Hey John - how do you think we could cool the arctic?
Elizabeth Cary
Cambridge
On Nov 19 2013, John Nissen wrote:
>Hi Kevin,
>
>Thank you for this article which shows that the Arctic is now warming 8
>times faster than the rest of the planet. The commonly held view is
>that the Arctic is warming just twice as fast as global warming - the
>global average. This is called "Arctic amplification", as if there were
>some mechanism that takes the global warming (or the driver of global
>warming) and amplifies it in the Arctic by a fixed factor. I think this
>is a misconception. What has happened is that warming in the Northern
>Hemisphere has heated the currents flowing into the Arctic, which
>started a retreat of sea ice in the 80s. This retreat led to albedo
>loss, heating of the Arctic Ocean, and further retreat of sea ice, in a
>vicious cycle of positive feedback. Because it was a feedback, it had
>non-linear effects. The sea ice extent has shown a non-linear retreat
>by its variation from the IPCC sea ice models in the AR4 report of April
>2007. The variation started appearing in the 80s, and was marked from
>90s onwards. Along with this non-linearity of retreat there was also a
>non-linear warming of the Arctic. This has built up so that now the
>Arctic is warming about 8 times faster than the rest of the planet.
>
>The Arctic temperature is now several degrees higher than it was thirty
>years ago, and the largest rise has been in the last decade. This has
>reduced the temperature gradient between tropics and pole, making the
>jet stream meander and get stuck, leading in turn to climate extremes,
>crop failures and an increase in the underlying price of food to above
>the crisis level in many countries - a level at which people rebel
>against government because they haven't got enough food.
>
>The annual albedo loss gives a heat input to the Arctic which
>accumulates each year. Assuming albedo loss is now the main driver of
>Arctic warming, we can expect the warming rate to double by the time we
>have five or six months of the year with the ocean virtually free of ice
>(less than 1 million km2).. The non-linear trend lines for various
>months indicate that this date is around 2020.
>
>To allow the Arctic to continue warming and sea ice to melt away would
>be catastrophic for several reasons. Not only would the food crisis
>deepen, leading to widespread conflict and starvation, but the
>escalation of Greenland Ice Sheet melt, permafrost thaw and Arctic
>methane emissions would be unstoppable, leading to many metres of sea
>level rise and many degrees of global warming, methane being a potent
>greenhouse gas. This is why it is essential to cool the Arctic as soon
>and as quickly as possible. We are rapidly approaching the point of no
>return.
>
>Cheers,
>
>John
>
>--
>
>On 18/11/2013 20:33, KEVIN COLEMAN wrote:
>> Now we know where it is and it disproves the theory that global
>> warming had stalled.
>>
>> http://phys.org/news/2013-11-discovery-prompts-global.html#nwlt
>
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