Saturday, December 12, 2009

Keeping Global Temperature Rise Below 1.5°C Is Almost Impossible

When it comes to global warming there is little that the countries of the world seem to agree upon except perhaps that the rise in global temperature should be kept below 2°C (3.6°F). But now even that point of consensus has been shattered by a proposal at the climate meeting in Copenhagen by small island nations and poor African countries that the rise in temperature should be kept below 1.5°C. But according to climate science is that even possible? In a report from the BBC, the head of climate science at the UK’s Met Office, Vicky Pope, says "There's no way you'd get a 50% chance of avoiding 1.5°C…If you reduced everything to zero immediately you'd still get about 1.3°C because of the greenhouse gases already in the atmosphere." She noted that policies to ensure a reasonable chance of remaining under 1.5°C would involve "negative emissions" - sucking CO2 out of the air. So why are so many countries and climate activists embracing what seems to be virtually an impossible goal? Perhaps it is a symbolic way at making a statement that the richer countries are not doing enough. Or perhaps it is an act of desperation since anything approaching a rise in temperature of 2°C would probably lead to a sea level rise that would obliterate many of the small island countries and cause climate change in Africa that would be devastating.

What should the goal be? The 2°C target would expose us to a high risk of catastrophic climate change but while extremely difficult to meet according to the experts it remains realistically possible whereas the 1.5°C target would reduce the risks of catastrophic climate change but is apparently an unrealistic goal. Having postponed real action on this issue for two decades the world is left with no good choices.

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