We have four: pick one | Food fibre and forest products
The natural system is strictly bonded to production processes through a series of two-way relations.
The productive system, nonetheless, strongly depends on climate, soil and natural resources for it's well-being.
Earth's current rise in CO2 levels, and consequently in temperature, is having a harsh effect on its croplands and pastures.
Predictions about future climate change scenarios point out substantial differences in production levels from those we are used to.
While moderate warming may be beneficial to crop and pasture yields in mid-to-high regions, it will have an adverse effect in low-latitude regions which will immediately face a drop in production. Still, if global warming will continue it's actual rush, every region will be strongly affected in it's production capabilities, and SRES' 4 scenarios define at which exact point in time a sudden drop in production is due, described as the "critical point".
Apart from temperature, farming and forestry production is also severely influenced by the increased frequency and hashness of extreme climate events, as proven by the unexpected drought that Europe faced in 2003.
Food trade is foreseen to increase in response to climate change, with increased reliance of low latitude countries on food import.
These four scenarios are modeled after different socio-economic models. Every model's trend is defined by different environmental and productive sociopolitical choices.