The chances of a double-dip recession are now more than 40 percent and policymakers have options to stimulate the economy, Nouriel Roubini of Roubini Global Economics told CNBC Thursday.

Nouriel Roubini

Second-quarter gross domestic product growth will be revised down to an a annual rate of 1.2 percent from an initial reading of 2.4 percent, Roubini said, adding that any improvement recently was due to inventory adjustments.