What are the key differences between security, trade and environmental diplomacy?

The three aspects of diplomacy are all interrelated on different levels. The overarching aim is to obtain security. However, the road to security has changed as the notion of ‘security’ has broadened in recent years to include ‘human security’, and looking deeper into the root causes of conflicts and instability such as environmental issues, health, ethnicity, economical, and political aspects. The concept was first acknowledged in a report by the UNDP in 1994.
Security diplomacy is at the core of traditional ‘old’ diplomacy, and has to a high degree maintained the concept of secrecy in order to create leverage for concessions and bargaining without the pressure of the public eye. History has several examples of state leaders using back-channels and thus bypassed the official bureaucratic structures of decision making. More often than not security diplomacy is conducted on a bilateral basis. Security diplomacy remains at the centre of the discipline in order to avoid the use of hard power measures.
Trade diplomacy is interconnected with other aspects like security and development which has been seen in the recent Doha Round. Some argue in connection to the democratic peace thesis that trade reduced the risk of violent conflicts as it will bring peace, democracy and prosperity as well as being interlinked with other states making states having too much to lose if engaging in military actions. Trade diplomacy can be conducted both on a bilateral as well as on a multilateral basis through regimes like the WTO. However, the organisation have in recent years been accused of being undemocratic, unaccountable and lacking transparency as well as the agreements and internal structure are favouring the wealthy west on the expense of the resource-weak developing south and can thus cause the further development of under-development crating even bigger gaps between the two blocks. Finally, trade diplomacy remains influenced by strong business lobbies and like other diplomatic dimensions remains doubled-edged having to respond both to demands from the domestic as well as the international sphere in the quest of liberalising the markets.
Environmental diplomacy is a newcomer on the diplomatic stage. Environmental diplomacy remains interconnected with security diplomacy as issues such as deforestation, global warming, desertification, etc. may risk triggering mass migrations and generate civil instability with international ramifications. Environmental diplomacy remains on a multilateral level as international issues demand international solutions as unilateral and bilateral actions will not make a difference this have been the case with the Kyoto protocol and perhaps again with the upcoming COP15 in Copenhagen. NGOs remain very influential when it comes to the agenda setting, advising and creating public awareness; however, much of the efforts may be in vain as the structure remains predominantly informal utilising non-binding instruments like the issuing of declarations, guidelines and action plans, which have been agreed on the lowest common denominator generating an inefficient outcome as argued by Barston. Furthermore, the environmental agreements have been pestered by a slow implementation pace, withdrawals and bypassing without any sanctions can be applied.
What are the key differences? I tend to agree with some of the other bloggers that the key differences between the three; is how the diplomacy is conducted with security diplomacy continuing to be conducted along traditional lines behind closed doors on a bilateral basis where as trade and environmental diplomacy often are conducted on a multilateral basis with much involvement of civil society. Finally, the three are ranging at different places within the hierarchy with security at the top, then trade, and, finally, environmental issues at the bottom despite the high degree of interconnectedness.