«A potential does exist
for significant positive feedback» from Arctic Ocean clathrates, warned Bell (1982), who was stimulated by a 1980 paper presented by Gordon J. MacDonald, see MacDonald (1980).
The total climate impact of forest losses in the north is still uncertain, Flannigan said, but if the peat lands in Russia and Canada continue to dry and burn more often, «there could be
a significant positive feedback.»
What is more we know with certainty that there are
significant positive feedbacks — water vapor, decreased albedo, etc..
In fact, if we assume that CO2 warming causes
no significant positive feedbacks — and the jury is still out on this — then 1C or thereabouts is the number we would expect to get.