Heat watch

[BritDownUnder]

Research on records from tidal gauges in the UK indicates a rise of about 1mm per year in sea levels since about 1900. Looking deeper into it the data there are a lot of differences in different tidal gauges around the UK due to the fact that the land in North-Western Britain is still rising (post glacial rebound) and South-Eastern Britain is sinking.

Maybe a 60mm rise in the tide mark in ones lifetime is just not very discernible on your beach visits but the people of certain Pacific islands and Bangladesh are beginning to notice. The UK could probably adapt - personally if I was in government I would put tidal barrages across the Thames, Wash and Humber estuaries both to generate electricity and protect against high tidal surges.

I think a lot of what did in the Greenland Vikings was soil erosion, and their refusal to make friends with the locals (actually they were the locals when they arrived as no-one else was there but Inuit began to move in to their area from further North just before the Vikings died out). Apparently the Greenland ice cap is losing billions of tonnes of ice as meltwater per year but how much more land is being exposed and how useful it is to agriculture is anyone's guess.

[Default0ptions]

One thing that I certainly agree with in your post BDU is the real need to adapt rather than sit back and let your coastal cities get swamped.

But how soon might they be swamped?

Not immediately for continental shelf areas.

Someone brought up ‘rising sea levels’ and islands.

So;

On low level volcanic islands - they subside gradually over time. No climate change needed.

“Strange as it seems to us continent dwellers, it’s true. The world’s volcanic ocean islands are sinking“

http://oceans.mit.edu/news/featured-sto ... arwin.html

[Ralphw2]

Sea level rise is still in the early days, the slow rise over the last century is due mainly to the expansion of the waters of the oceans directly as they warm. This is only by a degree or so, and only in the top few metres of the water due to the curious property of water of reaching maximum density at 4C, so there is very little mixing with the deep oceans. Future sea level rise will be dominated by the melting of glacial ice , mostly from Greenland and Antarctica, as the offshore iceshelves melt and disperse, allowing the glaciers to flow faster towards the sea. Melting of the arctic sea ice does not by itself add to global sea levels, as the ice is already floating on water.

There are a lot of possible positive feedback mechanisms that could accelerate the melting of glaciers. Dust and soot landing on the top of the ice increases the absorbsion of solar radiation , and as the ice melts, the meltwater sinks into the body of the ice, leaving the soot on the surface of the ice to continue the melting. The meltwater sinks to the botton of the glacier where it lubricates the flow of the ice over the rocks beneath, Which exact methods will dominate are still being researched.

The arctic sea ice melt did seem to be accelerating a decade ago, and I reported it at length on this forum. This was in contrast to the antarctic ice which seemed stable to slightly rising. Since then, the rate of melt in the arctic seems to have slowed, although the ice remains dramatically thinner than it was 30 years ago. However, in the last few years, ice melt in the antarctic has been dramatically high, and is ringing alarm bells in scientists, because the long term sea level rise risk from antarctica is ten times larger than that from greenland, just because there is so much more ice there.

In summary, sea level rise is the slowest but most overwhelming and irreversible aspect of climate heating. Billions of people and by definition every major port in the world are within a few metres of sea level and a one metre rise would be catastrophic. Of course, by then, we will have already met many other catastrophies, and not so many people will be left to cope with them

[clv101]

Maslowski has always been an outspoken radical who did not reflect the scientific concensus. See the IPPC synthesis for the scientific understanding of sea ice, ice-free summers were *not* expected by 2013.

[Default0ptions]

Interesting stuff there Ralph. Thank you.

[BritDownUnder]

Water has the curious property of the solid form (most common solid form maybe), ice is less dense than the liquid. Otherwise the oceans would have ice at the bottom of them. Instead they have 4C water at the bottom of them. Not sure on the effect of salinity on all this.

