 30 år. Det er ikke bare havstigninger men også landsænkninger, der spiller ind.

Graf for Fort Phrachula.

Ovenstående alarmisme debunked af Tony Heller

https://www.youtube.com/watch?v=wjFAsxY9-0M

Hvordan kan en person med tilknytning til Heartland Institute, der har et forfærdeligt renome, debunke noget som helst?

Lyt til forskningen og bliv klogere...

Forfærdeligt renomé hos dommedagsprofeter - så er man vist et hædersmenneske.

Men bort set fra det - Hvad med at holde dig til argumenterne i stedet for at prøve at sværte et andet menneske.

Prøv at imødegå hans argumenter og fakta.

Tænk selv og bliv klogere

Peter Villadsen skrev:

Klimatis skrev:

Peter Villadsen skrev:

Klimatis skrev:

Jesper-Midtfyn skrev:
Ja, der er desværre risiko for store problemer især i de asiatiske storbyer som Bangkok og Jakarta og lande som Bangladesh i løbet af de næste 30 år. Det er ikke bare havstigninger men også landsænkninger, der spiller ind.

Graf for Fort Phrachula.

Ovenstående alarmisme debunked af Tony Heller

https://www.youtube.com/watch?v=wjFAsxY9-0M

Hvordan kan en person med tilknytning til Heartland Institute, der har et forfærdeligt renome, debunke noget som helst?

Lyt til forskningen og bliv klogere...

Forfærdeligt renomé hos dommedagsprofeter - så er man vist et hædersmenneske.

Men bort set fra det - Hvad med at holde dig til argumenterne i stedet for at prøve at sværte et andet menneske.

Prøv at imødegå hans argumenter og fakta.

Tænk selv og bliv klogere

søger viden hos dem, der besidder den,
Og nej, jeg spilder ikke tid på Tiny Heller, men lytter til forskningen.

Der er en klar og tydelig opfordring til at reducere vores udledninger.
Læs selv studierne, der jævnligt udgives.

Så skal jeg hjælpe dig.

Tony Heller viser at tide gauge på Fort Phrachula er placeret i Chayo Prayas floddelta som meget "overaskende synker" og dermed viser en meget stor "havvandstigning". Tæt ved på kalkstensøen Koh Si Chang er der også en tide gauge som viser en meget lille havvandsstigning (ca. 1 mm/år), men den bliver der selvfølgelig ikke refereret til hos Climate Central da den ikke passer ind i dommedagsscenariet produceret til at skræmme folk.

Der er igangsat en storstillet smædekampagne mod Tony Heller på internettet. Der er sågar oprettet en fake Tony Heller hjemmeside. Det er det sædvanlige mønster smædekampagne, tilsværtning og intimidering fra alarmisternes side når de mangler argumenter. Det er selvfølgelig også synd for alarmisterne at de endnu ikke kan justere nyhedsarkiver som de historiske temperaturmålinger bliver. Tony Heller er farlig for deres dommedagsscenario derfor den voldsomme hadske reaktion. Du gider ikke beskæftige dig med Tony Heller - det er dit valg, men trist du ikke har et åbent sind. Jeg ved godt det kan gøre ondt i sjælen når virkeligheden ikke passer med sin religiøse overbevisning.

Most estimates of global mean sea-level rise this century fall below 2 m. This quantity is comparable to the positive vertical bias of the principle digital elevation model (DEM) used to assess global and national population exposures to extreme coastal water levels, NASA's SRTM. CoastalDEM is a new DEM utilizing neural networks to reduce SRTM error. Here we show – employing CoastalDEM—that 190 M people (150–250 M, 90% CI) currently occupy global land below projected high tide lines for 2100 under low carbon emissions, up from 110 M today, for a median increase of 80 M. These figures triple SRTM-based values. Under high emissions, CoastalDEM indicates up to 630 M people live on land below projected annual flood levels for 2100, and up to 340 M for mid-century, versus roughly 250 M at present. We estimate one billion people now occupy land less than 10 m above current high tide lines, including 250 M below 1 m.