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Cutting greenhouse gas emissions is urgent says new Arctic report

  • 06 May 2011, 11:00
  • Verity

A major report evaluating the latest Arctic science has been released this week, and the results are unambiguous: the Arctic is changing at an unprecedented rate, it's down to climate change, and greater urgency is needed in tackling the problem.

The report was compiled by scientists from the Arctic Monitoring and Assessment Programme (AMAP) - an organisation of leading Arctic experts set up by the Arctic rim countries - and released to over 400 scientists at a conference in Copenhagen.

 

The report found that Arctic ice and snow cover has declined, and seasonal sea ice does not last for as long as it once did. Permafrost (persistent frozen ground) is no longer so extensive. Glaciers and ice sheets have been melting far faster this decade than they did in the previous twenty years.

This is all down to the substantial warming that the Arctic has experienced. The Arctic has warmed at around twice the average global rate since 1980. And this warming has been found to be directly attributable to human activities.

Scientists are now seriously concerned about the state of the Arctic, especially since the recent sea-ice loss has been faster than projections by the models used in the IPCC AR4 report (published in 2007).

Recent research has uncovered snow and sea ice feedbacks (natural processes that either exacerbate or reduce warming). For example, the loss of summer sea ice allows the ocean to absorb extra heat in summer, which is then released in the autumn, further warming the lower atmosphere.

Of the newly identified feedbacks, eight are positive, and will further increase warming, while only one is negative, reducing warming.

According to the report, Arctic ice loss has led to the flow of huge amounts of freshwater into the ocean, causing nearly half of the global sea level rise between 2003 and 2008. And with temperature rise of between 3 and 5 ˚C predicted by the end of the century (even under low greenhouse gas emission scenarios), the contribution of melting ice to sea level rise is set to increase. The latest research suggests that global sea levels could rise between 0.9 and 1.6 metres by the end of the century - the headline conclusion picked up in much of the media coverage.

It's not only sea levels that are being affected by the Arctic getting warmer. The loss of permafrost allows thawing organic matter to decay and break down, releasing extra carbon dioxide into the atmosphere. Continued warming could also lead to the melting of gas hydrates (solid methane deposits) trapped in the permafrost and seabed. Methane is a highly effective greenhouse gas, and its release into the atmosphere could cause additional warming.

The impacts of the Arctic ice loss are likely to be mixed for the Arctic locals - although their infrastructure and way of life are at risk, the melting ice could allow easier access to natural resource deposits and open new sea routes.

However, the impact of Arctic warming on global sea level is likely to adversely impact the rest of the world - Andrew Steer, the World Bank's special envoy for climate change, suggests that poorer communities are likely to be particularly affected since "they tend to live in the lowest lying land and have the fewest resources to adapt."

One of the main conclusions of the report is that "cutting greenhouse gas emissions globally is urgent" - and it seems that getting this particular message across has been a key concern.

During the AMAP conference in Copenhagen this week James White of the University of Colorado at Boulder highlighted just how important it is for scientists to use simple language and focus on the big picture when talking about climate change with a wider audience.

He said that those hostile to mitigating the use of fossil fuels "sow the seeds of doubt that give the people the impression that ... unless every single one of us lines up behind an idea, that decisions can't be taken."

 

 

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