PWC talks of carbon debt

PriceWaterhouseCoopers LLP (PWC), recently released a study suggesting that “we have been eating into the finite carbon emissions budget more quickly than we should, leaving us with a carbon debt.”

The study goes on to note that according to its calculations and modeling, the world has been reducing its “carbon intensity,” the carbon emitted per unit of GDP, at just 0.8 percent per year between 2000 and 2008.

The study suggests that we need to change course, sharply: to a 3.5 percent annualized reduction in carbon intensity between 2008 and 2020, merely to get back on a safe path, and so that we can stabilize global CO2 parts-per-million at around 450, which the study claims is the minimum needed in order to “stand a fair chance” of limiting average global changes in temperature to 2 degrees Celsius. If the world is not on course by 2020, there will be real problems. If stasis continues, it “could require rates of decarbonization over the longer term that are incompatible with growth, and put the 450 ppm goal out of reach.”

The world GDP was generally growing through those years, so that even though carbon emitted per unit of GDP went down slightly, total carbon emissions rose, year-on-year, on the whole. In order to reach the goals the PWC study stipulates, the world would have needed to “decarbonize” at the rate of two percent per annum throughout the 2000-2008 period. We’re already seriously off-target.

In order to move forward, the world must, first, budget carbon allocations. First, that involves a roof on total gigatons of CO2: 1,300. Next, distribute that CO2 budget among various countries or groups of countries. The study suggests that China should get to emit 28 percent of that CO2, the United States 16 percent, India 9 percent, the EU 10 percent, with the rest divided up among the rest of the countries of the world.

The PWC models are predicated on a 450 ppm standard when the IPCC has warned that 450 ppm isn’t enough and will bring disaster to places like Maldives and Bangladesh.
Also, the PWC study deals with carbon intensity rather than carbon output, trying to carve out a path in which GDP growth can continue, essentially unabated, so long as the amount of CO2 dumped into the atmosphere per unit of GDP goes down.

This would have been fine so long as growth yields if atmospheric CO2 concentrations are on an unacceptable trajectory, rather than the limits for CO2 emissions. But the study notes how the opposite is happening. And that the key nations aren’t meeting obligations!

Is carbon intensity yet another way of not accepting the reality of climate change and continuing with emissions? What do you say?

Does a carbon budget make sense?