By Colby Cosh - Wednesday, December 12, 2012 - 0 Comments
The CBC provided us with an interesting case study in science reporting on Monday as its “community team” blog trumpeted “UN climate change projections made in 1990 ‘coming true.’”
Climate change projections made over two decades ago have stood the test of time, according to a new report published Monday in the journal Nature.
The world is warming at a rate that is consistent with forecasts made by the UN’s Intergovernmental Panel on Climate Change 22 years ago.
Climate scientists from around the world forecasted the global mean temperature trend for a 40-year period, from 1990 to 2030—and at this halfway point the report authors have found the projections “seem accurate” after accounting for natural fluctuations.
These are absolutely all the numbers you are going to get out of this news item. And if you peruse the new assessment of the 1990 IPCC predictions, which was actually published on the Nature Climate Change website, what you find is a more nuanced picture than the CBC’s “They nailed it, no worries” interpretation implies.
David Frame and Dáithí Stone write that the 1990 IPCC report predicted a rise in global mean temperatures of between 0.7 degrees C and 1.5 degrees C by the year 2030; on a linear interpolation, we might have expected half the increase to have occurred by now. The actual observed warming during the past 20 years (almost all of it taking place in the first ten) has been in the vicinity of 0.35 degrees C to 0.39 degrees C, “on the borderline” of the range given in 1990. In other words, the IPCC’s point estimate was high, and the overall warming has been consistent with the outer confidence bounds of their stated prediction, but barely.
Frame and Stone think, with some justification, that this is a pretty good performance given the simplicity of the climate models available at the time. It’s especially good, they think, because the models could not predict what would happen in the economy, or below the planet’s crust. Their story is that the Earth caught a series of lucky breaks despite the substantive failure of greenhouse gas reduction efforts.
The highlighted [IPCC] prediction assumed a business-as-usual scenario of GHG emissions; three other scenarios were considered and in fact Scenario B (which assumed a shift to natural gas, a decrease in the deforestation rate, and implementation of the Montreal Protocol, all independent of global climate negotiations) was closer to the mark as of 2010, especially with respect to methane emissions… Of course, [even these Scenario B] predictions were based on idealized future scenarios that did not foresee the eruption of Mount Pinatubo, the collapse of the Soviet Bloc industry, or the growth of some Asian economies, so one could argue that the prediction is right for the wrong reasons.
The authors conclude by noting that predicting the future is a lot harder than predicting the past—and, unfortunately, the resolving power of crystal balls has not improved much since 1990.
…the 1990 prediction following [the IPCC's] business-as-usual scenario covered a full 0.4ºC range due solely to uncertainty in the climate sensitivity that has not narrowed substantially so far, whereas a larger range was implied by the examination of further scenarios of emissions and a larger range still should have been considered owing to uncertainty in the evolution of natural forcings and internally generated variability.
Believers in and skeptics of the threat from anthropogenic climate change will both find promising fodder in this paper for conversion into mountains of delicious hay. (Mind the carbon emissions, though.) I’ll resist the temptation to join in that exercise, but it is very clear that the authors’ “Well done” message to the IPCC carries a sizable asterisk. If the CBC is going to report on a scientific paper, why not show some indication somebody has read it?
By Alex Shimo - Friday, December 19, 2008 at 3:44 PM - 57 Comments
Perhaps this is a thought that dare not speak its name, yet it has…
Perhaps this is a thought that dare not speak its name, yet it has haunted me ever since Canada came under such strong criticism at the UN climate talks in Poznan talks. Could Canada gain geopolitically from climate change, and if so, was that the reason why we were doing so little about it? This is a cold, callous idea, and one that would horrify most Canadians. Yet it is the viewpoint of Atlantic Monthly columnist Gregg Easterbrook, who wrote:
“In recent years, Canada has increased its greenhouse-gas output more rapidly than most other rich countries. Maybe this is a result of prosperity and oil-field development – or maybe those wily Canadians have a master plan for their huge expanse of currently inhabitable land.”
In this article, Easterbrook, author of the Progress Paradox, examines which countries stand to gain and which countries will lose from climate change. Shanghai, Hong Kong, the Netherlands, Bangladesh and Venice will obviously will be in big trouble with the sea level rises expected by 2100. But a few countries – like Sweden, Greenland and Denmark, stand to gain greatly. And Canada, as a a cold, rich, sparely populated country, he writes, will likely make a killing.
Machiavellian, isn’t it?
By Alex Shimo - Wednesday, December 10, 2008 at 3:33 PM - 5 Comments
Canadians are doing moderately well at going green according to a new study by…
Canadians are doing moderately well at going green according to a new study by Statcan.
About 45% of Canadian households had made a real switch, according to the study, doing things like composting, switching to low flow toilets, and changing to low flow shower heads.
Another 45% of Canadian households had made some changes, but there were a number of switches they could still make.
About 97 per cent of Canadians with access to recycling programs take advantage of them, but only 30 per cent compost.
Interestingly, whether or not Canadians are taking action is related to how much they earn. About 60 per cent of households with incomes of more than $100,000 were very environmentally active, but only 35 per cent of households with incomes of $28,000 or less, according to the study.
Homeowners were also more likely to be very environmentally active than renters. About 54% of homeowners were “very active” compared with 22% of renters. Continue…