Climate change is ahead of schedule, but not yet beyond the ‘point of no return', according to the Climate Safety report, out last week. The IPCC's assessment of global climate change does not factor in recent research on feedback mechanisms, says the Public Interest Research Centre report. More up-to-date research shows that climate change is happening faster than previously believed. For example, Arctic experts predict a complete melting of summer ice by as early as 2011-2015, a full 80 years earlier than the IPCC concluded.
So what did the IPCC leave out? And how does the newer research change global targets?
Anyone who has been watching the environmental headlines this year will know that Arctic sea ice retreated further than ever before in 2008. While the media described this as a tragedy for the polar bear, the consequences of Arctic ice loss are considerably broader. As Richard Spinrad of the National Oceanic and Atmospheric Association says, "what happens in the Arctic does not stay in the Arctic."
The most serious problem is the negative feedback from lost reflectivity that would be a result of less ice. Currently the vast expanses of white ice at the poles reflect back a significant amount of sun
light. Any loss in the reflectivity, or albedo, of the earth as a whole will have an accelerating effect on climate change. White ice has a high albedo, reflecting 80-90% of the sunlight that reaches it back into the atmosphere. The ocean on the other hand, being dark, absorbs 90% of the sunlight. As the ice melts, the highly reflective surface is replaced by the heat aborbing water, and that warmer water then melts the ice faster. This ‘albedo flip', from reflective to absorbing, was not included in any detail in the IPCC climate modelling.
Permafrost is defined as an area of ground that remains frozen even in summer, and large expanses of North America, Russia, and Northern Europe qualify. The frozen soil is often carbon-rich. In fact, there is more CO2 bound up in the permafrost of Siberia alone than there is currently in the earth's atmosphere.
As the Arctic warms, the permafrost will thaw, releasing carbon into the atmosphere. With an estimated 1672 billion tonnes of CO2 locked away in frozen earth, the 8 billion tonnes a year that we release through burning fossil fuels suddenly looks insignificant. Permafrost could be a major factor in the speed and severity of climate change, but according to Oliver Frauenfeld of the National Snow and Ice Date Centre, "permafrost is not incorporated at all in any global climate models right now".
The two factors above bring us to the Greenland ice sheet, the glacier that lies across much of the country and contains 6% of the earth's fresh water. Melting sea ice does not cause sea levels to rise, as no water is displaced. The Greenland ice sheet is land ice, and if it were to melt entirely it would be the equivalent of pouring 2.9 million cubic kilometres of extra water into the ocean. That would cause sea levels to rise - by an impressive 7 metres.
It has been estimated that it would take 1,000 years for the ice sheet to disappear, but more recent measurements show that the edges of the ice are retreating 10 times faster than was previously thought. 2007 saw the most serious summertime ice melt in Greenland on record.
In conclusion, say the Climate Safety authors, "the observed impacts of climate change have raced ahead of the predictions made in the IPCC's 2007 report, even in the short time since it was published." Because of the complexity of climate modelling, it takes years to include new data sets into the equation. It is unlikely that new research can be factored in soon enough to deliver targets that are still achievable. Instead, we need to assume a worst case scenario. The authors point out that nobody plans for a ‘medium-sized terrorist threat' - "this is not how we as a society tend to deal with risk... we should therefore be asking why we as a society are preparing for ‘medium sized climate change."
The good news is that we haven't passed a point of no return. It is not too late to implement a range of measures, including ‘easy-win' solutions that will help CO2 emissions to peak early. These early wins are efficiency measures such as insulation or smart metering. Medium term measures include investing in public transport and cutting domestic flights, and reducing the speed limit to save emissions from cars. While this is underway, longer term projects can begin, such as protecting or re-foresting carbon sinks wherever possible, switching energy plans to renewables, and investing in research and development into promising new technologies.
The climate debate seems to take a new turn every week. The Climate Safety report is a useful summary of many of those recent turns, and includes many practical policy suggestions that I haven't been able to include here. I would recommend downloading it (pdf) and exploring it further.
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