An aggregate integrated assessment model is used to investigate the relative merits of hedging over the near term against the chance that atmospheric concentrations of carbon dioxide will be limited as a matter of global policy. Hedging strategies are evaluated given near term uncertainty about the targeted level of limited concentrations and the trajectory of future carbon emissions. All uncer...

Ruminant production is under increased public scrutiny in terms of the importance of cattle and other ruminants as major producers of the greenhouse gas methane. Methanogenesis is performed by methanogenic archaea, a specialised group of microbes present in several anaerobic environments including the rumen. In the rumen, methanogens utilise predominantly H2 and CO2 as substrates to produce met...

Under the current framework embodied in the Kyoto Protocol and envisaged for future multilateral agreements, Annex I parties are obliged to limit their economy-wide GHG emissions and accept responsibility for exceeding their targets through various flexible mechanisms. The predominant sources of agricultural GHGs, which represent about 8% of total Annex I emissions, are methane and nitrous oxid...

Received: 11/11/2013 Revised: 13/12/2013 Accepted: 15/12/2013 Abstract Methane is the second key greenhouse gas (GHG) and enteric fermentation in livestock is one of the largest sources of methane emission, producing 15-20 % of the total anthropogenic methane. Methane production by enteric fermentation in the rumen accounts for the 2-12% loss of gross energy and consequently influence performan...

Increasing atmospheric concentrations of methane have led scientists to examine its sources of origin. Ruminant livestock can produce 250 to 500 L of methane per day. This level of production results in estimates of the contribution by cattle to global warming that may occur in the next 50 to 100 yr to be a little less than 2%. Many factors influence methane emissions from cattle and include th...