[Ralphw2]

This paper is authored by a group including Hansen, so some people may dismiss it out of hand.

https://pubs.giss.nasa.gov/abs/ha09020b.html

In 2020 global shipping regulations reduced the permitted level of sulphur in bunker oil by 90%. This sharply reduced the global emissions of sulphur by about 10% overnight, and over the oceans by about 80%. Sulpher is a particulate pollutant that increases the formation of clouds, and the impact is particularly high over the oceans where the sun heats the ocean surface and vapourises the water. The aerosol effect increases the quantity of white, reflective clouds and causes an net cooling to counterbalance the warming effect of CO2. Sulpher is washed out of the atmosphere very quickly, in a matter of days or weeks, so this sudden drop in emisions provided a step change that scientists could monitor to estimate how big the aerosol cooling effect is, as the current IPCC model had high uncertainty over this figure, anything from 0.2C to 0.9C of additional warming being masked.

The paper reports that the change in total energy balance over the southern oceans was much larger than anticipated, and calculated that human sulpher emissions have masked far more heating than previously estimated. The change in 2020 coincided with 3 years of La Nina weather patterns, which masked the step change, but this year saw the first part of a 2 year El Nino cycle, and is showing dramatically more heat going into the oceans, and also dramatically higher global temperatures. The net result is that the climate sensitivity to CO2 (and other greenhouse gases) is 40-60% higher than previously calculated. As the oceans have very high heat capacity, it will take years for the heat imbalance to settle, and for the full impact of this step change to be seen .

Global emissions of sulpher continue to fall as countries like China clean up their coal power stations with scrubber units, and global consumption of coal imust fall dramatically if we are to limit CO2 based heating

Basically we are damned if we do, and damned if we dont

[Ralphw2]

To the surprise of no one, February was the warmest on record in the UK. Also very wet. It is raining heavily again today.

[UndercoverElephant]

To the surprise of no one, February was the warmest on record in the UK. Also very wet. It is raining heavily again today.

Given the current long term weather forecast, it now looks likely that the last ground frost this winter, at least where we are, was in January. A lot of the wildlife is at least 2 weeks ahead of where it usually is. Our ponds are already full of hatched frog tadpoles in vast numbers, for example. Usually if the frogs spawn as early as they did this year then most of them die an icy death.

[BritDownUnder]

I seem to remember the dirty power station emissions in the 1970s were thought to have caused the terrible droughts in the Sahel region culminating in the 1984 Ethiopia famine.

[clv101]

To the surprise of no one, February was the warmest on record in the UK. Also very wet. It is raining heavily again today.

Given the current long term weather forecast, it now looks likely that the last ground frost this winter, at least where we are, was in January. A lot of the wildlife is at least 2 weeks ahead of where it usually is. Our ponds are already full of hatched frog tadpoles in vast numbers, for example. Usually if the frogs spawn as early as they did this year then most of them die an icy death.

We had frost 2nd and 3rd March!

[northernmonkey]

We've had ground frost more or less constantly for the last two weeks at 5:30am each morning (when I set off for work)

[UndercoverElephant]

To the surprise of no one, February was the warmest on record in the UK. Also very wet. It is raining heavily again today.

Given the current long term weather forecast, it now looks likely that the last ground frost this winter, at least where we are, was in January. A lot of the wildlife is at least 2 weeks ahead of where it usually is. Our ponds are already full of hatched frog tadpoles in vast numbers, for example. Usually if the frogs spawn as early as they did this year then most of them die an icy death.

We had frost 2nd and 3rd March!

You are further inland than us, which probably makes a significant difference. We can see hills in the distance which keep their snow/ice/frost long after ours has gone.

[Catweazle]

My seedlings have been bitten by frosts in May before. This year I have built insulated benches in my polytunnel, they have 25mm polystyrene base, a film heating element usually used for underfloor heating, ceramic tiles and the covered propagator / seed trays on top. The heating element is controlled by an Inkbird thermostat, currently set to 20c it has germinated tomatoes, peppers, peas, beans, cucumbers, some herbs etc. later on the temp will be turned down to act as frost protection.

[adam2]

March was the "hottest ever" in the UK, the latest in a long run of new records, fears are growing that climate change is accelerating.
https://www.bbc.co.uk/news/science-environment-68665166