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Antarctica Is Melting Three Times As Fast As a Decade Ago (nytimes.com)
An anonymous reader writes: Between 60 and 90 percent of the world's fresh water is frozen in the ice sheets of Antarctica, a continent roughly the size of the United States and Mexico combined. If all that ice melted, it would be enough to raise the world's sea levels by roughly 200 feet. While that won't happen overnight, Antarctica is indeed melting, and a study published Wednesday in the journal Nature shows that the melting is speeding up. The rate at which Antarctica is losing ice has tripled since 2007, according to the latest available data. The continent is now melting so fast, scientists say, that it will contribute six inches (15 centimeters) to sea-level rise by 2100. That is at the upper end of what the Intergovernmental Panel on Climate Change has estimated Antarctica alone could contribute to sea level rise this century.
"Around Brooklyn you get flooding once a year or so, but if you raise sea level by 15 centimeters then that's going to happen 20 times a year," said Andrew Shepherd, a professor of earth observation at the University of Leeds and the lead author of the study. Even under ordinary conditions, Antarctica's landscape is perpetually changing as icebergs calve, snow falls and ice melts on the surface, forming glacial sinkholes known as moulins. But what concerns scientists is the balance of how much snow and ice accumulates in a given year versus the amount that is lost.
"Around Brooklyn you get flooding once a year or so, but if you raise sea level by 15 centimeters then that's going to happen 20 times a year," said Andrew Shepherd, a professor of earth observation at the University of Leeds and the lead author of the study. Even under ordinary conditions, Antarctica's landscape is perpetually changing as icebergs calve, snow falls and ice melts on the surface, forming glacial sinkholes known as moulins. But what concerns scientists is the balance of how much snow and ice accumulates in a given year versus the amount that is lost.
I hate how many otherwise intelligent people completely misunderstand global warming. Although people are contributing a fair amount to the rate at which we are warming up, this planets default temperature is much MUCH higher than what our species is comfortable with. Guess what? If you are reading this, you were born during an ice age: https://en.wikipedia.org/wiki/...
So what? From a human perspective (arguably the thing that matters most to you and me), normal is what we have now, and any deviations from that are going to cause us pain and suffering. It might be inevitable, but it's absolutely in our best interest to have it happen as slowly as possible. Cities, industries, and crops are where they are; moving them or hardening them is gonna be hella expensive and would be better done over long periods of time. Not to mention that really fast rates of change could destabilize the very fabric of our societies. That's nice that we're in an "ice age", but it means diddly squat to whether or not we should be trying to reduce our contribution to climate change.
The Rate of global warming is the biggest issue. Just like falling it is your rate of speed that you hit the ground is what will kill you.
The world isn't ever "Normal" it is always in flux, but if we change it too much a lot of things can die.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
So which is it?
The NASA article is dated Oct 2015, and it claims that the gains in West Antarctica outweigh the losses in East Antarctica. The Nature article is dated 2018, it specifically addresses the NASA data, and claims that they have even better analysis of the satellite information. This is what peer review is for. Hopefully NASA was consulted in this paper.
Okay, I'll bite.
The two studies do indeed contradict each other. They use different methodologies. The Journal of Glaciology "Antarctica has been gaining mass" presser linked there (here's the paper, I believe) appears to use altimeter measurements alone, while the Nature paper uses a combination of altimeter data, gravimetry, and the "input-output" method which appears to estimate glacier melt and snow accumulation more directly. (You may have paywalls, I'm at a university.) Which paper to trust? I'm not a glaciologist, I can't answer that.
And yeah, the confidence intervals in the Nature paper are kind of wide. Measuring the mass of ice on a sparsely-populated continent is actually pretty hard, I suspect. But an estimate at either end of the CI still means you're losing a bunch of ice. With your engineer... I'd hope your response would depend on what question you were asking. Are 0 and 100 both numbers you can deal with? Is your acceptable range 40 – 60, or -1000 – 1000? Raw numbers are meaningless without context.
The main takeaway from the two papers are kind of similar, though. There's a LOT of ice in Antarctica. Sea levels are, right now, measurably rising — I mean, "FLOODING" is happening in coastal communities now. Dealing with it is really expensive. If Antarctica's ice melts faster, we'll see more flooding, sooner. If your argument is "increased global temperatures will increase Antarctic snowfall enough to more than offset faster melting," sure, make that argument, but the scientist in the NASA press release you linked to says the exact opposite:
If you are reading this, you were born during an ice age
Come on, not everybody here is my age.