11 September 2007

Arctic meltdown

The news from the Arctic just keeps getting worse. The events currently unfolding in these regions are the clearest indication that something is amiss with the climate system.

The most obvious effect is the vast reduction in the areal coverage of Arctic sea ice. As of 4 September, the previously observed record low has declined still further, to 4.42 million km^2. A new update should be available in the next few days.

One result of the melting ice is that the long sought after Northwest Passage also opened to non-icebreaker ships for the first time since observations began in the 1970s. The image below, from the NASA Earth Observatory website, shows the unprecedented event from a satellite perspective.

The permafrost is also melting in many areas of the Arctic. According to the article, the feedback effects that this is likely to have are uncertain. From the article:

Permafrost collapse in peatlands tends to result in the slumping of the soil surface and flooding, followed by a complete change in vegetation, soil structure, and many other important aspects of these ecosystems...vegetation responds to the flooding with a boost in productivity. More vegetation sequesters more carbon away from the atmosphere in plant biomass.

It's not all good news, though...

...[T]he report also cautions that this flooding associated with collapsing permafrost also increases methane emissions. Methane is an important greenhouse gas, which is more powerful than carbon dioxide in its ability to trap heat in the earth’s atmosphere.

Unfortunately, the methane release will likely eventually balance or outweigh whatever the sequestration effect is observed.

There are also ominous signs that the melting of the Greenland ice sheet is accelerating (from The Independent)...

High up inside the Arctic circle the melting of Greenland's ice sheet has accelerated so dramatically that it is triggering earthquakes for the first time.

Scientists monitoring the glaciers have revealed that movements of gigantic pieces of ice are creating shockwaves that register up to three on the Richter scale.

The speed of the arctic ice melt has accelerated to such an extent that a UN report issued earlier this year is now thought to be out of date by its own authors.

The effect on ecosystems of the North is severe. Spring is now arriving about a fortnight earlier, with consequences for the biomes of the region.

A study of a range of animals and plants living in the high Arctic has revealed that many of them are responding to the earlier spring by flowering or laying their eggs significantly ahead of their normal times of the year.

On average, the breeding and flowering seasons in the Arctic have shifted by 14.5 days but some species of mosquitoes have begun laying their eggs 30 days earlier than in the mid 1990s...

...[T]he change in timing of emergence, egg-laying and flowering could disturb local food
webs with some animals appearing ahead or behind of others on which they rely for food.

The changes in the Arctic are also affecting polar bears, which are now expected to be functionally extinct in some regions as soon as 2030. Read the excellent posts on this over at Climate Progress and at The Island of Doubt.

That these changes are related to global warming seems obvious. The claims of the Deniers and doubters are disappearing faster than the Arctic ice. The time for action is now. Half-hearted, insincere measures like the recent APEC agreement won't do the job that needs to be done. The UN says that 2/3 of the emissions cuts for the future need to come from developing countries. That may be, but the developed world democracies must also play a major role -- in political and scientific leadership, in developing and implementing the appropriate policies and in financial and technical support for making the necessary adjustments. Citizens of these democracies must bring the issue of climate change to the forefront in upcoming elections and choose leaders who will lead, rather than those who deny, obfuscate and try to sustain the unsustainable status quo. It is the only way forward.

1 comment:

George said...

Thanks for your article. Unfortunately, we are past the point of no return. Even if China wakes up when Shanghai is underwater, it is too late to reverse the depredation our species has caused. Can we slow it down? Perhaps, but hardly realistic. As the permafrost melts and releases methadone and CO2 into the atmosphere, oil companies welcome the defrost and they will drill and guzzle.