Hacker News Reader

Comment by chrisco255 | Hacker News Reader

Meanwhile Antarctic sea ice has trended up over the past 5 decades: https://nsidc.org/data/seaice_index/

Sea ice volume is above 2012 in the Arctic: http://polarportal.dk/en/sea-ice-and-icebergs/sea-ice-thickn...

And Greenland has had massive, earlier than usual gains in ice this year (growth started in August, weeks earlier than usual): http://polarportal.dk/en/greenland/surface-conditions/

Cheyenne, WY saw record breaking cold this past week, reaching 2 degrees Fahrenheit in October, breaking the 1873 October record of 5 degrees Fahrenheit: https://www.wyomingnews.com/news/local_news/cheyenne-sees-as...

Northern Hemisphere snow mass is nearly 400 Gigatons above average for this time of year: https://globalcryospherewatch.org/state_of_cryo/snow/fmi_swe...

View on HN

> Meanwhile Antarctic sea ice has trended up over the past 5 decades

https://nsidc.org/cryosphere/seaice/characteristics/differen...

The Antarctic is a physical land mass. The Antarctic sea ice always melts away during the spring/summer. The Antarctic is surrounded by ocean, making precipitation an often occurrence, which funnily enough means that it snows more on the land when ocean temperatures rise slightly, and this snow helps build the seasonal ice around the Antarctic.

In contrast, the Arctic isn't a land mass, it's only ice, and it's mostly surrounded by land, making precipitation a less often occurrence and making the effects of rising ocean temperatures more devastating.

Basically, there's no going back once the Arctic melts, and by the time we see the Antarctic ice receding we'll be in serious trouble.

> Sea ice volume is above 2012 in the Arctic

2012 was an outlier, but sure.

> And Greenland has had massive, earlier than usual gains in ice this year

See the explanation for landmasses above.

> Cheyenne, WY saw record breaking cold this past week > Northern Hemisphere snow mass is nearly 400 Gigatons above average for this time of year

Climate change will have variable effects on local weather around the world. An upward trend in global average temperature doesn't mean everywhere is going to get hotter all the time.

This was predicted back in the 90s - the poles are so far below freezing that warmer temperatures increase polar snowfall (since they increase evaporation but remain cold enough for snow to form).

I don't think we predicted the Arctic ice disappearing this fast, though.

But doesn't arctic ice all be floating in sea water mean it has no effect on sea levels? Why "there is no going back"? Since it has been ice free in the past and then ice came back, why shouldn't it happen again?

https://nsidc.org/news/newsroom/20050801_floatingice.html

Salt water is denser than fresh water. The displacement of the Arctic ice is less than the displacement of the water contained in that ice when it melts. So the sea levels will rise. Though, that's not the only problem...

Think of the Arctic as exactly what it is, a giant ice cube, keeping your drink (or, you know, the world) cool. The smaller the ice cube gets, the smaller its effect on keeping your drink cool. When it's gone, your drink quickly goes to room temperature. It's highly unlikely that we can survive like we currently do without the Arctic. Sure, the ice might come back in 10 000 years or so, not particularly useful to us in the short term though, is it?

And the problem isn't that the Earth goes through natural cycles of cooling and warming, it's that our actions are accelerating the warming of the Earth, meaning we've got even less time to figure out how we as a species would survive the natural heating of the Earth.

Thermal expansion of the oceans will contribute significantly to sea level rise. That is, until that is dwarfed by Greenland melting, followed by Antarctica.

Generally speaking climate change generally is considered to include increased occurrence of severe events.

It's also La Niña this year, so the northern US will see a wetter, colder winter while the southwest will be warmer and drier.

> Sea ice volume is above 2012 in the Arctic:

2012 was the lowest minimum ever, and 2020's minimum only slightly above it. For many days 2020 was lower than 2012 on the corresponding days, and now we are into an uncharted territory of the latest refreeze ever.

Here's a graphic so you can see it in context:

https://twitter.com/ZLabe/status/1318913839568662529?s=19

Do you believe there are higher than normal levels of carbon present in the atmosphere that are the direct result of human activity?

Do you believe this carbon has an impact on climate?

Do you believe elevated temperatures worldwide is bad for the biosphere, causes species extinction, habitat destruction, etc.?

Do you believe that's bad?

The temperature increase can happen during the night. Increased CO2 might benefit plant life making the planet greener.

Is it too late? It probably is.

Nth order effects will have the most impact. Methane leaking from Siberian ice is equivalent to 125 years of 2019 CO2 emissions. When that happens it’s over.

Species extinction and habitat destruction are currently driven by industrial and agricultural expansion and pollution.

We talk about oil spills or methane leaks but the agricultural waste flowing down the Mississippi destroys more life than oil spills every year.

We had cold spell in central europe for couple of weeks (not sure about the rest of the northern hemisphere), that could explain the extra snow. Now we're back at +-normal temperatures for this time of the year. All of which tells very little about arctic ice - in fact despite this cold spell water is warmer than usual. Not good

Reply on news.ycombinator.com