Normally the summer season for Arctic sea ice finishes mid-September. By this point, the ice has melted to its minimum extent - historically about half that of the winter freeze - and starts to freeze over again.
This year, by mid-September, the sea ice shrank to under 3.75 million sq km, about a quarter of its winter size, representing the second lowest size on record (the lowest being in 2012 where a freak cyclonic storm broke up the ice shelf).
And it hasn’t yet started re-freezing five weeks into the winter season. The edge of the ice north of Scandinavia and European Russia has stayed where it was, and the ice north of central Siberia has actually retreated further.
The ice will start refreezing soon, but the size of the melt and, particularly, the delay in the refreeze have already set alarm bells ringing in the scientific community. Why?
Firstly, because it only takes one year in which the Arctic sea ice fails to freeze to see the end of it for good.
The ice shelf is composed of multiple layers: fresh ice on the surface, which is (until now) recreated every year, and below this and closer to the pole, layers and layers of ice which have existed or been created since the last ice age. These deeper layers are shrinking each year, and once they’re gone, even if a winter freeze sees some surface ice created, they won’t be able to regenerate.
And secondly, scientists are still divided as to whether the loss of the Arctic sea ice might represent a ‘tipping point’ event significant enough to tip the world’s climate into much faster and irreversible warming.
The Arctic sea ice, in winter one-and-a-half times the size of the United States, functions as a giant mirror, reflecting the sun’s energy back into space. Every year it shrinks smaller it becomes less effective. Worse, the surface area it was covering is replaced with open water which absorbs the sun’s energy, rather than reflecting it. Beyond a certain point, this positive feedback loop becomes unassailable and there’s no way to prevent the loss of the ice for good, and the creation of what is effectively a new global warming machine.
As we all (hopefully) now know, the warming causing the melting of the ice in the first place is being driven primarily by man-made greenhouse gas emissions. And here’s the real stinker: there’s already enough CO2 in the atmosphere - before next year’s emissions, and 2022s, and 2023s... to melt all of the Arctic sea ice, and for good. Without net negative carbon capture or some form of (as yet understood, designed and engineered) geoengineering, the Arctic ice is gone. Could be in the next five years, could be 20 years away; it’s just a matter of time.
https://earthsky.org/earth/arctic-sea-ice-2020-minimum-2nd-lowest-on-record
Off topic: Arctic beyond the tipping point
posted on 15/11/20
comment by Winston (U16525)
posted 16 minutes ago
Rosso, hasn't the number of people living in extreme poverty fallen consistently?
I'm not trying to dismiss your concerns but just keen to understand why these things come up for discussion as if we're heading for certain catastrophy, given things are improving in many areas?
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That’s not really relevant to the discussion beyond the fact that surely we want to work as hard to protect those gains as we did to achieve them.
Climate change is going to impact the health, wealth and wellbeings of all of us to an extent, and billions of people very severely indeed.
It is, in fact, already doing so to farmers, to give the most obvious example, in many parts of the world. Water shortages are already helping precipitate conflict in the Middle East and Africa.
And again, we haven’t seen the real impacts yet. Those come down the line as the global temperature continues to creep up.
We are yet to see the ecological, geological or human impacts of the greenhouse gas emissions of even the 1990s and 2000s play out, because although those effects are already baked in, and we are going to have to deal with them down the line, they haven’t translated yet.
posted on 15/11/20
rosso - it’s not good enough to be right; you have to be effective (U17054)
Of course it's relevant.
Climate change has been happening for quite a while now (!) yet many of the key indicators that we would both reference when we talk about this subject are improving.
How can we talk about a crisis, with poverty coming down and lives improving?
I'm not saying this means it's all fine.
I'm saying this demonstrates that we need a little more context to this discussion instead of hyperbole and scaremongering.
posted on 15/11/20
Re. climate change and its effects acting as ‘threat multipliers’ to human conflict, here is a quick introduction that discusses the Syrian Civil War:
https://www.scientificamerican.com/article/climate-change-hastened-the-syrian-war/
How much of a role the droughts in Syria worked to further quell civil unrest and also whether the droughts might have or were as likely to have occurred without the impact of MMCC are still subject to academic debate.
But at the very least, as a thought experiment if nothing else at all, the case study should serve as a warning.
posted on 15/11/20
comment by Winston (U16525)
posted 5 minutes ago
rosso - it’s not good enough to be right; you have to be effective (U17054)
Of course it's relevant.
Climate change has been happening for quite a while now (!) yet many of the key indicators that we would both reference when we talk about this subject are improving.
How can we talk about a crisis, with poverty coming down and lives improving?
I'm not saying this means it's all fine.
I'm saying this demonstrates that we need a little more context to this discussion instead of hyperbole and scaremongering.
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We’ve seen a two degree increase in the last 150 years. And the effects of that increase, the bulk of which has happened in the last 50 years, haven’t been fully delivered yet.
