|Last – and most
- we come to agriculture and forestry
|Our review of
the carbon cycle indicated these human activities cycle about five times as
much carbon annually as is released from fossil fuel combustion.
|We already use
science and technology to increase the productivity of this the plants
under our control. Irrigation, fertilizer, and plant selection and breeding
increase the annual turnover of carbon. The first two of these are subtly
integrated with energy production. Energy for irrigation is taken from
renewable energy provided by the hydrogeological cycle. Fertilizer production
requires energy – and some is made from fossil fuels.
|At the same time
stocks of carbon in standing forests have decreased and carbon stored in
soils has been released to the atmosphere.
|It seems there
may be opportunities to modify our agro-forestry technology to keep
greenhouse gas emissions from the atmosphere. This would focus on managing
the carbon bearing waste streams.