Published on July 14th, 2011 | by Joshua S Hill
Worst Case Scenarios Not Worst Case Enough
A new study has found that the worst case scenarios calculated by the Intergovernmental Panel on Climate Change which were released in 2007 may not realistically calculate the actual worst case scenarios facing planet Earth and her inhabitants.
The study was conducted by climate researchers in the US and Switzerland and provided worst case scenarios which were even more drastic than those released in the 2007 IPCC Report.
Their scenarios were not derived from the unrealistic, but were simply pessimistic. Calculations were based on pessimistic population growth and energy usage.
The researchers assumed that per capita energy consumption will grow at a constant rate and that by 2100 the total consumption levels will be four times what they are today. The population growth scenarios also predict that Earth’s human population could grow to 15 billion people by the same time.
In one scenario that the researchers generated, they also supposed that coal would become the dominant source of energy production, accounting for more than 90% of all primary at the end of the century. Given the abundance of coal and current political leanings, this is not such an unrealistic concept to come to grips with.
In another scenario, the researchers calculated the total percentages of energy sources today and rolled them forward through the remaining years of this century without any changes: they also assumed a total lack of change in the atmospheric carbon dioxide levels.
In the first scenario, temperatures were found to increase by up to 5.1 degrees on the 1990 levels, and that temperatures around the North Pole would increase by 11 to 12 degrees.
In the second scenario, global temperatures still increased by 3.7 degrees, reminding us just why we need to reduce our carbon dioxide emissions and not just halt them where they are.
The new scenarios also pointed to climatic shifts in other regions of the planet if things continue apace. Annual precipitation in Europe could fall by anywhere between 20 and 60 percent, while at the same time rainfall could increase over the Sahara Desert.
Unsurprisingly, Arctic sea ice is expected to be entirely gone by 2070 under these scenarios.
Professor at ETH Zurich, Reto Knutti, an author of the report which was published in the journal Environmental Research Letters, warned that there is still no need to jump to conclusions, and that their results did not constitute predictions, nor did they provide any probabilities as to the likelihood with which their predicted futures may come to pass.
“These scenarios show very pessimistic extreme cases, and there is no proof that these will eventuate,” said Knutti. He also explained, however, that it is important to explore all possibilities. “It would be a mistake to look at a range that is too restricted”.
Source: ETH Zurich