At current emissions rates, we’re predicted to see a further three to five degree increase in the next 80 years. We haven’t really seen much yet versus that which is to come.
Every year, however, we are seeing more. If we were to reconvene here in ten years time, my prediction would be that we’d be having a very different discussion about the matter, because I think people’s perspectives are going to change a lot in the next decade as we start to see more of the human impact.
RR made a good point earlier about the rhetorical use of language, and the best modes of delivery to use to try to persuade people that they have to start making changes in their day to day behaviour and lifestyles.
I agree with you that what might even just be considered inflammatory scaremongering, even if it is scientifically supported, might be counterproductive, and that is something that policymakers and campaigners alike should be thinking about carefully.
posted on 15/11/20
Winston, I apologise if I offended you. And I apologise if I haven't been clear enough - I tried to be clear about my view of things but perhaps I indeed relied too much on 'scientific consensus' as shorthand.
I'll be more specific. As I think I've already mentioned, I am going by the IPCC headline stance, which is backed by overwhelming scientific consensus and most of the world's governments. For instance, a 1.5°C average rise is projected to put 20-30% of species at risk of extinction, while if the planet warms by more than 2°C, most ecosystems are expected to struggle. I could list more of those headlines but I think it makes more sense to share a link to a good example of what I understand to be the core of how science understands the picture right now:
https://www.ipcc.ch/sr15/
In my understanding, this represents the overwhelming mainstream of current science in terms of the central objectives of averting climate crisis and consequences of failure and - while acknowledging the uncertainties around the margins of present understanding - I think it's pretty compelling.
That's my understanding of the facts. Beyond the facts we can exercise our judgement as to how seriously we perceive the implications. That's a question not of objective reality, but of our individual values, priorities, etc. For me, the projected consequences of a failure to limit to 1.5°C rise are catastrophic, let alone those of 2°C+.
Let's see if you dispute the factual basis of the report, and/or how you view the gravity of the scenarios projected. Do you doubt the negative impacts, and if so, are you confident enough that you don't think we need to deploy the precautionary principle? Do you view those negative impacts as worth mobilising unprecedented forces to adapt our economic behaviour to avert? Do you endorse the goal of limiting global temperature rise to 1.5°C?
posted on 15/11/20
As Rosso has said, the most drastic effects of temperature rises aren't scientifically projected to impact on natural habitats yet. But we are currently going through a period of mass extinction already. We're seeing ever more regular droughts and extreme heat waves in southern Europe, parts of which are likely to be effectively become an extension of the Sahara as these trends persevere.
People have been lifted out of poverty above all thanks to technology raising productivity. That's a great achievement of humanity, but it's despite the depletion of natural resources and the insidious impacts of climate change. Just because the effects of economic growth have been more visible than the impacts of environmental degradation over the last few decades doesn't mean that technology + capitalism are mightier per se than the limitations of the natural environment to support life.
posted on 15/11/20
rosso - it’s not good enough to be right; you have to be effective (U17054)
Two issues there.
Firstly, the predictions regarding increases in temperature have been wrong in the past, so we cannot just assume they are correct and base all our plans on that.
Secondly, whilst the full effects may not have been felt yet, surely if we were heading for catastrophe then things like poverty and extreme weather would be clearly heading in the wrong direction?
posted on 15/11/20
Red Russian (U4715)
No worries and thanks.
I will take a read of the link you shared.
Let's remember though, there are several issues at play here and one of the key issues I have been referring to is that of human existence.
This was the particular point I picked up on:
"devastating consequences for human life"
And the part that I'm struggling to see justification for.
That doesn't mean I'm disregarding all other issues on this subject and all other forms of life, but this is certainly where my main complaint with the reporting of this subject comes from.
You say:
"but it's despite the depletion of natural resources and the insidious impacts of climate change."
That's absolutely correct.
It tells us that currently, humans are able to manage the effects of change and continue to improve standards of living.
So how can that be the case, yet we're facing such obvious impending doom?
posted on 15/11/20
Winston, maybe it's helpful to clarify what we mean by 'doom' or 'catastrophe'. I wonder if what you are thinking of is something close to human extinction. If so, I think you'd be right to suggest being cautious about such predictions. For me, the nightmare scenario is substantial areas of the inhabited planet no longer being able to support human population at current levels, together with an increasing vulnerability to droughts, crop failures and extreme weather in other regions of the world, and depletion of the natural environment on earth and in the oceans, in turn creating conditions for conflict and political instability. I have little doubt that we as a species will adapt and survive, but that in itself for me is not a comforting proposition to settle for against a backdrop of human misery and the prospect of our descendents living in a more dangerous world than ours.
posted on 15/11/20
RR, I wouldn’t go that far.
For me, devastation is linked to quality of life, globally, which links into things like poverty, death and extreme weather events.