I want to highlight a few points from the IPCC’s Mitigation Report (PDF).
First, even the most stringent global greenhouse gas targets can be met at a cost of a mere 0.1% of GDP per year!
While the report is not explicit about when action should be taken, it does say that:
In order to stabilize the concentration of GHGs in the atmosphere, emissions would need to peak and decline thereafter. The lower the stabilization level, the more quickly this peak and decline would need to occur.
The Center for American Progress and I have encouraged stabilizing atmospheric CO2 concentration at 450 ppm and/or a temperature rise of 2 degrees Celsius over the pre-industrial era. That said, according to one of the report’s charts (see page 22), reductions aimed to cut emissions 85% by 2050 must be initiated before 2015.
And maybe sooner. According to the IPCC:
Decision-making about the appropriate level of global mitigation over time involves an iterative risk management process that includes mitigation and adaptation, taking into account actual and avoided climate change damages, co-benefits, sustainability, equity, and attitudes to risk. … if the damage cost curve increases steeply, or contains non-linearities (e.g. vulnerability thresholds or even small probabilities of catastrophic events), earlier and more stringent mitigation is economically justified.
Tucked into footnote 37 of the report, there’s a brief discussion of feedbacks that could certainly, and dangerously, be categorized as a non-linear, vulnerable threshold to which we are blind.
The message of the report is clear. Countries must act, and soon. We can choose to stabilize the climate and still maintain prosperous economies. But we must make a financial commitment that just hasn’t materialized. We’ve been going backwards. The IPCC reports:
Government funding in real absolute terms for most energy research programmes has been flat or declining for nearly two decades (even after the UNFCCC came into force) and is now about half of the 1980 level.
At this point, that is unacceptable. The policies the IPCC has recommended have great potential and low cost. The world needs make the political and economic commitments to curb emissions. The time to act is now.