Agricultural peatlands of the UK are highly productive, yet risk increased rates of degradation due to drainage and the climate change. The purpose of this body of work is to 1) fill knowledge gaps concerning the effects of the climate change on the Carbon cycle and horticultural production of agriculturally-utilised peatlands; 2) advise farmers on the suitability of increasing the field water table as a means of peat preservation. The research examines: 1) the influence of 2°C and 5°C warming on greenhouse gas emissions and DOC production from agricultural peat; 2) the effects of 2°C and 5°C warming and atmospheric CO2 concentration of 850 ppm on yield of radish, celery and romaine lettuce; 3) the effects of raising the water table from the field level of -50 cm to -40 cm and -30 cm on greenhouse gas emissions; 4) whether increasing the water table from the field level of -50 cm to -40 cm and -30 cm would constrain or improve yields of radish, celery and romaine lettuce. The results suggest that the future global warming in the UK will cause higher rates of peat loss and varying effects on horticultural production on peat. It is not easy to explain the lower plant biomass in conditions of elevated atmospheric CO2, however, it may be related to waterlogging and insufficient nutrient uptake from peat. Raising the water table would preserve agricultural peats for longer and lower emissions of carbon dioxide, however, this would happen at the expense of yield and increased DOC production. The emissions of methane were generally low or negative, even at higher water table levels, which shows that raising the water table to -30 cm or -40 cm would result in overall lower radiative forcing.