碳贸易的核心问题是要有足够的碳封存量在抵消CO2的排放之后还能有碳额度进入市场买卖。该文结合固碳概念，从固碳技术、减量成本、对生态系统碳汇功能的影响等多方面对目前存在的和有潜力的各种减排与固碳途径进行了比较分析，认为陆地植被对CO2的吸收是最安全有效的固碳过程，它们能够在一定的浓度范围内吸收CO2，从而节省分离、提纯等 技术的费用。进而该文分别对森林、草地、农田等3种陆地植被的固碳功能与不同固碳策略对固碳效果的影响两个方面进行详细具体的比较分析，得出森林生态系统具有强大的碳吸收能力，草地与农田土壤有机碳库在固碳方面的作用也十分显著。最后结合我国实际，提出4 项适用于碳贸易的生物固碳方式，即保护天然林，推广种植速生丰产人工林；保育天然草地 、建设人工草地；建立规模化沼气产业链；注重利用边际土地种植生物质能源，促进生物质能源的开发
The Kyoto Protocol provides three mechanisms that would allow transfers or crediting of emission reductions achieved in other countries. Reductions of greenhouse gases (GHGs) emission are attained at the lowest possible cost, with equal benefit to the environment. Developing countries can benefit from the investment of funds available for project development, gain new emission_reduction technology, and earn a profit by selling their emission reductions credit. The core issue of carbon trade is whether there is enough carbon sequestration credit for trading after offsetting the CO2 emission. This paper compared and synthe sized most of the potential and existing manners of CO2 emission reduction and carbon sequestration in current aspects of techniques, cost_effective, effect on th e carbon sink of ecosystem and other aspects. Large_scale biogas cogeneration or co_firing in coal power stations with cost_effective and energy_saving measures can reach better emission_reduction benefit and carbon sequestration efficiency . The process of carbon sequestration in terrestrial ecosystem, which can remove carbon from the atmosphere and sequester it in biomass and soil, is most safety and efficiency, with no expense of CO2 separation and purification as well. Not only forest ecosystem possesses one of the most reliable carbon sequestration processes, but also the large_scale grassland soil and farmland soil do have. As a result, some projects related to CO2 emission reduction and carbon sequestration, such as establishing natural forest and grassland reserves, planting high_yield woodland, setting up artificial pasture with high productivity and stable yield, adopting way of eco_agriculture, remaining more straw in the field, making the best use of marginal land to grow bio_energy，promoting the exploitation of bio_energy and other projects, which are cost_efficient and suitable for China, should be conducted to enforce and increase carbon sequestration of terrestrial ecosystem in accordance with their respective characters.